Malfunction Indicator Light (MIL) on with DTC P0446 Code Set (Reprogram PCM)
| Subject: | Malfunction Indicator Lamp (MIL) On With DTC P0446 Code Set (Reprogram PCM) |
| Models: | 1998-2000 Chevrolet and GMC C/K Models |
| with 7.4 L Engine (VIN J -- RPO L29) and California Emissions (NB6) |
Condition
Some customers may comment on a Malfunction Indicator Lamp (MIL) that is illuminated. Further investigation will find a DTC P0446 code has been set.
Cause
The code is more likely to occur with less than 1/2 tank of fuel. The VCM monitors the performance of the EVAP system by applying a predetermined level of vacuum to the EVAP system. The VCM then monitors the vacuum decay rate. The VCM sets this DTC if the vacuum decay rate is greater than a predetermined value. The decay rate at idle is higher than the monitoring portion of the current calibration range will allow.
Correction
Once the vent solenoid is verified to be operational, reprogram the vehicle with a new calibration.
Parts Information
The calibrations listed are electronic calibrations and are NOT available from GMSPO. Calibrations will be available from Techline starting on the TIS 2000 CD 13 shipped to dealers 7/6/00.
Model Year | Original Production Calibration Part Number | New Service Calibration Part Number |
|---|---|---|
1998 | 16250416 | 9388662 |
1998 | 16250419 | 9388663 |
1999 | 9351030 | 9388664 |
1999 | 9351033 | 9388665 |
2000 | 16259196 | 9388666 |
2000 | 16259199 | 9388667 |
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
J6355 | Prom - Reprogramming, On Car | Use Published Labor Time |
