| Subject: | SES Light due to P0420 DTC on Low Mileage Vehicles - Update ECM Calibration |
| Models: | 2006 Chevrolet Cobalt |
| 2006 Pontiac Pursuit (Canada Only) |
| with 2.2L Engine (VIN F - RPO L61) |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
On rare occasions, a SES light may be encountered on low mileage vehicles due to a P0420 DTC. This may also occur shortly after catalytic converter replacement regardless of vehicle mileage. As mentioned in the P0420 diagnosis in SI, a new catalytic
converter with less than 100 miles on it may set a P0420 due to out-gassing of the internal matting.
Recommendation/Instructions:
If this concern is encountered, recalibrate the ECM with the latest calibration. At this time, the latest calibration is titled "new calibration with diagnostic enhancements for DTC P0315". This calibration was released on CD 11, which was shipped to
dealers during November 2005. This calibration, or any that follow, are designed to address this concern
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
