For 1990-2009 cars

### Circuit Description

The powertrain control module (PCM) receives rough road information from the electronic brake control module (EBCM)/electronic brake and traction control module (EBTCM) on the 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/EBTCM transmits rough road information based on inputs from the wheel speed sensors. If the EBCM/EBTCM detects a condition which will not allow it to properly identify rough road situations while a misfire condition is being detected by the PCM, DTC P1380 will be set.

### Conditions for Running the DTC

• | The engine load is less than 87 percent.

• | The engine speed is less than 5000 RPM.

• | The vehicle speed is greater than 16 km/h (10 mph).

• | A misfire diagnostic trouble code (DTC) is occurring and is requesting the malfunction indicator lamp (MIL) to be illuminated.

### Conditions for Setting the DTC

The PCM has detected a EBCM/EBTCM rough road sensing error.

### Action Taken When the DTC Sets

• | The control module stores the DTC information into memory when the diagnostic runs and fails.

• | The malfunction indicator lamp (MIL) will not illuminate.

• | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.

• | The driver information center, if equipped, may display a message.

### Conditions for Clearing the DTC

• | A current DTC Last Test Failed clears when the diagnostic runs and passes.

• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.

• | Clear the DTC with a scan tool.

### Diagnostic Aids

DTC P1380 set indicates that the antilock brake system (ABS) has detected a malfunction which will not allow the EBCM/EBTCM to transmit correct rough road data to the PCM. Refer to Diagnostic System Check - ABS in Antilock Brake Systems.

Step | Action | Yes | No
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Schematic Reference: Engine Controls Schematics
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Diagnostic System Check - ABS in Antilock Brake Systems | Go to Diagnostic System Check - Engine Controls