Circuit Description
The powertrain control module (PCM) receives rough road information from the EBCM on the Class 2 serial data circuit. The PCM uses the rough road information to enhance the misfire diagnostic by distinguishing crankshaft speed variations caused by driving on rough road surfaces from variations caused by true misfires. The EBCM transmits rough road information based on inputs from the wheel speed sensors. If the EBCM detects a condition which does not allow the EBCM to properly identify rough road situations while a misfire condition is being detected by the PCM, DTC P1380 is set.
Conditions for Running the DTC
| • | The engine load is less than 87%. |
| • | The engine speed is less than 5000 RPM. |
| • | The vehicle speed is more than 10 mph. |
| • | A misfire DTC is occurring and requesting that the malfunction indicator lamp (MIL) be illuminated. |
Conditions for Setting the DTC
The PCM has detected a EBCM rough road sensing error.
Action Taken When the DTC Sets
The PCM stores the conditions which were present when the DTC set as Fail Records data only.
Conditions for Clearing the MIL/DTC
| • | A history DTC clears after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC may be cleared using the scan tool Clear Info function or by disconnecting the PCM battery feed. |
Diagnostic Aids
A DTC P1380 set indicates that the ABS / TCS system has detected a malfunction which does not allow the EBCM to transmit correct rough road data to the PCM. The ABS/TCS Functional Test in ABS/TCS Diagnosis should be used to diagnose this condition.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to theABS/TCS Functional Test in ABS/TCS System |
