Check Engine Light (MIL) Illuminated, Usually without Driveability Symptoms, DTCs P0128, P0604, P0326, P0420, P0717, P2431 Set on L61 Engine (Follow SI-If Necessary, Reprogram ECM with New Calibration
| Subject: | Check Engine Light (MIL) Illuminated, Usually without Driveability Symptoms, DTCs P0128, P0604, P0326, P0420, P0717, P2431 Set on L61 Engine (Follow SI, and If Necessary, Reprogram Engine Control Module (ECM) with New Service Calibration) |
| Models: | 2006 Chevrolet Cobalt, HHR |
| 2006 Pontiac Pursuit (Canada Only) |
| 2006 Saturn ION |
| with Ecotec 2.2L 4-Cylinder Engine (VIN D, F -- RPO L61) |
| Built Prior to Following VIN Breakpoints: |
Model | VIN Breakpoint |
|---|---|
Chevrolet Cobalt | 67707283 |
Chevrolet HHR | 6S559494 |
Pontiac Pursuit (Canada Only) | 67707283 |
Saturn ION | 6Z152773 |
Condition
Some customers may comment that the " Check Engine Light" malfunction indicator lamp (MIL) is illuminated. Technicians may find the following DTCs may have set false failures. Typically, the vehicle will exhibit no driveability symptoms, only the MIL with one or more of the above mentioned DTCs.
The following are the DTC descriptors and the description of the false failure concern:
| • | DTC P0128 Engine Coolant Temperature (ECT) below thermostat regulating temperature -- The DTC may set due to a calibrated time parameter or under extremely cold conditions. |
| • | DTC P0604 ECM Random Access Memory (RAM) -- The DTC may set under low voltage conditions. |
| • | DTC P0326 Knock Sensor (KS) Performance -- The KS signal indicates an engine knock is present and the ECM command spark retard at a given engine load and speed is more than the calibrated value. |
| Important: A new catalyst may fail this test within the first 200 miles of operation due to out-gassing of the internal matting. If this occurs, operate the vehicle at highway speeds for approximately 1 hour, then retest. |
| • | DTC P0420 Catalyst System Low Efficiency -- The ECM has determined the catalyst efficiency has degraded below a calibrated threshold. The ECM may prematurely diagnose a catalyst failure before the catalyst has been allowed to run hot enough for a sufficient amount of time to burn off manufacturing coatings inside the converter. These coatings adversely affect the catalyst efficiency and the O2 sensor performance. |
| • | DTC P0717 Input Speed Sensor Circuit Low Voltage -- The transmission turbine speed sensor may set due to a calibrated rpm and time parameter. This fault may set falsely, especially if the engine is stalled and the vehicle is moving, or if the key is cycled on-off-on while the vehicle is moving. |
| • | DTC P2431 Secondary Air Injection System Pressure Sensor A Circuit Range/Performance -- The control module determines that the difference between the AIR pressure sensor and the barometric pressure (BARO) sensor signals is greater than 10 kPa when the AIR pump is commanded OFF or the control module determines that the difference between the AIR pressure sensor and the BARO sensor signals is greater than 50 kPa when the AIR pump is commanded ON. The DTC may set due to the ignition key ON and the engine OFF but the engine is still turning. |
Cause
Engineering has identified a concern with the ECM software.
Correction
Important: The vehicle may or may not exhibit any driveability symptoms. If there are any driveability symptoms along with any DTCs mentioned in this bulletin, DO NOT reprogram the ECM. Follow Service Information (SI) first.
Reprogram the ECM with the latest calibrations if the above concerns are encountered. An updated ECM calibration is now available to address this concern. This calibration, or any that follow, is designed to address this concern. Refer to Service Programming System (SPS) using the appropriate Service Information (SI) procedures. The new ECM calibrations will be available to dealerships as part of TIS2000 incremental satellite update version 12, which was broadcast to dealers on 11/28/2005. For the dealerships that use CDs, they were mailed on 12/07/2005. As always, make sure your Tech 2® is updated with the latest software version.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
J6354 | Module, Powertrain Control - Engine Reprogramming | Use Published Labor Operation Time |
