Diagnostic Routine B

Diagnostic Routine B

Diagnostic Overview

No Power in ACC - Vehicles with an Ignition Switch

Refer to Wiring Diagram Set 13 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

When in ACC mode, the BCM (Body Control Module) module provides ground for the coil (control) side of the RUN/ACC relay located in the BCM (Body Control Module). The RUN/ACC relay receives voltage from BCM (Body Control Module) fuse 10 (10A). The RUN/ACC relay is serviced with the BCM (Body Control Module).

The BCM (Body Control Module) also provides a ground circuit for the coil side of the accessory delay relay located in the BCM (Body Control Module). The accessory delay relay can be serviced separately from the BCM (Body Control Module).

Visual Inspection and Diagnostic Pre-checks

Make sure BCM (Body Control Module) fuse 10 (10A) is OK.

Pinpoint Test

1. CHECK FOR ACC VOLTAGE AT THE BCM (Body Control Module)

1. Disconnect: BCM (Body Control Module) C2280B.

2. Ignition ACC.

3. Measure:





Is the voltage greater than 11 volts?








2. CHECK THE IGNITION ACC CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Disconnect: Ignition Switch.

3. Measure:





Is the resistance less than 3 ohms?








3. CHECK FOR POWER TO THE RUN/ACC RELAY

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) fuse 10 (10A).

3. Measure:





Is the voltage greater than 11 volts?








4. CHECK THE ACCESSORY DELAY RELAY

1. Disconnect: Accessory Delay Relay.

2. Carry out the appropriate relay component test.

Does the relay pass the test?








5. CHECK FOR CORRECT BCM (Body Control Module) OPERATION

1. Disconnect and inspect all BCM (Body Control Module) connectors.

2. Repair:

- corrosion (install new connector or terminal - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

3. Reconnect the BCM (Body Control Module) connectors and all previously disconnected exterior system connectors. Make sure they seat and latch correctly.

4. Install BCM (Body Control Module) fuse 10 (15A) (if previously removed).

5. Operate the system and determine if the concern is still present.

Is the concern still present?