2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 451

2010 Cadillac Truck Escalade RWD V8-6.0L Hybrid Page 451

瀚慖f greater than 1 ohm, repair the circuit for open/high resistance

7. Test for infinite resistance between the ignition key resistor signal circuit terminal 4 of the BCM and ground.

瀚慖f less than specified, repair the signal circuit for a short to ground.

8. If all circuits test normal, replace the BCM.

Component Testing

Ignition Switch

1. Ignition OFF, disconnect the harness connector at the ignition switch.

2. Using the Resistance Test table below, check the resistance between the terminals of the ignition switch listed in each switch position.

If any reading is not as specified, replace the ignition switch.

Repair Instructions

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

* Control Module References (See: Testing and Inspection/Programming and Relearning) for BCM replacement, setup, and programming

* Ignition and Start Switch Replacement (See: Powertrain Management/Ignition System/Sensors and Switches - Ignition System/Ignition

Switch/Service and Repair)

B1441

DTC B1441

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) provides an overview of each diagnostic category.

DTC Descriptors

DTC B1441 01

- Device Ignition OFF, RUN, and CRANK Circuit Short to Battery

DTC B1441 06

- Device Ignition OFF, RUN, and CRANK Circuit Short to Ground or Open

Diagnostic Fault Information

Circuit/System Description

This vehicles power mode master (PMM) is the body control module (BCM). The ignition switch is a low current switch with multiple discrete

ignition switch signals to the PMM for determination of the power mode. The PMM receives the ignition switch signals, and additionally a

reference voltage signal from the BCM, through the ignition switch, and back to the BCM. There are redundancies within the PMM system that can

allow operation of certain subsystems when there are faults in the ignition switch circuits. Other information such as serial data input from other

modules and DTCs is also used to determine what power mode signals and information is transmitted by the PMM. The BCM logic uses all this