Mercedes Drive Cycle for Incomplete Readiness (Failed Smog Check)

mercedes-benz-smog-check-huntington-beachMany drivers have had difficulty completing readiness monitors for their Mercedes Benz. The two readiness monitors that seem to be the most stubborn to complete are: Secondary Air Injection and Catalyst (Catalytic Converter). We located a Mercedes Benz Service Bulletin (S-B-14.00/17) that may be helpful.

Also, one customer with a 2002 Mercedes was unable to complete the secondary air injection monitor until one evening he allowed his vehicle to idle for 5-20 minutes in his driveway. He then turned off his vehicle and restarted the vehicle the next morning and allowed it to idle for another 5-10 minutes. He stated that this procedure completed the AIR readiness monitor.

UPDATE:
Our customer had a stubborn CATALYST MONITOR on his 2002 Benz. He had already driven hundreds of miles and still the catalyst monitor was incomplete. The following drive cycle did the trick:

 

CATALYST MONITOR DRIVE CYCLE

  • Vehicle warm up
  • A/C Off
  • Drive 3 minutes at 43 mph in D
  • Drive 3 minutes at 51 mph in D
  • Stop and let idle for 3 minutes in P

 

Mercedes Benz Service Bulletin (S-B-14.00/17)

SUBJECT: State I/M (emission inspection and maintenance) Facilities Incorporating an OBDII Check
A. Description of State I/M OBDII Checks & Drive Cycle
B. Models, Model Years & OBDII Systems Included
C. Drive Cycle Test Procedure
Note:
Refer to Service Information: P-SI-14.00/14 for historical information.
A. Description of State I/M OBDII Checks & Drive Cycle
Certain States around the country have or will begin to roll-out in the coming months, OBDII (On-Board
Diagnostic II) quick checks for emission inspection and maintenance (I/M) testing. The emission I/M testing
is required for customers to register their vehicles. These State I/M facilities will specifically look for whether
or not the vehicle’s OBDII system is “ready” to be tested. The OBDII system uses readiness codes built into
the vehicles computer to indicate if the system is “ready” to be emission tested. These State I/M Facilities
use hand held scan tools capable of reading OBDII codes and will indicate if these readiness codes are set
or not.
These readiness codes are needed to be set (complete) within the OBDII computer system. Without these
codes set, the vehicle will most likely fail the emissions portion of this inspection and the customer will not
be able to register or re-register their vehicle. In an effort to prevent this situation from happening, a specific
drive cycle must be performed prior to the vehicle being tested at any I/M facility checking the OBDII
system.
2 S-B-14.00/17 February 2004
If a model year 1996 through 1999 vehicle has “failed” a State I/M emission test and no faults have been
found in the system (i.e. check engine light NOT on) then a drive cycle test must be performed on the
vehicle.
Note:
A battery disconnect to service the vehicle can impact whether the readiness codes will be set, if the
vehicle is immediately taken from the service facility to an I/M testing facility for vehicle registration
purposes. In such a case, the customer should be notified and instructed not to take the vehicle
immediately to an I/M station for emission testing.
Note:
Cycling the ignition key from on – to – off prior to performing the I/M test is not recommended.
B. Models, Model Years & OBDII Systems Included
1. A drive cycle has been developed for the following model years and models:
MY1996
S420 (w/ME1.0 OBDII system)
S500, S500C & SL500 (w/ME1.0 OBDII system)
MY1997
C230 & E320 (w/ME2.1 OBDII system)
C280 (w/ME2.1 OBDII system)
S320, SL320 & C36 AMG (w/ME2.1 OBDII system)
E420, S420, S500, SL500, S600, SL600 (w/ME1.0 OBDII system)
MY1998
C230 & SLK230 (w/ME2.1 OBDII system)
S320 (w/ME2.1 OBDII system)
S420, S500, CL500, SL500, S600, CL600 & SL600 (w/ME1.0 OBDII system)
MY1999
C230 & SLK230 (w/ME2.1 OBDII system)
S320 (w/ME2.1 OBDII system)
S420, S500, CL500, S600, CL600 & SL600 (w/ME1.0 OBDII system)
2. On-Board Diagnostic System (OBDII) used on the vehicle, are ME1.0, ME2.0 or ME2.1 systems.
3. Performing the drive cycle on the vehicle will take up to 1 1/2 hours.
4. Required tools are: SDS equipment and all required cables.
C. Drive Cycle Test Procedure

