Diagnostic Aids (Except LeSabre)
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 Pontiac Grand Prix, 2003 Pontiac Bonneville, 2003 Chevrolet Monte Carlo, 2003 Chevrolet Impala, and 2003 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
Check for the following conditions:
- PCM will not enable catalyst test until the following conditions are met:
- Engine speed is within 200 RPM from desired idle.
- Throttle Position (TP) is 1.5 percent or less.
- Short term integrator is -20-20 percent.
- Catalyst test will abort if vehicle conditions fall outside conditions listed below while test is running:
- Engine speed is within 200 RPM from desired idle.
- Throttle Position (TP) is 1.5 percent or less.
- Short term integrator is -20 to 20 percent.
- The catalyst test may abort due to a change in the engine load. If this condition occurs, use the scan tool on order to force the cooling fans ON. Repeat this set.
- The number of attempted tests is limited to 18 per key cycle.
- More than 6 tests may have to be attempted in order to get 6 completed tests. An aborted test counts as an attempted test.
- If 18 tests have been attempted and if a decision has not been made during this key cycle, turn the key OFF for 30 seconds, start engine, and perform the conditions for running the DTC, including the 10-minute run time.
- After returning to an idle the HO2S 1 signal may stay rich or lean for several seconds, causing the test to be delayed.
NOTE:
When using scan tool to force cooling fans on, use NEXT LIST and PREVIOUS LIST soft keys to enter catalyst data list. If catalyst data list is not entered this way, cooling fan control will be canceled.