For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Passenger Door Handle Switch Signal | B1474 02 | 1 | 1 | --
Left Rear Door Handle Switch Signal | B1534 02 | 1 | 1 | --
Right Rear Door Handle Switch Signal | B1534 02 | 1 | 1 | --
Passenger Door Handle Switch Ground | -- | 1 | 1 | --
Left Rear Door Handle Switch Ground | -- | 1 | 1 | --
Right Rear Door Handle Switch Ground | -- | 1 | 1 | --
1. Power Door Latch Malfunction

### Circuit/System Description

When any exterior door handle is lifted, switched ground signals are sent to the remote control door lock receiver through the door handle switch signal circuits. If the status of the door lock system is Unlock, the power door latches will electrically release after lifting the exterior door handle. If the status of the door lock system is Lock, one of the following inputs will be required before the latch will release.

• | A door unlock switch activation

• | A door key cylinder unlock switch activation

• | An active keyless entry unlock command

• | A passive keyless entry unlock command message is received by the remote control door lock receiver

Once the enable criteria has been met, the remote control door lock receiver will supply power and ground to the door latch motor control circuits and the door will release.

### Diagnostic Aids

Note: Using the power door unlock switch or manually unlocking the doors does not disable the content theft deterrent arm mode. Also, disconnecting the battery or pulling fuses does not disable the arm mode, since the body control module (BCM) stores the content theft deterrent mode status in memory.

### Reference Information

#### Schematic Reference

Door Lock/Indicator Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Power Door Locks Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Ignition ON, command the scan tool Driver Door PEPS Release and Passenger Door PEPS Release to Lock and Unlock, the doors should perform the Lock and Unlock command from both commands.

⇒ | If any door latch is inoperative, refer to Power Door Latch Malfunction.

2. With the doors unlocked, open the all the doors by using their respective exterior door handles. The doors should release and open when using the exterior door handles.

⇒ | If any door does not release, refer to Exterior Door Handle Switch Malfunction.

• | Driver Door Handle Malfunction

• | Passenger Door Handle Malfunction

• | Rear Door Handle Malfunction

### Circuit/System Testing

#### Door Latch Malfunction

1. Ignition OFF, disconnect the harness connector at the appropriate door latch.
2. Ignition ON, connect a test lamp between the door unlatch control high circuit listed and ground.

• | A23D Door Latch Assembly - Driver terminal 10

• | A23P Door Latch Assembly - Passenger terminal 5

• | A23LR Door Latch Assembly - Left Rear terminal 10

• | A23RR Door Latch Assembly - Right Rear terminal 5

⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the K77 Remote Control Door Lock Receiver.

3. Connect a test lamp between the door unlatch control low circuit listed and ground.

• | A23D Door Latch Assembly - Driver terminal 5

• | A23P Door Latch Assembly - Passenger terminal 10

• | A23LR Door Latch Assembly - Left Rear terminal 5

• | A23RR Door Latch Assembly - Right Rear terminal 10

⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the K77 Remote Control Door Lock Receiver.

4. Test for less than 30 Ω between the door unlatch high and low control circuit terminals listed.

• | A23D Door Latch Assembly - Driver terminal 10 and 5

• | A23P Door Latch Assembly - Passenger terminal 5 and 10

• | A23LR Door Latch Assembly - Left Rear terminal 10 and 5

• | A23RR Door Latch Assembly - Right Rear terminal 5 and 10

⇒ | If greater than the specified range, test the door unlatch high and low control circuits for an open/high resistance. If both circuits test normal, replace the K77 Remote Control Door Lock Receiver.

5. If all circuits test normal, test or replace the door latch.

#### Exterior Door Handle Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the appropriate door handle switch.
2. Test for less than 10 Ω between the ground circuit terminal 1 and ground:

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, test for greater than 10 V between the signal circuit terminal 1 and ground.

⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, door control module.

4. Ignition ON, verify the following scan tool parameter is Inactive.

• | Exterior Driver Door Handle Switch

• | Exterior Passenger Door Handle Switch

• | Exterior Left Rear Door Handle Switch

• | Exterior Right Rear Door Handle Switch

⇒ | If not the specified value, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the K77 Remote Control Door Lock Receiver.

5. Connect the a 3 A jumper harness between the signal circuit terminal 2 and ground. Verify the following scan tool parameter is Active.

• | Exterior Driver Door Handle Switch

• | Exterior Passenger Door Handle Switch

• | Exterior Left Rear Door Handle Switch

• | Exterior Right Rear Door Handle Switch

⇒ | If not the specified value, test the signal circuit terminal 2 for a open/high resistance. If the circuit tests normal, replace the K77 Remote Control Door Lock Receiver.

6. If all circuits test normal, test or replace the exterior door handle switch.

### Component Testing

#### Exterior Door Handle Switch Test

1. Ignition OFF, disconnect the harness connector at the appropriate exterior door handle switch.
2. With the switch in the open position, test for infinite resistance between the signal terminal 2 and the ground terminal 1.

⇒ | If not the specified value, replace the exterior door handle switch.

3. With the switch in the closed position, test for less than 1 Ω between the signal terminal 2 and the ground terminal 1

⇒ | If greater than the specified range, replace the exterior door handle switch.

#### Door Latch Assembly Test

1. Ignition OFF, disconnect the harness connector at the appropriate door latch.
2. Ignition ON, install a 15 amp fused jumper wire between the control terminal listed below and 12 volts:

• | Driver door latch control terminal 10

• | Passenger door latch control terminal 5

• | Left rear door latch control terminal 10

• | Right rear door latch control terminal 5

3. Momentarily install a jumper wire between the control terminal listed below and ground. The door latch should perform the Unlock function:

• | Driver door latch control terminal 5

• | Passenger door latch control terminal 10

• | Left rear door latch control terminal 5

• | Right rear door latch control terminal 10

⇒ | If the function does not perform as specified, replace the door latch.

4. Reverse the jumper wires; the door latch assembly should perform the Lock function.

⇒ | If the function does not perform as specified, replace the door latch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Relay Replacement

• | Front Side Door Outside Handle Replacement

• | LINK 150844

• | LINK 150845

• | Control Module References for BCM, DDM, PDM, or RCDLR replacement, setup, and programming