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Emissions Component

GMC Safari Failed Smog Due Monitor Incomplete

I fixed a broken electrical line on my starter to do this I had to disconnect the battery of my 2004 GMC safari. After I got it fixed I took it to get the smog done. The registration is due in December. It failed because 4 of the monitors were not set. The owner told me to drive it around for 3 or 4 days then take it back. I did be he said that The Evap system monitor had not set so to keep on driving it but to look on the internet for the drive cycle instructions. I did but I also found that on your site that in California on 2000 and newer cars only the Evap System Monitor was allowed INC. I took the article to the station (now a week after the first attempt) but the owner said that that only counts on the first attempt that when we go back the second time ALL monitors have to be set.

Is this true?

I have now done the drive cycle 2 times and the EVAP SYSTEM MONITOR won't set. No codes and nothing pending. What do I need to do?


We recommend using another smog station. The EVAP monitor exception applies to every smog inspection, initial or retest, and any test in between. It is likely the smog station in question is unwilling to inspect your GMC Safari with an incomplete monitor due to the way the BAR calculates STAR station scores. Inspecting vehicles with incomplete monitors affects a station's STAR status.

As far as getting all the monitors on your GMC Safari to become complete, we'd like to give you some information. It may several complete drive cycles in order to get the EVAP monitor to run and be READY for the smog check.

First off, using a scan tool, make sure that there are no current or pending trouble codes. Next ensure your GMC Safari has between 1/4 to 3/4 fuel in the gas tank, and finally only start the drive cycle from a cold start; start a drive cycle in the mornings, after your Safari has been sitting overnight.

Use extra caution when completing the drive cycle on public roadways. If you feel you may not be able to perform the GMC Safari drive cycle yourself, please seek assistance from a GMC dealership or experienced smog check repair station.

How to Perform GMC Safari Drive Cycle

Make sure to start the drive cycle with the engine cold. Engine coolant temperature must be below 122°F at startup. Also ensure fuel is between 1/4 and 3/4, and do not leave the key in the ignition before starting the drive cycle for longer than 5 seconds.

A. Start the engine and allow to idle for 2 1/2 minutes, while the A/C and rear defroster are ON. The drive cycle is now testing the O2 heater, Air Injection, EVAP Purge, and Misfires.

B. Begin driving. Turn off the A/C and rear defroster and begin to accelerate to 55mph. During this time the drive cycle is checking for misfires, fuel trim, and EVAP purge flow.

C. Hold your speed steady at 55mph for 3 minutes. The drive cycle is now checking oxygen sensor switch time and response, air injection, EGR flow, EVAP purge, misfires, and fuel trim.

D. Start slowing down. Begin to decelerate by letting off the gas pedal and without touching the brake pedal. Your GMC Safari must slowly coast down to 20 mph.

E. Speed up. Apply 3/4 throttle accelerate back to 55mph and keep your speed steady for 5 minutes. Along with the same tests being performed as in step C, the catalyst monitor is now running. As mentioned above, it may take several complete drive cycles in order to complete the catalyst monitor portion of the GMC Safari drive cycle.

F. Start slowing down. Begin to decelerate by letting off the gas pedal and without touching the brake (or clutch). Your GMC must slowly coast down to 0 mph.

The drive cycle is now complete. Using a scan tool check the status of the monitors. If one or more are not yet complete/ready, perform the drive cycle again. Unless the air injection or EVAP monitors are not complete, it will be necessary to start again from a cold start. For all other monitors, start again from Step A, and while your engine is already warm.

posted by SmogTips Support

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