GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 2003 🢒 Ascender - 4WD 🢒 DTC 🢒 DTC B1445

Circuit Description

The Body Control Module (BCM) supplies battery positive voltage/RAP supply voltage to the sunroof or the relay (relay equipped on the GMT370) that enable the sunroof & power rear quarter vent windows (if equipped). After the ignition is turned to the OFF position, It will remain operational for 10 minutes or until and door is open.

Conditions for Running the DTC

Battery voltage must be between 9-16.0 volts.

Conditions for Setting the DTC

The RAP (relay if equipped) supply voltage circuit is low.

Action Taken When the DTC Sets
    • The DTC will be current for as long as the fault is present.
    • Any function/system, which is RAP output enabled, will be disabled for as long as the fault is current. Refer to Retained Accessory Power (RAP) Schematics to see what is powered in RAP power mode.

Conditions for Clearing the DTC
    • The DTC status will change from current to history when the fault is no longer present.
    • A history DTC may be cleared using a scan tool clear DTCs feature.
    • A history DTC will be cleared after 100 error free ignition cycles.

Step

Action

Yes

No

Schematic Reference: Retained Accessory Power (RAP) Schematics

1

Did you perform the Power Sunroof System Diagnostic System Check?

Go to Step 2

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2
  1. Turn ON the ignition, with the engine OFF.
  2. Attempt to operate the power sunroof system and the rear power quarter vent windows (if equipped).

Do the functions above normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3
  1. Turn OFF the ignition.
  2. Disconnect the Ribbon Connector/C3 that contains the RAP supply voltage circuit.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp between B+ and the RAP supply voltage circuit (pin A12) at the BCM harness connector.

Does the test lamp illuminate?

Go to Step 4

Go to Step 6

4

Test the RAP supply voltage circuit short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 5

5

Replace the RAP relay.

Did you complete the repair?

Go to Step 7

Go to Step 5

6

Important: Replace the body control module and perform the set up procedure. Refer to Body Control Module Replacement and to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Did you complete the repair?

Go to Step 7

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7
  1. Use the scan tool in order to clear the DTCs .
  2. Operate the system in order to verify the repair.

Does the DTC reset?

Go to Step 2

System OK