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.

21 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
  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
  3. sam@southbay.California

    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. ciscomar222@gmail.com. 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.

  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

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