Remote Start fuse/module? Electrical Gremlins.

[m1dn]

Seem to be having all sorts of electrical gremlins that only appear in winter.

Periodically when i remote start the car, it sometimes starts and then goes into electrical what the hell mode and sometimes doesn’t remote start and goes in said mode.

When it goes into this “wtf” mode, it wont crank, all electronics work and all gauges go crazy up n down dance.
Nothing helps for about 30min period and even OBD can’t connect.

Then 30min later it starts like a champ, with few lights on that i reset and it drives like a champ again.
Seems to happen ONLY during remote start and very occasionally.

Errors when this happen persist on basically every single module all related to can-bus connection issues trying to talk with previous module in chain:
U0073
U0140
U0101

Replaced:
- Ground cable
- Negative battery cable
- Positive to starter
- Battery

The only thing I haven’t touched yet is Main Fuse. ( No way main fuse would cause these right?! )

Wondering if anyone else has had similar issues or knows where to dig further?

 

[swathdiver]

Might be a BCM problem but I'm speculating. First thought is the battery but you replaced that already. Have you checked the underhood fuse box for corrosion?

 

[m1dn]

Might be a BCM problem but I'm speculating. First thought is the battery but you replaced that already. Have you checked the underhood fuse box for corrosion?

Pretty sure i did before, but going to check it from inside out and around it as well tomorrow

Also ordered the little big 125amp fuse, it looked sketchy and old, new one is only 20$ anyway

 

[mikez71]

Here is a TSB that covers those codes and shows several troublespots in the wiring...

https://static.nhtsa.gov/odi/tsbs/2012/SB-10043829-6448.pdf

just noticed you said ONLY on remote start...
Do you use your e-brake normally?

Swathdiver mentioned the BCM... which does contain remote start run time and other code and does control your guages.

 

[m1dn]

Here is a TSB that covers those codes and shows several troublespots in the wiring...

https://static.nhtsa.gov/odi/tsbs/2012/SB-10043829-6448.pdf

just noticed you said ONLY on remote start...
Do you use your e-brake normally?

Swathdiver mentioned the BCM... which does contain remote start run time and other code and does control your guages.

Oooh thank you! That’s a lot of gremlins haha.
Seems to match exactly my case.

It happened today as well without remote start after very cold night, few minutes and back to normal.

Going to place the big boi in garage next week when it warms up and start going through wiring in TSB, let’s see if i can find anything obvious.

Also waiting on main fuse, maybe that helps as well

 

[Joseph Garcia]

Have you checked your other grounds, like the one on the frame underneath between the firewall and the front driver's seat?

 

[m1dn]

Have you checked your other grounds, like the one on the frame underneath between the firewall and the front driver's seat?

Firewall yes, had no idea there is one under drivers seat ha, thanks!
Is it inside the cabin and actually under the seat or it’s under the truck?

Going to check that one today

 

[Joseph Garcia]

Firewall yes, had no idea there is one under drivers seat ha, thanks!
Is it inside the cabin and actually under the seat or it’s under the truck?

Going to check that one today

Under the truck. It is one of the main ground points.

 

[j91z28d1]

for can issues it seems to be worth a check on the rear module for air ride or. mag ride if you have them. seems salty roads and it back under the truck don't go well together

 

[m1dn]

Cleaned the shit out of main fuses connections, nuts and found the ground wire under driver seat as well as another ground with similar mount further back at passenger door. Both cleaned down to metal, they were pretty rusted and covered in salt.

Let's see if that helps!