Post repairs we usually complete drive cycles to confirm accurate repairs and/or to complete a smog certification for our customers. We generally approach drive cycles similarly for domestic and Japanese vehicles. We begin with a cold start followed by an idle warm up (10-15 mins with AC off). Then drive steady on the way to the highway or PCH. We do our best to maintain 55 mph steady for as long as possible. If everything is working correctly, this will usually complete the drive cycle. Some vehicles are a bit more stubborn and require manufacturer specific procedures. Below is a detailed factory drive cycle for a Honda.
COLD START: Begin from Cold Start, and ignition in OFF position for at least 1 hour
- Fuel tank is between 1/4 and 3/4 full
- Engine coolant temperature must be below 122°F and within 11°F of the ambient air temperature
- Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run
IDLE TIME: Run your Honda’s engine (do not drive) for 2 1/2 minutes with the air conditioner on and rear defroster on. During this period the ECU will be running the Oxygen Sensor Heater self-test, Air Injection System Passive Air test, EVAP Purge “No Flow” test, Misfire Detection.
ACCELERATE: Turn off the air conditioner and rear defroster and begin driving
As soon as possible apply half throttle until 55mph is reached. The ECU will now run self-tests on the Misfire Detection, Fuel Trim, and EVAP Purge Flow
HOLD STEADY: Now hold your vehicle speed steady at 55mph for three minutesDuring this time the Oxygen Sensor O2 response, Air Intrusive (AIS System), EGR Flow, Purge Valve, Misfire Detection, and Fuel Trim diagnostics will be performed
DECELERATE: During this step you want to slowly let off the accelerator pedal. Do not brake or shift your Honda in order to slow down. It is important to let the vehicle coast along gradually slowing down to 20 mph. The ECU will once again self-test the EGR System, EVAP Purge System and Long Term Fuel Trims.
ACCELERATE: Go ahead and accelerate again at 3/4 throttle until 55-60mph is reached. This will perform the same self tests as during the first acceleration step.
HOLD STEADY: Hold steady speed once again. This time at 55mph for five minutes. During this time, in addition to running the self-tests as during the first HOLD STEADY step, the ECU will perform the catalyst monitor diagnostics. If the catalyst (Catalytic Converter) is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst,or in order to Complete the CAT Monitor.
DECELERATE: This will perform the same diagnostics as in the first Deceleration. Remember not to press your Honda’s brake or shift gears during deceleration.
If all systems and sensors are working properly on your Honda, this should complete the drive cycle. To ensure all monitors are complete use a scan tool to view the monitors. You may want to complete the drive cycle 2-3 times.
If you are unable to complete your drive cycle or the check engine light (MIL) illuminates, feel free to give us a call to schedule our drive cycle/diagnostic service: (714) 596-1019.
Can they also be used for a Mercedes Glk?