Refer to Antilock Brake System Schematics in Antilock Brake Systems.
Circuit Description
The PCM receives rough road information from the EBCM/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 proper identification of rough road situations while a misfire condition is being detected by the PCM, DTC P1380 will be set.
Conditions for Running the DTC
| • | Engine load is less than 87.5 percent. |
| • | Engine speed is less than 5000 RPM. |
| • | Vehicle speed is more than 16 km/h (10 mph). |
| • | A misfire DTC is occurring and requesting the 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 PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test has been run and failed. |
| • | The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic has run and passed. |
| • | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using a scan tool. |
Diagnostic Aids
DTC P1380 set indicates that the ABS system has detected a malfunction which will not allow the EBCM/EBTCM to transmit correct rough road data to the PCM. Diagnostic System Check - ABS in Antilock Brake Systems should be used to diagnose this condition.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On Board Diagnostic (OBD) System Check? | -- | Go to Diagnostic System Check - ABS in Antilock Brake Systems |