S-B-14.00/17 February 2004 3
Note:
Readiness/function codes cannot be displayed for tests performed on vehicles at altitudes above 8200 feet.
Note:
Depending on engine temperature you may perform the testing starting with EVAP system (see step 7)
or start with steps 1 through 4 or continue to step 6 (Air injection Diagnostics). Remember, these tests
are all based on engine temperature.
Note:
When using an SDS to check vehicle readiness codes, note the following:
1. Open vehicle hood.
2. Either remove the SDS connector cover or the engine fuse box cover depending on the model.
3. Attach/connect SDS connector.
4. Enter into the CARS function.
5. Select correct Chassis line
6. Select the gasoline engine for engine type.
7. On the screen labeled Main Function Groups, select Option 1 Gasoline Engine.
8. Select the ME system and press enter.
9. Start the vehicle to enable communication between the module and SDS system.
10. In the Functions screen, go to option 3: Actual Values and press enter, you are now ready to begin
the testing.
11. For steps 1 through 7: For ME2 under Actual Values select option 12 Completed Test and press
enter, for ME1 under Actual Values Option 9 Performed Tests.
12. Scroll through the screens to find the applicable step information and identify whether a check mark
or F has been highlighted
Drive Cycle Test Procedure Explained
1. 02 Sensor Heater Diagnostics (do not interrupt this portion of the test):
With the engine warm (greater than 80 degrees C), and the transmission gearshift lever in Park
position, proceed as follows:
• Start engine and increase engine speed to between 2,000 to 2,500 RPM for 2 minutes.
• After the 2 minutes, run engine at idle speed, with no applied load for 6 minutes (Air
conditioning OFF, no throttle movements etc).
• After this time period has been obtained proceed to step 2 below.
Note:
If using a Hand-Held Scan Tool verify Step 1 test completion. This will be indicated by a check mark in the
display field or the word PASS.
2. Lambda (02) Sensor Signal (do not interrupt this portion of the test, to be conducted directly after
step 1 above has been performed):
With engine temp greater than 80 degrees C, and with transmission gearshift lever in position D,
• Drive vehicle for 3 minutes at 70km/h (43 mph).
• After the 3 minutes has been reached proceed to step 3 below.
Note:
If using a Hand-Held Scan Tool verify Step 2 test completion. This will be indicated by a check mark in the
display field or the word PASS.
3. Catalytic Converter Efficiency Diagnostics (do not interrupt this portion of the test and must be
conducted directly after step 2 above has been performed):

With engine temp greater than 80 degrees C:
4 S-B-14.00/17 February 2004
• Drive vehicle with transmission still in position D for 3 minutes at 80-90 km/h (48-54 mph).
Note:
If using a Hand-Held Scan Tool verify Step 3 test completion. This will be indicated by a check mark in the
display field or the word PASS
4. Self-adjustment of the air/fuel mixture (idle speed & self adaptation) (do not interrupt this
portion of the test and must be conducted directly after step 3 has been performed):
With engine temp greater than 80 degrees C, proceed as follows:
• Place transmission gearshift lever into Park position and allow engine to idle (with no load
applied to the vehicle, i.e. Air conditioning OFF) for 3 minutes.
Note:
If using a Hand-Held Scan Tool verify Step 4 test completion. This will be indicated by a check mark in the
display field or the word PASS
5. EGR System (Emission Vacuum Diagnostics): No DTC codes should stored for the intake
manifold pressure sensor and EGR pressure transducer during this portion of the test. With the
engine temperature at 80 degrees C:

• Start and Drive vehicle (in D position) and then accelerate smoothly up to 2000 rpm, and
then decelerate smoothly back down to 1100 rpm.
Note:
If using a Hand Held Scan Tool to verify test completion. This will be indicated by a check mark in the
display field or the word PASS
• After this test step has been completed, turn ignition OFF, wait 10 seconds and repeat this
test step (5.) again.
6. Air Injection Diagnostics: (do not interrupt this test when performing this test step 6).
Note:
First: Place a suitable auxiliary fan in front of the vehicle to force engine cool down. (Engine cool down can
also be simulated by using a decade box to simulate engine cool down).
Continue test step: With engine temperature less than 40 degrees C, the air conditioning OFF and the
transmission gearshift lever in Park position; and auxiliary fan removed from front of vehicle,

