2014 GMC Sierra Electrical glitches

[sirtwig]

Just wanted to share my experience and hopefully avoid anyone else having to spend the time and money trying to diagnose this.

 

My truck is a 2014 sierra 1500 Base (WT), Canadian version (so the headlights are programmed to always be on, cannot be turned off)

 

The issues started with a traction control error message, then escalated to include;

 

Theft deterrent system error

TPMS error

Stabilitrak system error

Severe delay with Transmission shift indicator displaying what gear was selected (PRNDM)

Gauges all dropping to zero and resetting (intermittent at first, only on start up. then constantly whilst driving)

Small change in sensitivity of throttle pedal and steering

Transmission shifts felt a little inconsistent 

 

 

code reader was throwing the following codes;

 

B1395 - Device voltage reference output #1 circuit malfunction

B2580 - Headlamp High Beam control circuit malfunction

B2750 - Horn relay coil circuit malfunction

B3125 - LF Door only unlock circuit malfunction

B3130 - All door unlock circuit malfunction

B3135 - All door lock circuit malfunction

 

C0800 - ABS Device power #1 (low current #1) circuit malfunction

 

 

I started off by going through all ground connections (including G218), then replacing ground chassis to engine strap, battery negative cables with current sensor, new battery (old battery ended up needing replaced anyway), checked all fuses and electrical connections. None of this fixed the issue. 

Eventually after lots of research I decided to replace the BCM and have it reprogrammed at GMC...unfortunately this also didn't fix the problem. So back to the forums to spend hours looking for anyone else with any of these symptoms or anything even remotely similar. I stumbled across someone who had had their LED headlight bulbs cause an issue (different from what I was experiencing, but it got me thinking it might be worth a try), so I decided to disconnect the headlights (Canadian version, headlights can only be turned off by unplugging them), low and behold the truck ran great! no more error messages! 

 

So I replace the LED bulbs with halogen and this seems to have solved all issues!

 

Seems absolutely ridiculous that all these systems can be thrown off by some worn out resistors in the LED bulbs. when the bulbs were first installed I had no issues, for over a year. Truck had also had 2 other sets of LED bulbs installed prior to that with no issues.