2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2793
- Misfire Detected - Rough Road Data Not Available
DTC P1381
- Misfire Detected - No Communication with Brake Control Module
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 sensors. If the ABS detects rough road above 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
* The vehicle speed is greater than 8 km/h (5 mph).
* The engine speed is less than 8,192 RPM.
* The engine load is less than 60 percent.
* Engine misfire is detected and DTC P0300 sets with the MIL illuminated.
* DTCs P1380 and P1381 run continuously when the above conditions are met.
Conditions for Setting the DTC
P1380
* The electronic brake control module (EBCM) sends a message to the ECM indicating that a failure has occurred in the EBCM.
* Engine misfire is detected and DTC P0300 sets with the MIL illuminated.
P1381
* An EBCM malfunction exists for more than 10 s, preventing the ECM from receiving rough road detection data.
* Engine misfire is detected and DTC P0300 sets with the MIL illuminated.
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 (See: Diagnostic Trouble Code Descriptions/Powertrain Diagnostic Trouble Code
(DTC) Type Definitions)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description ( See: Hybrid Drive
Systems/Description and Operation/Hybrid Modes of Operation).
2. Ignition ON, verify the scan tool hood position parameter displays Open.
瀚慖f the hood position does not display Open, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code
Descriptions/Diagnostic Trouble Code (DTC) List - Vehicle) for DTC P254F.
Note: If an UXXXX DTCs are set, diagnose those first.
3. Engine idling, observe the EBCM DTC information with a scan tool. EBCM DTCs should not set.
瀚慖f a DTC sets, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic Trouble
Code (DTC) List - Vehicle) for further diagnosis.
瀚慖f there are no EBCM DTCs set, refer to the following:
* Symptoms - Antilock Brake System (See: Brakes and Traction Control/Antilock Brakes / Traction Control Systems/Testing and
Inspection/Symptom Related Diagnostic Procedures/Symptoms - Antilock Brake System) for the ABS - Hybrid
* Symptoms - Antilock Brake System (See: Brakes and Traction Control/Antilock Brakes / Traction Control Systems/Testing and
