2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2569

2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 2569

ECM

DTC P0641 or P0651

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 P0641

- 5-Volt Reference 1 Circuit

DTC P0651

- 5-Volt Reference 2 Circuit

Circuit/System Description

The engine control module (ECM) has 2 internal 5-volt reference circuits. Each internal reference circuit provides 5-volt reference to more than one

sensor. Therefore, a short to ground or short to voltage on one external 5-volt reference circuit will affect the other components connected to the

same internal reference circuit.

Conditions for Running the DTC

* The ignition is in Run or Crank.

* The ignition voltage is greater than 6.0 V.

* The reduced engine power is Inactive.

* DTCs P0641 and P0651 run continuously when the above conditions are met.

Conditions for Setting the DTC

The ECM detects the 5-volt reference is out of range for less than 1 s.

Action Taken When the DTC Sets

DTCs P0641 and P0651 are Type A DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0641 and P0651 are Type A DTCs.

Diagnostic Aids

* The 5-volt reference 1 circuit provides 5 V to the following sensors:

- Manifold absolute pressure (MAP) sensor

- Fuel tank pressure (FTP) sensor

- Accelerator pedal position (APP) sensor 2

- Engine oil pressure (EOP) sensor

- Air conditioning (A/C) refrigerant pressure sensor

- Camshaft position sensor

- Barometric pressure (BARO) sensor

* The 5-volt reference 2 circuit provides 5 V to the following sensors:

- APP sensor 1

- Throttle position sensor 1 and 2

- Crankshaft position sensor

* It may be possible to locate the fault by disconnecting one component at a time from the affected 5-volt reference circuit while viewing the

5-Volt Reference Circuit Status parameter on the scan tool. The scan tool parameter will change from Fault to OK when the source of the

fault is disconnected. If all 5-volt reference components have been disconnected and a fault is still indicated, the fault may exist in the wiring