AUTO 4WD button stays lit up.... ???

[LabRat116]

I have a 99 Blazer with the Auto Trac 236 transfer case.

I just installed a new (4) button controller switch in the dash this afternoon.

The AUTO 4WD button is staying lit up even in all the other modes (2HI, 4HI, 4LO).

What's keeping the AUTO 4WD button to stay lit up ??

[MT-2500]

Originally Posted by LabRat116

I have a 99 Blazer with the Auto Trac 236 transfer case.

I just installed a new (4) button controller switch in the dash this afternoon.

The AUTO 4WD button is staying lit up even in all the other modes (2HI, 4HI, 4LO).

What's keeping the AUTO 4WD button to stay lit up ??

Why did you replace switch?
Was old and new switcyh doing the same thing?
Have you checked the transfer case module for codes?
Any engine or transmission or body or ABS codes codes?
Post back any and all codes no?

[LabRat116]

Originally Posted by MT-2500

Why did you replace switch?
Was old and new switch doing the same thing?
Have you checked the transfer case module for codes?
Any engine or transmission or body or ABS codes codes?
Post back any and all codes no?

Thanks for your reply.

I had the Codes pulled and it showed a B2725 which indicates a malfunctioning switch.

I replaced the switch with a new one and the problems (as well as the B2725) remained.

I ended up replacing the Transfer Case Control Module a couple days ago with a used unit (same #) and it fixed the problem.

I've read the a bad TCCM will give erroneous/false Codes when they go bad. Also, the TCCM's in late 90s early 00 GM 4x4s are known to go bad quite frequently as well.