Circuit Description
Circuit 356 from the body control module (BCM) controls the driver door unlock relay. When the BCM receives a driver door unlock signal, the BCM supplies battery voltage to the relay. Ground for the relay is supplied by circuit 150.
Conditions for Running the DTC
The battery voltage supplied to the BCM is within the normal operating range (aproximately 9-16 volts).
Conditions for Setting the DTC
CKT 356 is shorted to battery positive voltage for .2 seconds.
Action Taken When the DTC Sets
The BCM disables the driver door unlock output for the remainder of the ignition cycle.
Conditions for Clearing the DTC
| • | A current DTC B3128 will clear when the malfunction is no longer present and the ignition switch is cycled. |
| • | All BCM history codes clear after 100 ignition cycles (from OFF to ON) with no current codes active during the 100 ignition cycles. |
Diagnostic Aids
If the DTC is a history DTC, the problem may be intermittent. Perform the tests while wiggling the wiring and connectors. This will often cause the malfunction to appear.
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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Listen for an audible click when the driver door unlock relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
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Verifies that the body control module is providing voltage to the driver door unlock relay.
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Tests for an open in the ground circuit to the driver door unlock relay.
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Tests if voltage is constantly being applied to the driver door unlock relay.
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Power Door Systems Diagnostic System Check? | Go to Step 2 | |
Does the driver door unlock relay turn ON and OFF with each command? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 | |
Does the test lamp turn ON and OFF with each command? | Go to Step 4 | Go to Step 5 | |
Does the test lamp turn ON and OFF with each command? | Go to Step 8 | Go to Step 10 | |
Does the test lamp remain illuminated with each command? | Go to Step 7 | Go to Step 6 | |
6 | Test the control circuit of the driver door unlock relay for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
7 | Test the control circuit of the driver door unlock relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
8 | Inspect for poor connections at the driver 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 13 | Go to Step 11 |
9 | Inspect for poor connections at the harness connector of the body control module. 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 13 | Go to Step 12 |
10 | Repair the ground circuit of the driver door unlock relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 13 | -- |
11 | Replace the driver door unlock relay. Did you complete the replacement? | Go to Step 13 | -- |
12 | Replace the body control module. Refer to Body Control Module Replacement Important: Perform the set up procedure for the body control module. Refer to Body Control Module (BCM) Programming/RPO Configuration Did you complete the replacement? | Go to Step 13 | -- |
13 |
Does the DTC reset? | Go to Step 2 | System OK |
