Circuit Description
The BCM interfaces with the vehicle's power distribution system through the RAP relay. The RAP relay allows the BCM to control the application of power to the feed circuits to the sunroof and the power windows. When the ignition switch is in either the ACC or the RUN position, the BCM energizes the RAP relay by applying battery voltage to the RAP relay control circuit.
The BCM turns off the RAP relay when the ignition switch is in the START position. The RAP feature therefore disables during engine cranking.
When the ignition switch turns from ON or ACC to LOCK or OFF, with all of the vehicle doors closed, the BCM leaves the RAP relay energized for 10 minutes, or until any vehicle door opens and the BCM detects a ground signal in one of the door ajar circuits.
Conditions for Setting the DTC
| • | The BCM detects no voltage at the RAP relay control circuit when the BCM is trying to energize the RAP relay. |
| • | The above condition must be present for more than 300 milliseconds. |
Action Taken When the DTC Sets
| • | The BCM stores DTC B1477 in memory. |
| • | The RAP relay powered functions will not operate. |
| • | The circuits powered by the RAP relay will never be powered if the relay control circuit is open. |
Conditions for Clearing the DTC
| • | A current DTC clears when the malfunction is no longer present. |
| • | A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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Listen for an audible click when the RAP relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
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Verifies that the BCM is providing voltage to RAP relay.
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Tests for an open in the ground circuit to the RAP relay.
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Tests if voltage is constantly being applied to the RAP relay.
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Retained Accessory Power (RAP) Diagnostic System Check? | Go to Step 2 | |
Does the RAP 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 RAP relay for a short to ground. 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 RAP 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 RAP 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 (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 13 | Go to Step 12 |
10 | Repair the ground circuit of the RAP relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 13 | -- |
11 | Replace the RAP relay. Did you complete the replacement? | Go to Step 13 | -- |
12 |
Important: Perform the set up procedure for the body control module. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System. Replace the body control module (BCM). Refer to Body Control Module Replacement in Body Control System. Did you complete the replacement? | Go to Step 13 | -- |
13 |
Does the DTC reset? | Go to Step 2 | System OK |
