Electrical- no crank, no start

CASEY MIGUEL

MEMBER
2010 CHEVROLET SUBURBAN
5.3L
V8
4WD
AUTOMATIC
225,000 MILES

History: I replaced the suspension pump just prior to the trip. Also, the vehicle was used to jump another and the polarity on the cables was switched for a hot second.

While on a trip across the country (approximately 1,600 miles one way) my car suddenly freaked out, while driving down the freeway the door locks started cycling, cluster gauges were jumping around, service stabilitrack, service suspension system messages were displayed, ac started blowing hot air, and the transmission was stuck in one gear.

I pulled off the highway to a gas station and turned off the vehicle. Attempted to restart with no crank and no start. Occasionally it would start then die after 10 seconds or so. No communication with the ECU.

Had the vehicle towed to a repair shop just down the road. They said I needed a new fuse box due to corrosion. I had that replaced and the vehicle started and ran for a test drive. No codes. I picked up the vehicle and drove about five miles away and it did it again. I returned to the shop. They said it would take time to diagnose. After a long few days with no answers I finally got word that they think it’s my abs module. When they unplug it the vehicle starts and runs. I paid to have that replaced but when they attempted to program it they couldn’t communicate.

I cut my losses after a week and took it to a dealership. The dealership tells me my suspension control module and body control module are bad. Plus I have like 10 volts running thru my system when it’s supposedly supposed to be 3-4v.

They are replacing my modules and will retest. My question is, why might there be high voltage? Can a bad module short allow a surge of power to ruin other modules? Did the jump possibly have something to do with this and how do you correct that? It could it be the suspension pump? Thanks in advance!

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

I assume that they are saying the 3-4 volts is supposed to be the GMLAN system. This is similar to the CAN bus networks that are covered in this guide:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

What it sounds like is one of the terminating resistor modules is faulty which could have happened when the cables were reversed only if the cables were hooked to the other vehicle correctly.

The only way to solve this is to replace this module that is effected so if they found the BCM and suspension module are the issue then that would be what needs replaced.

Unfortunately it does not take long to damage the circuit boards on these modules as there is no circuit protection on the ground side. So the circuit board is what burns up first.

The odd thing though is there is normally codes. However, if they could not communicate with any of the modules then that is due to the entire network being down. So if they found 10 volts then that explains that part.

Did they give the reasoning for wanting to replace these modules?

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