Circuit Description
The BCM operates the interior lamps using the delayed interior lamps (DIL) relay and the interior lamp relay. When the DIL relay is energized, the relay provides battery power to the coil of the interior lamp relay. Upon receiving various inputs, the BCM commands the interior lamps ON by energizing the interior lamp relay at terminal C13. When the relay is energized, the relay provides a ground path for the interior lamps.
Conditions for Setting the DTC
The BCM monitors the output to the interior lamps relay every second at terminal C13. The fault code is set only when the DIL relay is active, a DTC B1971 is not set and the feedback doesn't match the commanded state for 2 seconds (open circuit, short to B+ or ground).
Action Taken When the DTC Sets
| • | The BCM continues to command the requested state until the state is achieved or until the state changes. |
| • | Stores a DTC B2471 in the BCM memory. The problem may intermittent if the DTC is a history DTC. |
Conditions for Clearing the DTC
| • | The conditions for the fault are no longer present. |
| • | Use a scan tool. |
| • | A history DTC will clear after 50 ignition cycles if the condition for the fault is no longer present. |
Diagnostic Aids
Check for the following conditions if a history DTC is indicated:
| • | A damaged wiring harness. Inspect the wiring harness for damage. If the wiring harness appears to be in good condition, observe the display on the DMM while moving the connectors and wiring harnesses related to the circuits. A change in the DMM display during this test will indicate the location of the fault. |
| • | For additional information, refer to Intermittents and Poor Connections Diagnosis |
Test Description
The following numbers refer to the step numbers on the diagnostic table:
-
This step uses a scan tool to test the interior lamp operation and to verify if the fault is present.
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This step tests for an intermittent condition in the circuits that can cause a DTC B2471 to set.
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After verifying that no circuit problems exist and the multifunction relay is OK, the BCM is most likely at fault. The BCM needs to be programmed after installation.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the BCM System Check? | -- | Go to Step 2 | |
Did the interior lamps light when commanded ON? | -- | Go to Step 3 | Go to Step 4 | |
Were any repairs made? | -- | Go to Step 12 | -- | |
4 |
Is the measured voltage at the specified value? | B+ | Go to Step 5 | Go to Step 6 |
5 |
Is the voltage at terminal C13 less than the specified value? | 1 V | Go to Step 11 | Go to Step 10 |
6 |
Was an open found in CKT™XY801? | -- | Go to Step 8 | Go to Step 7 |
7 | Measure the resistance from BCM connector C2 terminal C13 (CKT XY801) to a good ground. Is the measured resistance at the specified value? | OL | Go to Step 13 | Go to Step 9 |
8 | Locate and repair the open circuit in CKT XY801. Is the repair complete? | -- | Go to Step 12 | -- |
9 | Locate and repair the short to ground in CKT XY801. Is the repair complete? | -- | Go to Step 12 | -- |
10 | Locate and repair the short to B+ in CKT XY801. Is the repair complete? | -- | Go to Step 12 | -- |
|
Important: Perform the set up procedure for the BCM. Replace the BCM. Refer to Body Control Module Replacement . Is the replacement complete? | -- | Go to Step 12 | -- | |
12 |
Did a current DTC B2471 set? | -- | Go to Step 2 | System OK |
13 | Replace the multifunction relay. Is the replacement complete? | -- | Go to Step 12 | -- |