• Start engine and accelerate engine speed to 1400 rpm.
• Allow engine to run at this increased rpm until coolant temperature reaches between 70 to
106 degrees C.
• Allow engine to run with increased rpms for 7 minutes (or drive the vehicle for 7 minutes).
• After the 7 minute time period has been reached, stop the vehicle, place gearshift lever into
Park position and allow engine to idle (with no load) for 6 seconds. Do not use A/C.
• After this step turn the ignition OFF, wait ten seconds and repeat this test step.
• Note that when testing the air injection system, the engine coolant temperature must be at
the same temperature (degrees) as when before the ignition key was switched off in the
prior test step.
Note:
If using a Hand-Held Scan Tool to verify Step 6 test completion. This will be indicated by a check mark in
the display field or the word PASS
S-B-14.00/17 February 2004 5
7. Fuel System Leak test (EVAP): No DTC codes should be present in memory for the EVAP
canister purge valve, fuel tank pressure sensor, or the shut-off valve.
Note:
Prior to performing this test (7) step:
• Ensure the fuel tank fuel level is between ¼ and ¾ full and
• The engine temperature less than 100 degrees C with air intake temperature less than 45
degrees C.
• With gearshift lever in Park position, start and idle engine for 20 minutes (with no load).
Note that if after the 20 minutes of idling time has elapsed and no readiness codes were
set, consider driving the vehicle for an additional 20 minutes.
• After these 20 minutes has elapsed, turn ignition OFF, wait 10 seconds and repeat this test
step again.
Note:
If using a Hand Held Scan Tool to verify Step 7 test completion. This will be indicated by a check mark in
the display field or the word PASS
ir.

72 Replies to “Mercedes Drive Cycle for Incomplete Readiness (Failed Smog Check)”

  1. Johnny

    To clear the cat, you must do steps one and two first, regardless if they are cleared or not. It’s really annoying. At least that what I discovered.

    Reply
    • dewok Post author

      Hi Raymond

      For the Mercedes air injection readiness monitor we have had success with the following procedure: A/C off. Start vehicle in the morning and allow to reach operating temperature at idle (10 minutes). Drive vehicle through normal drive cycle procedure. At the end of the drive, allow vehicle to idle in park for 10-15 minutes. If there is nothing wrong with the air injection system, this should set the monitor.

      Reply
        • dewok Post author

          Hi Pancho,

          I’m not sure if it’s the same procedure for the 2007 Mercedes. We use this drive cycle as a guide for all Mercedes we are driving.

          Reply
      • Shem Duncan

        Hey Raymond do u know how to ready a cat monitor on the 2011 c300 I jus can’t seem to get this one ready and my smog is due

        Reply
      • Denise

        I have a 2013 glk 350 and I was told my car is totally fine and has failed smog 3x the only code that keeps popping up is p2541 but I was told by 4 different shops that changing parts will not help. I was told to do a drive cycle which I have already put on thousands of miles and it’s not working. I was told to drive 200 miles with air blasting now I read I need to put on cruise control, defroster and no air. Please help. I am not very automotive savvy.

        Reply
  2. Jim

    2013 e350 Bluetec Catalyst monitor is being stubborn and will not complete. Is there a certain drive cycle on the Bluetec that is different?

    Reply
    • dewok Post author

      Hi Jim,

      For Mercedes diesel vehicles we have found that having the air conditioning on can prevent the running of some monitors. With that said your vehicle should pass smog even with the Catalyst monitor incomplete. 2013 diesel vehicles are allowed any two monitors incomplete.

      OBD Readiness Monitors Test Standard

      Gasoline Vehicles
      • Number of incomplete monitors allowed to pass on gasoline powered vehicles:
      – Any one for 1996 to 1999 (BAR-97 test)
      – Only evap. for 2000 & newer (BAR-OIS test)

      Diesel Vehicles
      • Number of incomplete monitors allowed to pass on diesel powered vehicles:
      – Zero for 1998 to 2006 (BAR-OIS test)
      – Any two for 2007 and newer (BAR-OIS test)

      Reply
      • Lance Corral

        2000 mbz e320 i/m readiness air section will not reset. It`s been over 3 mo. and 2500 mi. and 1998-2006 vehicles must have all readiness lights green. This is beyond stressful. I want to go to the Mbz factory and beat the shit out of person who came up with this garbage. They call this burden a ” stubborn problem”. I call this a known problem with no integrity in fixing it.

