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Hi There,

perhaps anyone can help me. I had some repairs done to my vehicle, and the technician has reset the codes. At this time, no codes are recorded, and everything seems to be fine. with the exception of ONE thing: I need to do an emission test on my '08 Enclave, and after resetting computer, all of the emission monitors went in to "incomplete" state.

I know, it is just as it expected. with one exception, it has been a week of driving, and every monitor came back as "completed" within a day with the exception of EVAP monitor. this sucker stays "incomplete" no matter what I do.

I tried at least 3 different driving cycles that i could find online for GM vehicles to get this bugger to switch to "Complete" or "Ready" just to fail every time. I did that specifically at night, when highway is empty, as this requires highway driving.

Anyone has any idea how to make this stupid EVAP monitor switch to "completed"? Or, perhaps, someone has a '08 enclave specific drive cycle procedure, since i could not find it?

I hear, people drive 1000's of km or miles and still do not get this stupid thing to switch to "complete"...

Thanks in advance.

--Andy
 

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yeah-- I was going to say- it requires very specific events to occur in order for that test to take place.
As youve found out-- it can be difficult.

Ive seen the test where you drive at a certain speed for x then y etc..

Good luck.
 

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EVAP monitor procedure


Ken Mosher





The GM EVAP monitor procedure is a known trouble spot for all GM vehicles (regardless of any tunes or the AFM Disabler being installed). It can take several cold soak drive cycles AND a tank of gas to set at times just due to all the complicated parameters that have to be set in order for the monitor to transition from NOT READY to READY
Below is the GM procedure:
Inspection/Maintenance (I/M) Complete System Set Procedure
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provide an overview of each diagnostic category.

Description
The purpose of the Inspection/Maintenance (I/M) complete system set procedure is to satisfy the enable criteria necessary to execute all of the I/M readiness diagnostics and complete the drive cycles for those particular diagnostics. When all I/M monitored diagnostic tests are completed, the I/M System Status indicators are set to YES. Perform the Inspection/Maintenance (I/M) Complete System Set Procedure if any I/M System Status indicators are set to NO.

I/M Data List
To determine if the I/M readiness diagnostic tests can be run this ignition cycle, use a scan tool to observe the I/M monitor enabled parameters in the I/M Data List.

Conditions for Meeting a Cold Start
• The ignition voltage between 11-18 volts.
• The barometric pressure (BARO) is more than 75 kPa.
• The start-up engine coolant temperature (ECT) is between 4-30°C (39-86°F).
• The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
• The difference between the IAT and the ECT is less than or equal to 6°C (10.8°F)
• The ambient air temperature is between 4-30°C (39-86°F).
• Fuel level is between 15-85 percent
• Without RPO LMG--The fuel alcohol content is less than 15 percent.
• With RPO LMG--The fuel alcohol content is less than 87 percent.

Circuit/System Verification
Review the Inspection/Maintenance (I/M) System Status indicators with a scan tool. All I/M System Status indicators should report YES.

Inspection/Maintenance (I/M) System Set Procedure
Important: Whenever the ignition is turned ON, ignition positive voltage is supplied to the heated oxygen sensor (HO2S) heaters. After verifying the enable criteria, turn OFF the ignition for approximately 5 minutes to allow the sensors to cool before continuing with the test. Once the engine is started, do NOT turn the engine OFF for the remaining portion of the set procedure.

  1. Ensure that the vehicle meets the conditions for a cold start listed above.
    ⇒ If the evaporative emission (EVAP) I/M System Status indicator displays NO, perform the EVAP Service bay test if available.
    ⇒ If the EVAP Service bay test is NOT available, it may take up to 6 drive cycles, with up to 17 hours between drive cycles, for the EVAP I/M System Status indicator to transition to YES.
    ⇒ If the O2S Heater System Status indicator displays NO, ensure that the ignition has been turned OFF for at least 10 hours.
  2. Set the vehicle parking brake and ensure the vehicle is in park for automatic transmission or neutral for manual transmission.
  3. Turn OFF all accessories; HVAC system, other electrical loads, including aftermarket/add-on equipment, etc.
  4. Start and idle the engine for at least 2 minutes and until 65°C (149°F) is achieved.
  5. Run the engine for 6.5 minutes within the following conditions:
    • MAF parameter between 4-30 g/s
    • Engine speed steady between 1000-3000 RPM
  6. Return the engine to idle for 1 minute.
  7. Apply and hold brake pedal, and shift to Drive for automatic, or apply clutch pedal for manual and operate the vehicle within the following conditions for 2 minutes:
    • Depress the accelerator pedal until TP Sensor angle is more than 2 percent.
    • MAF signal between 15-30 g/s
    • RPM steady between 1200-2000 RPM

