Diagnostic Aids (LeSabre Only)
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:
- the PCM will not enable the catalyst test until the following conditions are met:
- The engine speed is plus or minus 100 RPM from the desired idle.
- The Throttle Position (TP) is zero percent.
- The short term integrator is -20 percent and 20 percent.
- The catalyst test will abort if the vehicle falls outside the conditions listed above while the test is running.
- The catalyst test may abort due to a change in engine load, for example, from the A/C or from the coolant fan. If this condition occurs, use the scan tool in order to force the cooling fans ON, and return to step 2.
- More than 6 tests may have to be attempted in order to get 6 completed tests. An aborted test counts as an attempted test. The number of attempt tests is limited to 18 per key cycle. After returning to an idle the HO2S 1 signal may stay rich or lean for several seconds causing the test to be delayed.
- Faulty Connection At PCM
Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals. and poor terminal to wire connection. Use a corresponding mating terminals to test for correct terminal tension. - Damaged Harness
Inspect the wiring harness for damage. If the harness appears to be OK, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display will indicated the location of the fault.
NOTE:
When using the scan tool to force the cooling fans on use the next list and previous list soft keys to enter the catalyst data list. If the catalyst data list is not entered this way the cooling fan control will be canceled.