        Reply
    • Tiffany Martinez

      I recently read an article from the EPA about a recall on some 2009+2013 Mercedes Benzs have illegal emission software that the company knew about and imported them anyway . They reached a settlement with the epa and carb. Search for Emission modification settlement and you’ll find the information

      Reply
  3. [email protected]

    hi, just wondering if it’s possible to do all the 3min. 43mph or 51mph run on a hoist ? it’s very hard to find a road that I can do that drive cycle around the california bay area any day of the week now.

    Reply
    • dewok Post author

      Hi Sam,

      I’ve never seen a drive cycle successfully completed on a hoist. Some techs are able to complete everything on a dyno.

      Reply
      • Sam

        Ok. I only have easy access to a hoist now. Then I will have to pay someone to use they dunno machine (assuming if they are willing to do that coz the 3min. / 3 min. deal will interrupt their own business. Tough for me. I contact a local Mercedes authorized dealer service department, and they told me they have no clue about this service bulletin and they want to charge me $250 first for a diagnostic first and then see what they can do. I’m not so sure about that.

        Will changing a ECU and have it programmed solve this IM READINESS issue?

        Reply
        • Sam

          The good news, IM Ready. pass smog with very little (like 0.02) emission reading. Here’s what happened with my retarded ECU problem.

          BEFORE – no check engine, IM NOT READY 0/3/5 reading, car runs smooth, pass all emission test except computer not ready = FAILED SMOG. Tried drive cycle driving, also take long trips, thousands of miles later, still no go.

          AFTER – changed 2 O2 sensors down stream with old taken down to test, B2S2 failed, check engine ON, IM is READY 0/8/0. Install a new O2 sensor, car runs smooth as before, now B1S2 failed, check engine ON again, IM is ready again.

          Ordered 3 more new O2 sensors, and replaced them all. Drive normally for 3 days about 100 miles, IM is now READY 0/8/0 reading. Bring to smog center, PASS with practically no emission readings (very clean exhaust as before).

          Well, I actually bought 2 computer units, and they won’t work without dealer programming. One local dealer told me that they can do the service not drive cycle for me for $210, but luckily I did not choose that route as it wont’ solve the problem if they did. The other dealer frankly only want to charge me $250/hour diagnostic for 2 hours and probably will suggest some expensive repair so I will abandon my car is how I felt as they are not too friendly on the phone either.

          Anyhow, feel free to ask me questions, as this took me a couple of months time and thousands of miles driving, and many trips to the mechanics shop (local guy, friendly). My car does get a bit better gas mileage now, so maybe the whole deal was only with somewhat not 100% efficient O2 sensors after all. My car now is California smog and registered again, runs smooth, quiet and always a safe and luxury car to drive.

          Good luck to all.

          Reply
          • Francisco Wilfredo Martinez

            I’m pretty much in the same position. i had the engine replaced and after months of driving I can’t get my 2012 C250 to pass smog in California. The fuel system monitoring is not ready yet. done the driving cycle and still a no go. Do you have any suggestions besides the O2 sensors. if you could please send me an email if you have any suggestions that would be great. [email protected]. I would appreciate the help. thank you

          • dewok Post author

            Hi Sam,

            For most vehicles, the fuel system monitor will complete upon initial startup. Hopefully someone in the community will have a better answer.

          • Lance V. Corral

            Good to hear. I have the same problem as you did. I am on the same page as you with the o2 sensors. I repaired a BMW with 12 codes and when i was down to just 2 codes(evap and air) I replaced all 4 o2 sensors. I was able to return vehicle to customer with a passing smog test. I guess some times we forget that parts do wear. who knows how long the o2 sensors have been in my car. I have only had it 3 mo. Im going to replace them as preventive maintenance. I will bet my secondary air light turns out. I will let you all know. Thank you for your post.

          • Lenard B Delfin

            I have a 2007 SLK280 and this is the first time it failed the smog test. The smog center told me the O2 sensor isn’t ready and I need to drive it for 60-80 miles. I did and still didn’t reset. Was advised to keep driving for a couple more hours and it should reset. I did and still unresolved. They then gave a list of shops to help me. I spoke to 2 different mechanics and they both told me to continue driving for a couple of days and it should reset. I wish car makers have an official resolution to problems like this. It’s frustrating that you are told to keep driving and it will reset. Meanwhile my registration is due in a couple of days. There should be a better way to fix this phenomenon! I’m beyond frustrated. Please help:-(.

