System Description
The body control module (BCM) controls the inadvertent battery power rundown protection feature. The BCM de-energizes CKT 1393 approximately 10 minutes after the ignition switch is turned from the ACC or RUN position to the OFF or UNLOCK position.
The BCM restores the power after any of the following actions occurs:
| • | Turning the ignition switch from the OFF or UNLOCK position to the ACC or RUN position. |
| • | Removing the key from the ignition lock cylinder. |
| • | Opening any of the vehicle doors. |
| • | Turning the IP dimmer switch to the DOME position. |
| • | Turning on any interior (courtesy) lamp that is connected to CKT 1393. |
| • | The BCM receives a message in order to unlock the doors from the remote control door lock receiver (BCM type 3 or 4 only). |
| • | Unlocking a door using a key (BCM type 4 only). |
The inadvertent batter power rundown protection feature is mileage-sensitive. Vehicles with less than 15 total driven miles time out within 162-198 seconds.
Conditions for Setting the DTC
The BCM detects a short to B+ or ground in CKT 1393.
Action Taken When the DTC Sets
The BCM sets DTC 2.
The inadvertent battery power rundown protection feature is disabled when CKT 1393 is shorted to B+.
The interior (courtesy) lamps do not turn ON when CKT 1393 is shorted to ground.
Conditions for Clearing the DTC
A short to B+ or ground in CKT 1393 is no longer present.
After the repairs are completed, refer to Body Control Module Diagnostic Information
Diagnostic Aids
| • | Inspect for a short to B+ in CKT 1393. |
| • | Inspect for a short to ground in CKT 1393. |
| • | Disconnect C393 and C200. This action isolates portions of CKT 1393 and assists in tracing for an electrical short. |
| • | Perform the following test while moving wiring and connectors. This will often cause the malfunction to appear. |
BCM Input/Output Test Procedure
- Turn OFF the dimmer switch.
- Turn the ignition switch to the OFF position.
- Remove the MALL PGM fuse.
- Turn the ignition switch to the ACC position.
- Within 1 second, turn the ignition switch from the ACC position to the OFF position then back to the ACC position.
- Turn the IP dimmer switch to the DOME position.
The BCM sounds the chime a number of times equivalent to the BCM type installed on the vehicle.
The BCM will sound any DTCs stored.
The BCM enters the Input/Output test. There are 7 steps in the Input/Output test:
| • | Test 1 de-energizes CKT 1393 (protected courtesy lamp output). |
| • | Test 2 energizes CKT 1393. |
| • | Test 3 grounds CKT 690 (courtesy lamps control). |
| • | Test 4 energizes the theft deterrent relay for 1 second by grounding CKT 352 and turns on the headlamps (BCM type 4 only). |
| • | Test 5 energizes the horn relay for 25 ms by grounding CKT 28 and sounds the horn (BCM type 4 only). |
| • | Test 6 turns on the theft deterrent indicator lamp by grounding CKT 749 (BCM type 4 only). |
| • | Test 7 turns off the theft deterrent indicator lamp by opening CKT 749 (BCM type 4 only). |
The BCM completes the steps of the Input/Output test in numerical order.
In order to move to the next test, cycle the IP dimmer switch from DOME to OFF then back to DOME. The BCM sounds the chime a number equivalent to the Input/Output test number above. The Input/Output test sequence repeats until the ignition switch is turned to the OFF position.
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
-
Always perform the BCM diagnostic system check before attempting to diagnose this DTC.
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This step performs the BCM Input/Output test. This test energizes and de-energizes CKT 1393. During this test, the technician can monitor the courtesy lights. If the courtesy lights turn off during this test, CKT 1393 is in good condition and no short to B+ or ground is present.
-
This step checks for a short to B+ in CKT 1393.
-
This step checks for a short to ground in CKT 1393.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Was the BCM Diagnostic System check performed? | -- | Go to Step 2 | ||
Perform the BCM Input/Output test. Refer to Body Control Module Diagnostic Information . Do all lights connected to CKT 1393 turn off when the BCM Input/Output performs test 1 and turn on when performing test 2? | -- | Go to Step 5 | Go to Step 3 | |
Is the voltage less than the specified value? | 2 V | Go to Step 4 | Go to Step 6 | |
Is the resistance equal to the specified value? | OL (infinite) | Go to Step 8 | Go to Step 7 | |
5 | Malfunction is intermittent or not present at this time. Refer to Diagnostic Aids for more information. Is the action complete? | -- | Go to Step 9 | -- |
6 | Repair short to voltage in CKT 1393. is the repair complete? | -- | Go to Step 9 | -- |
7 | Repair short to ground in CKT 1393. Is the repair complete? | -- | Go to Step 9 | -- |
8 |
Is the repair complete? | -- | Go to Step 9 | -- |
9 |
Are there any BCM DTCs present? | -- | System OK |
