The body control module (BCM) controls the door unlock relay. Voltage is applied to the door unlock relay through the door unlock relay control circuit when the BCM senses a door unlock switch activation or a keyless entry unlock command.
Battery positive voltage is between 9 and 16 volts.
• | The BCM detects an open in the door unlock relay control. This condition must be present for more than 0.3 seconds. |
• | The BCM detects a short to ground in the door unlock relay control while commanding the door unlock relay. This condition must be present for more than 0.3 seconds. |
• | The door unlock relay will be inoperative. |
• | The BCM stores either DTC B3132 or DTC B31233 in memory. |
• | A history DTC will clear after 100 consecutive fault free ignition cycles. |
• | A scan tool may be used to clear the DTC. |
• | The following conditions may cause the DTC to set: |
- | An open or short to ground in the door unlock relay control circuit |
- | The a faulty door unlock relay |
- | The BCM is shorted to ground internally. |
• | If the DTC's are a history DTC, the fault may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
The numbers below refer to the step numbers on the diagnostic table.
Listen for an audible noise when the door unlock relay is commanded. Command the door locks to lock and unlock. Repeat the commands as necessary.
Verifies that the BCM is providing voltage to the door unlock relay.
Tests for an open in the door unlock relay ground circuit.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Door Lock/Indicator Schematics Connector End View Reference: Power Door Systems Connector End Views | |||
1 | Did you perform the Diagnostic System Check for the door systems? | Go to Step 2 | |
Does the door unlock relay energize when commanded? | Go to Diagnostic Aids | Go to Step 3 | |
Does the test lamp flash when the door unlock relay is commanded ON? | Go to Step 4 | Go to Step 5 | |
Connect a test lamp between the door unlock relay ground circuit and battery positive voltage. Does the test lamp illuminate? | Go to Step 7 | Go to Step 8 | |
5 | Test for an open or short to ground in the door unlock relay control circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 6 |
6 | Inspect for poor connections at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 9 |
7 | Inspect for poor connections at the door unlock relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 10 |
8 | Repair open in the door unlock relay ground circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 12 | -- |
9 |
Did you complete the replacement? | Go to Step 12 | -- |
10 | Replace the door unlock relay. Did you complete the replacement? | Go to Step 12 | -- |
12 |
Does the DTC reset? | Go to Step 2 | System OK |