          • Richard

            I have a 2006 CLS 500 and I can’t get 3 monitors ready CAT EVAP and AIRi can’t get the car tagged with out emissions testing this is becoming a nightmare. Please help

          • dewok Post author

            Hi Richard,

            Don’t worry about the EVAP monitor. Follow the directions and comments on this post and as long as the vehicle is operating properly, the Catalyst and Air Injection monitors should run.

            For now, we stopped offering drive cycles for European vehicles because the last few have been way too time consuming.

          • CSM

            I saw this post while googling. I know this is old, but I hope it helps others. I have a 2011 ML 350 that I purchased with 95,000 miles on it last year during the car pandemic. I ran a car fax and it came up flawless. Not to mention the car drove beautiful. I knew I had to do a few things to it, I know it’s not a new car. The title was issued in Florida, I’m in NY. The previous owner didn’t need inspection for Florida. I plugged in my scanner and it came up not ready. I thought ok I have to drive it for a little bit. I purchased new tires, had the oil changed just wished I didn’t use 0W-40 fs, need drivers seat sewn, exhaust clamp, needed an oil separator, drop of transmission fluid (need a pan). The cat was not in great shape so I purchased two different cat cleaners. I only use super in my car anyways. I never had a check engine light on ever. So I thought ok no worries. I drove twenty miles and still not ready. I did my cat cleaners and more drive cycles, but still not ready. I thought there is no way this needs a computer because it drives to good. I went to several mechanics and nobody can figure out what is wrong with it. I didn’t want to keep putting money into the car and it still not passing inspection. Of course I have to renew my registration, but can’t do it unless you have a NYS Inspection. Believe it or not I drove my car 8,000 miles, yes 8,000 miles. I even put two new Bosch upstream sensors in thinking they were probably never changed. It still would not ever be ready. During the course of drive cycles I even got notice the air bag had to be changed due to a recall and something with the brake recall. I had the Mercedes guy plug in his scanner just to see if anything came up. Nothing, still not ready. I had to get whatever it needed done or turn my plates in. I ended up having the software updated. Once I did that the check engine light came on. Scanned it, just needed a purge valve. Drove it twenty miles and finally car was ready. Got my inspection and went to the DMV immediately to renew my registration. I did end up getting the purge valve from the dealer only because of the hassle I went through with the car. Each dealership is privately owned so they were priced differently. I wish I would not have drove it all those miles, but it is what it is. Now just got to fix the seat and small transmission leak. I got lucky it was just a computer update.

          • dewok Post author

            Thank you for sharing your story.

            So, in summary, if everything seems to be working fine (sensors, actuators, mechanical, etc), then it’s worth looking into software.

            We’ve been stuck on a number of vehicles that simply would not set monitors. The solution: PCM reflash. Although a reflash doesn’t work every time, it’s worth looking into if everything else checks out.

  4. Senator

    I have a 2001 S 430, with no check light on and I’ve been driving since January and failed 2 inspections having 3 readiness evap, secondary air system and egr, I even reset the codes and the same 3 again, do anyone have a clue to what’s going on

    Reply
    • dewok Post author

      Hi Senator,

      Have your mechanic check Mode 6 data (if accessible for your vehicle). If there are no DTCs, current or pending, sometimes Mode 6 will give you clues of what’s wrong with the vehicle.

      We’ve also have had luck with Mercedes drive cycles by allowing the vehicle to sit over night and in the morning start up (No A/C or other accessories), warm up for 10-15 minutes and then do a drive cycle. When finished, let the vehicle idle for 10-15 minutes. No guarantees, but this has work for us a couple of times in regards to a stubborn Mercedes AIR monitor.

      Good luck.

      Reply
  5. Daniel B

    Hi!

    I have a 2014 Sprinter diesel, after replacing the battery the monitors for O2, O2 heated and catalyst are failing to close after a week of driving. Any thoughts?

    Reply
    • dewok Post author

      Hey Daniel,

      We’ve had multiple customers with Sprinters that had readiness monitor difficulties. We haven’t ran a drive cycle in-house on a Mercedes Sprinter, so I don’t have an exact formula. Remember, as of March 2019, all you need is two incomplete monitors for a 2014 diesel to pass the OBD portion of a California smog inspection.

