4wd service codes

[More Power]

The most frequent cause of the sort of problems you're seeing is the pushbutton switch panel. I had the same problem, and simply replaced the switch panel with a new one. Solved the problem... and the local dealer parts guys said they replace them quite often. Mine was replaced about 3 years ago, and it's still working fine. It was about $40 if I remember correctly.

On another note, my wife's AWD Chevy Tahoe also had problems with its 4WD indicator system. Again, I simply replaced the switch panel.. Problem solved.

Jim

[h45wt]

The most frequent cause of the sort of problems you're seeing is the pushbutton switch panel. I had the same problem, and simply replaced the switch panel with a new one. Solved the problem... and the local dealer parts guys said they replace them quite often. Mine was replaced about 3 years ago, and it's still working fine. It was about $40 if I remember correctly.

On another note, my wife's AWD Chevy Tahoe also had problems with its 4WD indicator system. Again, I simply replaced the switch panel.. Problem solved.

Jim

Jim,

Thanks for the info.

I pulled the 4wd fuse more than a week and hundreds of miles ago. I've had no more faulty indicators. The service 4wd light comes on every time I start the engine but that is understandable.

Would this argue that the fault is in the encoder or might it still be the switch unit? I would think that no faults while the fuse was out would point more to the encoder.

[DmaxMaverick]

I've seen few of these, as well as mine. The button cluster was the cure, each time. I know of one encoder motor failure, and there was no "Service 4wd" message, and no DTC. I'm not sure why there would be no message with the fuse pulled. Never tried that. I'll pull my fuse to see if the message appears (no 4x4 issues at this time), and get back later.

[h45wt]

I guess I spoke too soon. 4wd fuse still out and today backing out of parking space I felt/heard a thump. No bodies or debris behind or underneath truck. A few miles later saw the 4wd low light flashing. Restart no change. Pressed 2wd button and 4wd low light went on solid, 2wd started blinking. After 2 restarts no chg but ck eng light on. New dtc p0700 tcm malf. tried to reset but would not erase. After a few more restarts I was able to clear the p0700 and the ck end light went out. all looks normal now except for the service 4wd msg at each restart probably due to the fuse being pulled. Don't know what the thump was, perhaps transfer case or drive line. I guess this latest symptom would argue for the switch panel failure. Unless something else pops up I'll get a new one when I get home. Any hints on steps to replace it?

[DmaxMaverick]

Easy to replace....

Tilt wheel all the way down, set the E-brake, and move gear selector to 1 (they get in the way if you don't). Pop off the IP bezel. It's one piece from the far left to the right of the radio/HVAC. Just pull it gently from edges you can get a grip on (with fingertips, starting at the radio corner area), all the way around until it's free (pull only enough to free the clips, not too far). The switch cluster has friction tabs holding it in (and maybe a screw, I don't remember, but it should be obvious), just engage them with a finger or screwdriver and pull the switch out. Unplug. Reverse for install.

Same procedure for all the in-dash switches and accessories (headlamp switch, radio, HVAC head, etc.). Very simple.

If for any reason a bezel clip tab doesn't lock in solid (and creates a rattle/squeak), wrap the tab with one or two layers of scotch tape, depending on how loose (it doesn't take much). It will snug it up just right. If you bend a tab, reinstall it bent, if at all possible. Bending them back usually breaks them off.