'01 Jimmy no 4Hi - What will the Service guys want to replace?

jsciarrjsciarr Member Posts: 3
edited March 2014 in GMC
Guys - new to forum - have an '01 Jimmy with 36K mi and rarely use 4wd. Have same ol' problem - 2WD fine, 4LO available (only while in Neutral), no 4HI at all. I do notice that backlight on the 3-button switch is dimmer for 4HI than (2HI and 4LO). Have pulled all the fuses(4WD, ATC), done the 5 key-switch on/off, lots of blinking, no joy. Assume I can't trace all the vac hoses, and instead, decide to take it to GMC Service shop. What are they going to sell me is the problem and the fix? Cause I know it's no $15 part replacement. You take it to them and it's $800-$1K before you leave the place. Can you give me any defenses to fight the Service Mgr. shpeal? Would really appreciate it.


  • repairdogrepairdog Member Posts: 948
    If a 3 button dash switch and np233 case yes it could be the dash switch, the encoder motor stepping twice bypassing 4Hi but why, the TCCM or computer connector, or the vac lines/3 port switch. If you get 4Lo the front axle coupler should be working - did it lock solid in 4Lo and actually be in it is the question. Dealer price for the TCCM and encoder motor are very high and you can get the prices on sites like rockauto and gmpartsdirect - shows dealer and theirs.
  • jsciarrjsciarr Member Posts: 3
    Thanks for the quick response - repairdog. Yes it does lock in 4Lo. I'm presuming the encoder motor works - since I can hear it engaging to 4Lo - 4Hi just does absolutely nothing. So, a switch I'm presuming I could replace myself - the TCCM and vac lines - i'll probably have to rely on a qualified service person. Would you agree that I should/could argue for not replacing the encoder motor - since it appears to be working. But gut tells me, they will say it all has to be replaced. Kind of really silly that 4x4 that has 36K and has been in 4WD less than a dozen times needs to be fixed. Again - thanks for the feedback.
  • jsciarrjsciarr Member Posts: 3
    Just spent $100 to have them tell me it's the TCCM and it will be $722 to replace it. I've been trying to look-up the part to see if I can get it outside of this dealership and do it myself for less but can't find it. Any ideas? I've taken repairdog's advice and searched rockauto and gmpartsdirect and 1/2 dozen other sites - but can't put my hands on this part.
    Thanks again for the help.
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