C1340 code with "center diff", "asc off", "asc track" light on (1 Viewer)

[zhloea]

Hi, read some posts about this in the forum, but all of those posts without a clear solution for it and all the people who have the same issue as mine seems just end up with nothing specific...

So I really hope someone can give me a way to try to fix this problem. thanks.

Story:
Yesterday, I accidentally hit the center diff lock button when I left Walmart, then I got "center diff", "vsc off", "vsc track" light on after about 5 mins driving, those lights went off after I restart the truck engine. I hooked the code reader and I got code "C1340 opn ckt in ctr diff lck signal ". But this code will always be there except I actively "eraser it" using a code reader.
Then I did some double-check
1. the center diff lock does work after I pushed the button, normally it come with "vsc off" light.
2. the center diff lock light and VSC off light does come off when I push the button again, and the center diff does disengage after that.
3. if only center diff light and VSC off light on, no code will be generated. But, sometime, VSC track light will come on after couple mins driving, I can feel the dragging from the rear of the truck at the moment all three lights on, then the C1340 code will be thrown.

I will try to replace the "Beck Arnley 201-1788 Back Up Lamp Switch", but seems this only works for some cases.

Could this be a normal thing?
because we are not supposed to turn on the center diff lock when drive on a normal road and the user menu did say we should turn off the central diff as soon as we get out of the special road situation.

Please let me what should try and any ideas, suggestions..Thanks!

 

[JunkCrzr89]

The Beck Arnley position switch won’t fix your problem. Does the VSC light come on during hard turns?

 

[zhloea]

The Beck Arnley position switch won’t fix your problem. Does the VSC light come on during hard turns?

It only comes up after the center diff lock button pressed. after press center diff button, then CDL and VSC-off on, then driving a little bit the VSC-track will on, then it will not disappear except restart, but the code will be generated even the lights off...

 

[zhloea]

The Beck Arnley position switch won’t fix your problem. Does the VSC light come on during hard turns?

Well, if I don't turn on the center diff and erase the code, it becomes a perfect working code-free truck... I ask here also for this: how big the issue here? still safe to drive? of course, I do want to fixed...

 

[JunkCrzr89]

Probably safe to drive, unless ABS is being randomly activated at a wheel. I think you’ll need to go thru the step-by-step diagnostic procedures for c1340 to resolve this issue. It’s an electrical issue for sure, but could be wiring, ECU, CDL switch, etc. problem.

 

[zhloea]

No abs, I bought this truck a year now, even only turn on and Off center diff without certain long time driving it will not throw the issue/code, that is why I did not tell this until yesterday

 

[zhloea]

Would that be a symtom of "0 point calibration" issue? I just replaced the steering rack, cv axles, control arms and rotors in last couple months...

 

[zhloea]

Probably safe to drive, unless ABS is being randomly activated at a wheel. I think you’ll need to go thru the step-by-step diagnostic procedures for c1340 to resolve this issue. It’s an electrical issue for sure, but could be wiring, ECU, CDL switch, etc. problem.

"ABS is being randomly activated at a wheel", I recently cleaned up both front-wheel sensors, but the rear wheels' abs sensor should be still dirty, will this be something I should check?

 

[JunkCrzr89]

Would that be a symtom of "0 point calibration" issue? I just replaced the steering rack, cv axles, control arms and rotors in last couple months...

Could be.

"ABS is being randomly activated at a wheel", I recently cleaned up both front-wheel sensors, but the rear wheels' abs sensor should be still dirty, will this be something I should check?

Possible but I think unlikely.

Again, I think you need to go thru the FSM’s diagnostic troubleshooting procedures for the code. That’s going to be the easiest way to figure out what’s wrong.