Electrical Problems

imiller1974 · May 16, 2020

My truck broke down today. Coming home from a kayaking trip, I had to serve pretty hard around a car. I slammed on the brakes, and jerked the steering wheel hard to avoid a collision. I got a chrismas tree on the dash... Service Stabilitrak came on, reduced steering assist, service 4wd system, tach stopped working, oil pressure gauge, volt gauge, coolant gauge all went to low. The radiator fans went to 100% on, no check engine light, at that point though. Pulled over, popped hood and looked around. Shut the truck off, started back up, same problems, almost no power steering. Shut back off, won't restart. Got it towed home and started looking things over. Disconnected the battery for 30 mins. Checked fuses, checked relays, checked the BCM plugs, checked as many grounds as I could find. Now throwing a check engine light, UO100 code, fuel gauge went to low, even though I have a half tank... It says CAL beside the odometer now, instead of the compass. What Now?

Edited May 16, 2020 by imiller1974

JimCost2014 · May 16, 2020

2 minutes ago, imiller1974 said:

My truck broke down today. Coming home from a kayaking trip, I had to serve pretty hard around a car. I slammed on the brakes, and jerked the steering wheel hard to avoid a collision. I got a chrismas tree on the dash... Service Stabilitrak came on, reduced steering assist, service 4wd system, tach stopped working, oil pressure gauge, volt gauge, coolant gauge all went to low. The radiator fans went to 100% on, no check engine light, at that point though. Pulled over, popped hood and looked around. Shut the truck off, started back up, same problems, almost no power steering. Shut back off, won't restart. Got it towed home and started looking things over. Checked fuses, checked relays, checked the BCM plugs, checked as many grounds as I could find. Now throwing a check engine light, UO100 code, fuel gauge went to low, even though I have a half tank... It says CAL beside the odometer now, instead of the compass. What Now?

Any idea how old your battery is?

imiller1974 · May 16, 2020

5 yrs old, on the charger now, even though, I doubt thats the issue...

JimCost2014 · May 16, 2020

1 minute ago, imiller1974 said:

5 yrs old, on the charger now, even though, I doubt thats the issue...

When they fail, they will cause all kind of problems, I would plan on replacing it.

If is the factory one, you got your moneys worth out of it.

Bash74 · May 16, 2020

If you don't have the ability to test all modules then just get it to the dealer or someone who can. You just have a loss of comms to a module. Could be battery issue but who knows at this point.

Sent from my SM-G975U1 using Tapatalk

imiller1974 · May 17, 2020

14 minutes ago, Bash74 said:

If you don't have the ability to test all modules then just get it to the dealer or someone who can. You just have a loss of comms to a module. Could be battery issue but who knows at this point.

Sent from my SM-G975U1 using Tapatalk

I agree, I have a charger on the battery, up to 12.8 volts, it's not the problem. I've lost coms to a module(s)/ ECU. calling a dealer Monday morning to get it towed there. I've done everything I know how to do...

ftwhite · May 17, 2020

Check your grounds. Might have ripped one lose it the hard stop/turn. These trucks act crazy when they get lose/bad grounds. Just a thought.

snailtrax · May 17, 2020

16 hours ago, imiller1974 said:

I agree, I have a charger on the battery, up to 12.8 volts, it's not the problem. I've lost coms to a module(s)/ ECU. calling a dealer Monday morning to get it towed there. I've done everything I know how to do...

12.8 on the charger is not good enough. You need to charge the battery with at least a 10 amp charger, fully overnight at 13.3 to 13.6 and then pull off surface charge with the headlights for a few minutes. Let it rest a few more minutes, then test voltage. Might be a little low, say 12.4 to 12.5. Let it sit overnight while disconnected. Should be 12.6 or 12.7 . I pick up used batteries at work all the time. If they have been out there for a couple days and show 12.6, it's still good. You need at least a 10 amp charger.

imiller1974 · May 17, 2020

1 hour ago, snailtrax said:

12.8 on the charger is not good enough. You need to charge the battery with at least a 10 amp charger, fully overnight at 13.3 to 13.6 and then pull off surface charge with the headlights for a few minutes. Let it rest a few more minutes, then test voltage. Might be a little low, say 12.4 to 12.5. Let it sit overnight while disconnected. Should be 12.6 or 12.7 . I pick up used batteries at work all the time. If they have been out there for a couple days and show 12.6, it's still good. You need at least a 10 amp charger.

Brand new, fully charged battery put on today, no change. It wasn't a problem with the battery.

All grounds have been tested, that I could find.