      What we have told customers (an it seemed to have worked) is: NO A/C, allow vehicle to warm up (10-15 minutes) in the morning after sitting overnight, and drive (RPM under 3,000) to a highway and then drive 55mph for about 10 minutes.

      Good Luck,

      Danny
      Just Smogs in Huntington Beach

      Reply
  6. Joe P.

    We are having trouble with S-500. This car was left still for 2 years. Battery all drained out. We are trying to buy this car.

    Changed the battery, drove a thousand miles, performed several times of drive cycle, changed all O2 sensors just like what the page suggested. Still no good, NOT ready.

    Can anyone help? Suggestion is appreciated. Thanks.

    Reply
    • dewok Post author

      Hi Joe,

      It’s not uncommon for a Mercedes to have trouble completing OBD II readiness monitors. When we have a stubborn vehicle, we usually clear “Adaptives” with a scan tool and try the drive cycle again from scratch. Please note that not all vehicles have the option to clear adaptives with a non-factory scan tool.

      Good luck. Please let us know what works.

      Danny
      JUST SMOGS

      Reply
  7. Suzanne Lewallen

    I am at a complete loss….I am new to Mercedes and looking to buy one from a friend. was headed to get smogged and CEL came on. Car has been running fine.

    Code was P0400. Had a friend take out the EGR valve and cleaned it up (wasn’t that bad) Cleared out the code.
    .. Now I guess I need to do this “drive cycle”??

    Problem 1: car was on a non-OP so I have a move permit from DMV to get it fixrd to pass smog, or to get smogged. Should that cover the driving to get it ready as well? I’ve paid the registration so just need to get smog done.

    2. Sounds like these steps need to be done all at once? (not a couple today, couple tomorrow.)?

    I am so not a car mechanic in any sense, so any advice/tips would be appreciated.

    Thanks

    Suzanne
    MsSuzAllen@gmail

    Reply
  8. Sheila

    I have purchased a pre owned 2013 c250 and cannot pass New Jersey’s inspection. I have failed twice. I pass on everything except the fuel system not ready. would anyone have a suggestions on how to pass. I’ve been told to just drive, however I have driven over 1800 miles and still not ready.

    Reply
    • dewok Post author

      Hi Sheila,

      On most vehicles, the fuel system monitor will become ready upon vehicle startup. I would first try clearing all monitors and adaptives via a scan too. Then attempt another drive cycle. If this doesn’t work, I would take the vehicle to the dealership.

      Reply
      • Roman

        2011 GL350 bluetec
        Same problem
        Shows 3 not ready 02s / HRT / CAT /
        Drove 400miles still not ready
        And one time Code shows up P2BAD
        And went a way , but still not ready for smog
        Any clue?
        Thank you

        Reply
  9. R.A

    Passed the smog On 2011 gl350 bluetec.
    I was driving 500 miles cycle and still couldn’t get smog ready after resetting the ecu the 2 monitors never goes a way the cat and 02s plus after driving cycle, pending code comes on for noX sensor
    I give up and took it to the smog station and it did passed with dose errors
    I found out that 2007 and up diesels allow any two monitors not ready and one pending code with no check engine light on
    It should pass the smog

    Reply
  10. Scott L

    For the Secondary Air Injection: I went through the Mercedes procedure 3 different times and the monitor didn’t set. On the 3rd time, after holding rpms at about 1500 (for 7 minutes) and returning to idle, I put the vehicle in reverse, held the brake and accelerated under load (power braked it) for about 20-30 seconds and literally watched the monitor change on the scantool. I would assume driving it would have done the same thing, but this is what worked for me. Thanks. The vehicle is a 2000 ML430.

    Reply
    • dewok Post author

      Hey Scott, thanks for sharing. We will try this next time we get stuck on a Mercedes Air Injection monitor.

      Reply
  11. Carlos Gomez

    I have a 2006 CLS500 that had two misfires I replaced plugs and coil packs. Cleared the codes with an OBDII reader and drove about a 120 miles. I still have a inc on catalyst and evap. How much further do I need to drive or is there a process for this model?

    Reply
    • dewok Post author

      Mercedes can be tricky. I would let the vehicle warm up in the morning (AC off) and drive on the highway at 55 mph for 10 minutes. If the cats are in good shape, and everything else is working properly, you should be good to go.

