Sunday, December 22, 2019

2010 Cadillac Truck Escalade AWD V8-6.2L Page 2535

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System

Check - Vehicle) prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an

overview of the diagnostic approach.

* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure

Instructions) provide an overview of each diagnostic category.

DTC Descriptors

DTC P1380

- 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

Note: If an UXXXX DTCs are set, diagnose those first.

1. Engine idling, observe the EBCM DTC information with a scan tool. EBCM DTCs should not set.

锟斤拷If a DTC sets, refer to Diagnostic Trouble Code (DTC) List - Vehicle (See: Diagnostic Trouble Code Descriptions/Diagnostic Trouble

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