Wrenchtech is right when he says the GM tech I scanner can aid greatly in this diagnostic, but here are things you can check:
1. Perform POWERTRAIN ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK, then go to next step. 2. Using scan tool, check for stored DTC(s). If DTC P0106, P0108, P0112, P0113, P0300, P0401, P0441, P1108, P1404, P1406, P1441, P1508, P1509 or P1645 is also present, diagnose affected DTC(s) first. If DTCs are not present or after diagnosing affected DTC(s), go to next step. 3. Check vacuum leaks at MAF sensor seal, throttle body spacer, intake manifold, PCV, EGR valve, plate or tubes and brake booster and hoses. Repair as necessary and retest. If air leak is not found, go to next step. 4. Check for stuck or incorrect PCV valve. Check for air (unmetered) leaks at oil dipstick tube or oil filler cap. Repair as necessary and retest. If vacuum leak is not found, go to next step. 5. Using FREEZE FRAME and FAILURE RECORDS data function on scan tool, duplicate conditions under which DTC P0101 was set. If DTC resets, go to next step. If DTC does not reset, see DIAGNOSTIC AIDS. 6. Go to DTC P0106 and perform diagnostic test, then return to this step. If repairs were necessary, verify repairs and retest. If repairs were not necessary, go to next step. 7. Replace MAF sensor and retest.
Friday, September 24th, 2010 AT 9:31 PM