      Reply
      • Richard

        I have 2006 CLS500 just purchased and 2 monitors not ready EVAP and AIR. Was 6 at first not ready drove the car around town went down to only two not ready or incomplete. What should I do ?

        Reply
  12. Angela

    Hi! I have 2000 CLK which I don’t drive often. The catalyst hasn’t been activated. Will try your catalyst monitor drive cycle below. Two quick questions.
    1. Can I use cruise control to hold the speed?
    2. How long do I warm up the car for? 10 mins? 20 mins?

    THANKS!

    CATALYST MONITOR DRIVE CYCLE

    Vehicle warm up
    A/C Off
    Drive 3 minutes at 43 mph in D
    Drive 3 minutes at 51 mph in D
    Stop and let idle for 3 minutes in P

    Reply
  13. Sam

    Hi,

    Thank you for this post and for your guidance.

    My mom’s 1998 Mercedes C230 failed its most recent smog check. The report shows Functional Check failed. In the details section, everything except one item shows as either “Pass” or “Not applicable”. The only Fail score is for OBD System checks.

    My mom is an old lady and doesn’t drive much. There’s no freeway driving at all. The battery died early in the year during covid lockdown and apparently this caused the computer to reset the history according to the tech..

    Do I need to go through the entire drive cycle to fix this issue or is there a shorter procedure that I can use to get around this one particular issue?

    You can view the smog report here if it helps.
    https://drive.google.com/file/d/1Hftmw8PIwBVykNj7XbYbq1xowZNUfj5z/view?usp=sharing

    Thank you for your time and consideration.

    Reply
    • dewok Post author

      Hi Sam,

      It’s great that you included the smog check Vehicle Inspection Report (VIR) but unfortunately in this situation it does not provide detailed information about which monitors are incomplete / not ready.

      Based on your mother’s driving habits, I’m assuming that the catalyst monitor is not ready.

      I would make sure the AC is off the night before the drive cycle. Start the vehicle the following morning and let it warm up for about 15 minutes. Drive to the freeway (light traffic preferred) and keep the vehicle steady at around 55 mph for 10 minutes. This should do the trick.

      Good luck.

      Reply
      • Sam

        Hi,

        Just wanted to follow up and let you know that we had a re-test this Saturday and the car passed smog after following your suggested steps. I followed your procedure and drove straight to the test station. There was very minimal short distance city driving (2-3 blocks) outside of your suggested drive cycle in between the two tests, so I’m pretty confident that your suggestion is what got us through this hurdle.

        Thank you very much for your expertise. Very grateful.

        God bless

        Reply
  14. Siel

    Hello, So i have c250 2012 and my catalyst not ready for smog (o2sensor, fuel system, catalyst and oxygen heater sensor)
    Can someone help me!

    Reply
  15. Bob

    I have a 2016 AMG GTS that is unable to pass smog. It shows OBD II Monitors Not Ready for EVAP system, O2 sensor, and O2 heater. I thought the battery may have died during transportation of the vehicle to me. I have driven the vehicle for over 100 miles and it still wouldn’t clear.

    Reply
    • CLS

      Hey Bob,
      I have the same issue with battery change now my O2 sensor and O2 heater are incomplete, but the rest are complete after 300+ miles.

      Reply
  16. Jose

    96 sl500 has 5 monitor not ready drove car, keep on shop ,replace 4 O2 Sensors and still not ready ,did the drive cycle,any help?

    Reply
  17. Toliy

    I can’t pass drive cycle on my 2013 c350
    Drove it for a weeks and did some drive cycles
    Is there anything I can do about it to pass smog ?

    Reply
        • dewok Post author

          We generally set the O2 Heater monitor by allowing the vehicle to sit overnight (A/C off before turning the vehicle off) and starting the vehicle in the morning. Allow to idle in park for 20 minutes.

          Give it a try.

          Reply
  18. Bob Medina

    For 2002 C32, 2003 SL500, and few others.

    Warm up vehicle.
    No A/C and don’t use cruise control.
    Drive 3 minutes at 43 MPH in D
    Drive 6 minutes at 51 MPH in D
    Stop and let idle for 3 minutes in P.

    I don’t remember what one monitor did not clear after the cycle, but when I arrived home, it showed it was OK. I don’t know if it requires to drive so many miles after the cycle. In CA, Evaporative is not required to be ready.

