Vehicle: 2018 Chevy Traverse, FWD, V6-3.6L, Automatic Transmission/Transaxle

Mileage: 77,087 miles

Problem: The Traverse’s engine died while driving, and it was towed to the shop. When it got there, the engine started with no issues, but there was a host of electrical problems.

Case Details: The horn stayed on, so the technician quickly pulled the horn fuse. It stopped. The emergency flashers were also on but could not be shut off with the hazard switch. The windshield wipers and windshield washer pump ran anytime the engine was running or the battery was connected.

The technician disconnected the emergency flasher switch on the instrument panel and tried disconnecting the headlight switch, but the flashers kept flashing. At one point, reconnecting the emergency switch would lock and unlock the doors. Removing the body control module (BCM) fuses #1 and #2 got the flashers to stop. Another weird problem was that the wiggling steering wheel would also cause all the doors to lock/unlock.

On the plus side, the radio operated normally, and the A/C worked fine. With all the weird stuff happening, this was a perfect time to call ALLDATA Tech-Assist.

The Tech-Assist consultant said that with all the hot weather they’d been having lately, the customer had likely been using the A/C frequently. It’s possible that the BCM got wet due to poor drainage of the evaporator drain hose. Condensation can overflow the evaporator case and drip onto the BCM.

He suggested removing the passenger side center console cover that’s labelled with a fuse panel marker, squeezing the duct pipe out of the way to see the BCM, then removing the BCM to check for water damage.

When the technician removed the BCM, water poured out of it.

Confirmed Repair: There was some debris in the A/C evaporator drain, so the technician cleared it then dried out the electrical connector and made sure the pins were clean. After replacing the BCM, they sent the vehicle over to the Chevy dealer to have the BCM reprogrammed and the immobilizer reset. When the vehicle got back from the dealer, all the gremlins had been exercised. Problem solved!