I'm having a hard time pulling the code. I know HPT can't do it and I took it to a mechanic friend and his SnapOn tool said "ECU error".

Is this because of the tune? Do I need to get a replacement PCM?

Thanks in advance

 

Not sure about the tune influence. Maybe you could attack it from a different angle: logic.

When does it come on? Immediately after starting the truck, while it's still sitting still (module); or after it's been rolling for a few seconds (wheel sensor)?

You could just do the obvious, if you haven't already, and check to make sure it's all plugged in and such as that. Fuses all good etc.

If all that seems in order, and it's the situation where it immediately comes on, probably best to just change the module. AFAIK not much else can make it do that. They go bad quite a bit. It's not much fun but you can do it without disturbing the hydraulics.

 

I’ve done the obvious stuff like fuses and checking the fluid.

It’s consistently on from key on until key off. It happened a few weeks ago coming home from work on the interstate.

Wheel bearings are about 2 years old.

 

Yeah I suspected you probably had, just thought I should mention it.

Sounds like the module has defecated the sheets. You could try the parts cannon. Not too hard to find the modules at the buzzard nests.

 

Thanks. I’ll look at R&R’ing the unit.

 

Its not because of the tune. Which Snap on tool does he have?

 

Ive been fooling with AWD trucks for some time already and from personal experience its usually always its a bad Wheel bearing.
Check the ABS cable on the strut tower, ive seen them get disconnected, and even burned a cable on the header.
Also, the cheaper brand wheel bearings usually last about 2 years, give or take.

 

Thanks.

I'll double-check the connectors on the shock towers.

When I replaced the bearings 2 years ago, I used Timken.

 

Also in the colder months, ive had the lights come on as well when ive had low brake fluid in the reservoir.
Not sure what year yours is, but my NNBS has a small leak somewhere, very minute, but in the colder months it would get low and give me brake system/ABS lights.

 

Anything on the serial network can cause read, flash, or pulling code issues. Make sure you have 12 volts at the OB2 port as well.

Regarding the code - with the snap on scanner you should be able to read wheel speed from all the wheels. That will tell you if you have a bad sensor causing the issue. Need to fix the connection issue to do that though.