Again, don’t press the clutch or brakes or shift gears. This will perform the same diagnostics as in step 5. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. Hold a steady speed of 88km/hr (55mph) for five minutes. This will perform the same diagnostics as in step 3. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed. It is important to let the vehicle coast along gradually slowing down to 32km/hr (20 mph).

During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed. Hold a steady speed of 88km/hr (55mph) for 3 minutes. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed. Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. This will test the O2 heater, Passive Air, Purge “No Flow”, Misfire and if closed loop is achieved, Fuel Trim. The more electrical load you can apply the better. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run. In order to be classified as a cold start the engine coolant temperature must be below 50☌ (122☏) and within 6☌ (11☏) of the ambient air temperature at startup. To perform an OBDII Driving cycle do the following: A complete driving cycle can be done in under fifteen minutes. The following is the recommended driving cycle for General Motors.Ī complete driving cycle should perform diagnostics on all systems.

Fuel system monitor not ready