Diagnostic Instructions
DTC Descriptors
DTC P1380: Misfire Detected Rough-Road Data Not Available
DTC P1381: Misfire Detected No Communication With Brake Control Module
Circuit/System Description
The engine control module (ECM) detects engine misfire by detecting variations in crankshaft deceleration between firing strokes. For accurate detection of engine misfire, the ECM must distinguish between crankshaft deceleration caused by actual misfire
and deceleration caused by rough road conditions. The antilock brake system (ABS) can detect if the vehicle is on a rough road based on wheel acceleration/deceleration data supplied by the wheel speed sensor. If the ABS detects rough road above a predetermined
threshold, this information is sent to the ECM. The ECM uses the rough road information when calculating engine misfire. If the ABS is malfunctioning and cannot detect rough roads, the misfire diagnostic will continue to run. However, if an engine misfire DTC
sets, this DTC also sets indicating that rough road data was not available or there was no communication with the brake control module during the misfire calculation due to an ABS malfunction.
Conditions for Running the DTC
P1380
• | The vehicle speed is more than 0 km/h . |
• | DTC P1380 runs continuously once the above condition has been met. |
P1381
DTC P1381 runs continuously
Conditions for Setting the DTC
P1380
• | The ABS controller sends a message to the ECM indicating that a failure has occurred in the ABS module. |
P1381
• | An ABS malfunction exists, preventing the ECM from receiving rough road detection data. |
Action Taken When the DTC Sets
DTCs P1380 and P1381 are Type C DTCs.
Conditions for Clearing the DTC
DTCs P1380 and P1381 are Type C DTCs.
Reference Information
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Circuit/System Verification
- Monitor the ABS DTCs on the scan tool.
- Engine running, observe the DTC information with a scan tool. DTCs P1380 or P1381 should not set.
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame Records data.
- Engine running, observe the DTC information with a scan tool. DTCs P1380 or P1381 should not set.
- Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.