    Important
    : Do NOT touch the accelerator pedal during the idle period. A change in TP Sensor angle or an increase in engine speed may invalidate this portion of the test.
  8. Release the accelerator pedal and shift the vehicle to Park for automatic, or Neutral and release clutch pedal for manual, and allow the engine to idle for 2 minutes.
  9. Quickly depress the accelerator pedal until TP Sensor Angle is more than 8 percent and return to idle, repeat 3 times.
  10. Allow engine to idle for at least 2 minutes.
  11. Release the parking brake and drive vehicle at 24 km/h (15 mph) or slower for 2 minutes.
  12. Continue to drive the vehicle for at least 5.5 miles between 45-112 km/h (28-70 mph) with the vehicle reaching at least 80 km/h (50 mph).
  13. Release the accelerator pedal for at least 2 seconds. This will allow the vehicle to enter decel fuel cut-off.
  14. Depress the accelerator pedal until the TP Sensor angle is increased 3-20 percent and maintain a safe speed for 1 minute.
  15. Safely stop the vehicle, with the engine in drive for automatic or in neutral with the clutch pedal depressed and parking brake applied for manual, idle for 2 minutes.
  16. Shift to Park for automatic and apply the parking brake, or neutral and release clutch pedal for manual.

    Important: Do NOT disturb the vehicle or turn ON the ignition until told to do so. Disturbing the vehicle may invalidate this portion of the test.

  17. Turn OFF the ignition and exit the vehicle. Do NOT disturb the vehicle for 45 minutes.
  18. Observe the Inspection/Maintenance (I/M) System Status with a scan tool. All of the I/M System Status indicators should display YES.

    ⇒ If the EVAP I/M System Status indicator displays NO turn OFF the ignition for 17 hours, ensure that the vehicle meets the conditions for a cold start, and repeat steps 12-18 six more times, or until the EVAP I/M System Status indicator transitions to YES. If the indicator continues to display NO, refer to the Inspection/Maintenance (I/M) System DTC Table to identify the DTCs that did not run. Follow the Conditions for Running the DTC in order to set the EVAP I/M System Status indicator

    ⇒ If any of the I/M System Status indicators display NO, refer to the Inspection/Maintenance (I/M) System DTC Table for the indicator which did not display YES. The I/M System DTC Table identifies the DTCs associated with each I/M System Status Indicator. Follow the Conditions for Running the DTC in order to set the associated status indicator.
 

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Discussion Starter #4 (Edited)
EVAP monitor procedure

<..deleted..>

⇒ If the EVAP I/M System Status indicator displays NO turn OFF the ignition for 17 hours, ensure that the vehicle meets the conditions for a cold start, and repeat steps 12-18 six more times, or until the EVAP I/M System Status indicator transitions to YES.
OMG....17h and repeat steps 6 more times or until EVAP transition to YES????? Unbelievable!!!!!!!!!!!!!!!!!!! I'm just curious, i have to sleep in the car on the shoulder of the highway to satisfy 17h, cold start and step 12: Continue to drive the vehicle for at least 5.5 miles between 45-112 km/h (28-70 mph) with the vehicle reaching at least 80 km/h (50 mph).


we must get someone who designed this stupid procedure and get him to do this a few times....
CRAP...

when I have some spare time, I will get some Arduino Board, and plug it in between all the sensors and ECM to make the ECM believe all of this has happened including driving and so on...

this is designed so we buy a new vehicle and do not have to deal with emission tests...
 

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Here is the GM drive cycle. If you do it right you will check off every single monitor and it takes 15 minutes. I've personally reset the OBDII readiness on my 05 GTO and then done this drive cycle and verified it hits every one.
http://www.obdii.com/drivecycle.html
Takes about 25 minutes for me because there's a perfect highway to do it about 10 minutes from my house. Just have to go at a time there's no traffic.
 
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