No 4hi (ok I'm begging for help here)

green02crew · Post by **green02crew** » Tue Dec 18, 2007 4:59 pm

I've checked out a couple threads and the sticky on this.
The problem I have is described at the posts I made at the bottom of the sticky.
Transfercase Codes
I'm making an appointment tomorrow to bring it in and have it looked at with my mechanic friend. I just want to see if I can get a few ideas on what to look at for issues. I've basically narrowed it down to 4 thoughts:
1) Most likely a bad encoder motor
2) Bad vacuum line?
3) Bad TCCM giving faulty readings
4) Bad dash switch
I have pretty much ruled out the last two as the problem has been reported twice by the TCCM. The switch seems to be operating just fine. Those two as well as a bad vacuum line were options given on the ZR2 forum. Any ideas so I can point in what direction to look at as well as a possible fix? If it is the motor could a junkyard find be sufficient? What costs are most likely associated here?

Sorry about freaking out but it is winter time and they don't plow much in my area along with two winter storms heading our way this week! I would hate to putt around in 4lo all day and watch my (imaginary) gas gauge drop. More like I would fill up at 100 miles rather than 200 since it always reads empty and low fuel. But thats just another recurring issue that to me, is not worth fixing because that is why I have a trip!

JaVeRo · Post by **JaVeRo** » Tue Dec 18, 2007 6:35 pm

(Assuming it's the 233 tranfer case, 3 button)

If it is an intermittent problem with the encoder motor, the contol module will only allow 2Hi and 4Lo after enough errors are detected. To erase the memory, pull fuse #8, Ctsy Lp, for 60 seconds or more. This won't fix your problem but may get you out of a jam until it is fixed.

Dorman makes an aftermarket encoder motor for about half the price of the GM.

James

green02crew · Post by **green02crew** » Tue Dec 18, 2007 7:11 pm

Yes it is the standard 3 button stock that came on the cc. Ok fuse #8 that is a huuuuge help! unplugging the battery is just a hassle every time. Where is this aftermarket encoder motor available?

JaVeRo · Post by **JaVeRo** » Wed Dec 19, 2007 9:03 am

Your local parts store may be able to get it.
Or you can try this:

link't long url-HJ

The jury is still out as far as the quality of this part. I put one on my wife's truck and it lasted 6 months. It was still under warranty and they shipped me another one with a return shipping tag for the old one. Didn't cost me a penny for the repacement.

James

green02crew · Post by **green02crew** » Wed Dec 19, 2007 8:50 pm

Thats not as bad a price as I had figured. Pulling the fuse and resetting it is an easy temp. solution. Could this be avoided if I use the 4wd more often or is it just bound to happen?

JaVeRo · Post by **JaVeRo** » Thu Dec 20, 2007 5:31 am

JUST MY OPINION, it seem to be more difficult for the motor to successfully shift if you are sitting still or if you are moving and have torque applied to the wheels.

When I know the motor is getting weak, I try to get the truck moving about 5mph, shift to neutral push the 4HI button while the truck is coasting, then shift back to Drive after the tranfer case shift is complete.

James