    Reply
  19. Will Fuller

    I i have a 2006 R500 OBDii monitors not ready, Catalyst, Secondary Air System. Has not completed the emissions self checks. What do I do now? Drove it 270 miles and still not ready. Use the small obd scanner to erase codes after changing a bad O2 sensor.

    Reply
    • dewok Post author

      Hi Will,

      Catalyst and Air injection monitors tend to be the last two to complete for Mercedes. Go ahead and review previous posts for specifics on how to drive your vehicle to complete the monitors.

      Reply
    • Bob Medina

      Try the author’s procedure.

      Vehicle warm up
      A/C Off
      Drive 3 minutes at 43 mph in D
      Drive 3 minutes at 51 mph in D
      Stop and let idle for 3 minutes in P

      Maybe, warm it up to >80 deg C. Maybe a coincidence, it did not work when I used the cruise control on first cycle.

      Reply
  20. Toliy

    So in the morning I started my c350 2012 letted it idle for 20 something minutes after did 43mph in D for 3 minutes then 51mph in D for 3 minutes after letted it idle in P foe 3 minutes
    And my $7E8 oxygen sensor heating monitors and $7E8 oxygen sensor monitor
    And $7E8 Evaporative system monitor
    didn’t pass
    Still stays at INC both of them

    Reply
  21. ray

    I have a 1996 Benz E320 but I cannot turn the cat code off I don’t know what to do and I drove it almost 10 thousand miles but still nothing

    Reply
  22. Rick Winslow

    I have a 230 SLK Mercedes that has failed 5 smog tests re: catalytic converter. We’ve tried driving different speeds and distances followed by idling many times without air conditioning- no luck. We have Mercedes guidelines and follow exact directions again. Any suggestions?

    Reply
    • dewok Post author

      Hi Rick,

      Are 5 monitors incomplete? If you have driven the vehicle and all 5 monitors are still incomplete, the vehicle may have a software issue.

      Reply
  23. Felix

    I have a 2001 S500 Mercedes, replaced battery and now can’t pass smog because the Catalyst not ready or the O2sensor, I have driven it 300 miles,,, any suggestions??

    Reply
    • dewok Post author

      Hello Felix,

      I would follow the drive cycle instructions included in the original post. European vehicles can sometimes be challenging.

      Sorry I couldn’t be more helpful.

      Reply
  24. G500

    Encountered similar issues smogging my 2002 G500 and thought I’d follow-up to share my experience since there seems to be quite a number of subjective takes on what works. In my case I had disconnected the battery awhile ago to charge it and encountered 3 error codes when trying to smog, Catalyst Monitor, EVAP System, Secondary Air System.

    For me none of the alternatives people posted worked after my initial attempt trying to do a Drive Cycle but I think that first failed attempt had some steps that were missed. It was only redoing the Drive Cycle Test Procedure from Steps 1 to 4 to a tee that solved all three issues in one go:

    1. 02 Sensor Heater Diagnostics…
    2. Lambda (02) Sensor Signal…
    3. Catalytic Converter Efficiency Diagnostics…
    4. Self-adjustment of the air/fuel mixture…

    I was a bit concerned about potentially not doing these successively or timed exactly since I don’t have a long enough stretch of road but it proved not to be an issue. Step 1 done in my driveway, Step2 my first attempt wasn’t a consistent 43mph (rather dangerous speed on the freeways here) so I pulled over and re-entered the freeway at the start of a steep grade and redid Step2 for 3mins, with my speed fluctuating 3mph give-or-take. I had to get off the freeway, stop and drive to the other side, re-entered and did Step3 at 51mph for 3mins, give-or-take. After exiting the freeway and some stop-and-go to find a safe place to pull over, I let it idle for Step4, checked the OBDII scanner while running and all was “ok”! I didn’t want to risk anything resetting so drove directly to the smog station, keep it running and it passed with flying colors.

    Reply
  25. M Fleury

    Having issues getting my 2017 LTV Unity TB Mercedes 2016 diesel chassis to pass smog. OBD2 needs to be reset. Are there specific instructions for this model or should I just follow the instructions above.

    Reply
    • dewok Post author

      Hello,

      Yes, I would use our post as a guide.

      Mercedes can be difficult and take time to set monitors.

      It may be worth checking if there are any software updates for your vehicle.

      Reply

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