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
