• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Interior Lamp Control Circuit | -- | -- | B2558 01 | |
BCM | -- | -- | B2558 01 |
When the headlamp switch is turned to the HEADLAMPS or Parking Lamps position, the body control (BCM) applies battery positive voltage to the instrument panel (I/P) courtesy lamps. When a door is opened, the door latch assembly applies a ground to the BCM. The BCM supplies battery positive voltage to the courtesy lamp supply voltage circuit and applies a ground to the courtesy lamps low control circuit.
• | The interior lights are commanded ON by the BCM. |
• | At least one door is open. |
The interior lamp control circuit is shorted to B+ voltage for 1 second.
The BCM disables the interior lamp control output for the remainder of the ignition cycle.
• | A current DTC B2558 clears when the BCM no longer detects a short to battery positive voltage in the control circuit on the interior lamp circuit. |
• | 100 consecutive ignition cycles have been recorded without the DTC being detected. |
• | Using a scan tool can clear the DTC. |
• | If the DTC is a history DTC, the problem may be intermittent. Refer to Testing for Intermittent Conditions and Poor Connections . |
• | The following conditions may cause an intermittent malfunction to occur: |
- | An intermittent in the courtesy lamp low control circuit. |
- | The BCM is intermittently shorted to battery positive voltage. |
Master Electrical Component List
Ignition ON, engine OFF, turn the I/P dimmer switch to the door position, with a Scan Tool Command the Interior Lamps ON and OFF. The footwell and courtesy lamps should turn ON and OFF.
⇒ | If the test lamp does not illuminate, test the Courtesy Lamp Low Control circuit signal terminal C3 pin 11 of the BCM for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the signal circuit BCM terminal C3 pin 11 for a short to ground. |
⇒ | If not the specified value, test the signal circuit terminal BCM C3 pin 11 for a short to voltage. If the circuit tests normal, replace the BCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for BCM replacement, setup and programming