Left Front Door Module

B1803 - Driver Door Lock/Unlock Switch Circuit Stuck Lock






For a complete wiring diagram, refer to.

• When Monitored: Continuously.

• Set Condition: If the (D903) Lin Bus circuit at the Driver Door Lock Switch does not change from low to high for over 30 seconds, this code will set.






Test Step 1 - TEST FOR INTERMITTENT CONDITION

• Turn the ignition on.

• With the scan tool, erase all DTCs.

• Operate the Driver Window/Door Lock Switch in the lock and unlock position several times.

• Cycle the ignition from on to off 3 times.

• Turn the ignition on.

• With the scan tool, read the DTCs.

Does the scan tool display this DTC?

Yes

• Go to Test Step 2

No

• The condition that caused this symptom is currently not present. Check for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched, and partially broken wires. Also, inspect the related connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals. Repair as necessary.

• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

Test Step 2 - CHECK (D903) LIN BUS CIRCUIT VOLTAGE







• Turn the ignition off.

• Disconnect the Driver Window/Door Lock Switch harness connector.

• Turn the ignition on.

• Measure the voltage between the (D903) Lin Bus circuit and ground at the Driver Window/Door Lock Switch connector.

• If the vehicle is equipped with Power Sliding Doors, D903 will be in cavity 3. If it does not have Power Sliding Doors, D903 will be in cavity 6.

Is the voltage above 9 volts?

Yes

• Replace Driver Window/Door Lock Switch.

• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

No

• Go to Test Step 3

Test Step 3 - CHECK (D903) LIN BUS CIRCUIT FOR A SHORT TO GROUND







• Turn the ignition off.

• Disconnect the Driver Door Module C5 harness connector.

• Measure the resistance between ground and the (D903) Lin Bus circuit.

Is the resistance above 10k ohms?

Yes

• Replace the Driver Door Module (DDM).

• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

No

• Repair the (D903) Lin Bus circuit for a short to ground.

• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior