2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2791

2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2791

瀚慖f the cooling fans are inoperative in any of the commanded states, refer to Cooling Fan Inoperative (without HP2) (See: Engine,

Cooling and Exhaust/Cooling System/Testing and Inspection/Symptom Related Diagnostic Procedures/Cooling Fan Inoperative)Cooling

Fan Inoperative (with HP2) (See: Engine, Cooling and Exhaust/Cooling System/Testing and Inspection/Symptom Related Diagnostic

Procedures/Cooling Fan Inoperative).

Circuit/System Testing

1. Test the thermostat for correct operation. Refer to Thermostat Diagnosis (See: Engine, Cooling and Exhaust/Cooling System/Testing and

Inspection/Symptom Related Diagnostic Procedures/Thermostat Diagnosis).

2. Test the engine cooling system for overheating. Refer to Engine Overheating (See: Engine, Cooling and Exhaust/Cooling System/Testing

and Inspection/Symptom Related Diagnostic Procedures/Engine Overheating).

3. Inspect the water pump and coolant flow for correct operation. Refer to Water Pump Replacement (See: Engine, Cooling and

Exhaust/Cooling System/Water Pump/Service and Repair).

4. Inspect the engine for worn/leaking/cracked cylinder heads and engine block. Refer to Coolant in Combustion Chamber (See: Engine,

Cooling and Exhaust/Engine/Testing and Inspection/Symptom Related Diagnostic Procedures/Coolant in Combustion Chamber) and Coolant

in Engine Oil (See: Engine, Cooling and Exhaust/Engine/Testing and Inspection/Symptom Related Diagnostic Procedures/Coolant in

Engine Oil).

Repair Instructions

Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.

P1380

DTC P1380 or P1381

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.