Electrical Issues Due to Backup Lamps

Some 2017 Acadia (VIN N) and XT5 models may have several electrical issues, including a dead battery, an inoperative Stop/Start system, and instrument cluster and switch backlighting illumination conditions. These conditions may be due to the wrong bulbs installed in the backup lamps. (Fig. 1)

Fig. 1

On 2017 models, incandescent bulbs are used in the backup lamps. (Fig. 2) In some vehicles, LED lamps may have been installed instead. The Body Control Module (BCM) evaluates the Reverse Lamp circuit to determine bulb outages by applying and monitoring a low voltage signal. Since LED lamps have different electrical properties than incandescent bulbs, the circuit does not operate as expected. The BCM is calibrated for incandescent bulbs and, as a result, may stay awake after the key is off if LED lamps are used, causing the BCM to continuously monitor the circuit, which can lead to multiple electrical conditions.

Fig. 2

Check the backup lamps for the installation of the proper bulbs. If LED lamps (Fig. 3, #1) are found, they should be replaced with incandescent bulbs. (Fig. 3, #2)

Fig. 3

On XT5 models, the backup lamp assembly is underneath the rear fascia. (Fig. 4)

Fig. 4

On Acadia models, the backup lamp is part of the rear signal lamp assembly. (Fig. 5)

Fig. 5

 

– Thanks to Tom Burlingame

 

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