Diagnostic Routine B

Diagnostic Routine B

Diagnostic Overview

A Single or More Than One Door Lock Is Inoperative

Refer to Wiring Diagram Set 110 for schematic and connector information Electrical Diagrams.

Normal Operations and Fault Conditions

The BCM (Body Control Module) supplies voltage to the lock all relay, the unlock driver door relay or unlock all relay based upon input from the door lock control switch or the RKE (Remote Keyless Entry) transmitters. Upon a lock request, the BCM (Body Control Module) supplies voltage on the all door lock circuit and ground on the driver and passenger door unlock circuits. Upon an unlock request, the voltage and ground are reversed on the previously listed circuits. When the door lock and unlock relays are not energized, they are connected to ground.

NOTE: The lock all, unlock driver door, and the unlock all relays are internal to the BCM (Body Control Module) and are non-serviceable.

Visual Inspection and Diagnostic Pre-checks

- Inspect BCM (Body Control Module) fuses:
- F66 (20A)
- F70 (20A)
- F83 (20A)
- F84 (20A)

Special Tool(s)






Pinpoint Test

NOTICE: The following Pinpoint Test uses a test light to simulate normal circuit loads. Use only the test lamp recommended in the Special Tools table at the beginning of this system or electrical equivalent. To avoid connector terminal damage, use the Rotunda Flex Probe kit for the test light probe connection to the vehicle. Do not use the test lamp probe directly on any connector.

1. CHECK THE OPERATION OF THE DRIVER DOOR LOCK

1. Press the LOCK and UNLOCK buttons on a RKE (Remote Keyless Entry) transmitter while observing the driver door lock.

Does the driver door lock operate in only one direction?






2. CHECK THE OPERATION OF THE PASSENGER DOOR LOCKS

1. Press the LOCK and UNLOCK buttons on a RKE (Remote Keyless Entry) transmitter while observing all 3 passenger door locks.

Are all 3 passenger door locks inoperative?






3. CHECK THE PASSENGER DOOR UNLOCK OUTPUT CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) C2280E.

3. Disconnect: RH (Right Hand) Front Door Latch.

4. Measure:





Is the resistance less than 3 ohms?






4. CHECK THE LOCK OUTPUT CIRCUIT FOR VOLTAGE

NOTE: The BCM (Body Control Module) only supplies voltage to the actuator momentarily. It is important to monitor the test light while pressing LOCK on a RKE (Remote Keyless Entry) transmitter.

1. Disconnect: Inoperative Door Lock Actuator.

2. For the driver side doors, press LOCK on a RKE (Remote Keyless Entry) transmitter while monitoring the test light.





3. For the passenger side doors, press LOCK on a RKE (Remote Keyless Entry) transmitter while monitoring the test light.





Does the test light momentarily illuminate?






5. CHECK THE UNLOCK OUTPUT CIRCUIT FOR VOLTAGE

NOTE: The BCM (Body Control Module) only supplies voltage to the actuator momentarily. It is important to monitor the test light while pressing UNLOCK on a RKE (Remote Keyless Entry) transmitter.

1. For the driver side doors, press UNLOCK on a RKE (Remote Keyless Entry) transmitter while monitoring the test light.





2. For the passenger side doors, press UNLOCK on a RKE (Remote Keyless Entry) transmitter while monitoring the test light.





Does the test light momentarily illuminate?






6. CHECK THE DRIVER DOOR UNLOCK OUTPUT CIRCUIT FOR AN OPEN

1. Ignition OFF.

2. Disconnect: BCM (Body Control Module) C2280E.

3. Measure:





Is the resistance less than 3 ohms?






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

1. Ignition OFF.

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

3. Repair:

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

4. Reconnect all the BCM (Body Control Module) connectors and make sure they seat and latch correctly.

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

Is the concern still present?