Dear Roadie, Mooseman, et al.:
I'm sure there's others too, but you 2 guys seem to have a good handle on the chevy trailblazer drivetrain, specifically the transfer case and attached encoder motor for a 2003 chevy trailblazer ext LT I6.
I am getting C0327 code, which seems to be indicating a bad or open ground from the encoder motor to?. The 4-Hi and 4-Lo will work when I first start the car up, but never the A-4WD (like it's not even there). After driving awhile, the "Service 4-WD" light comes on and cannot shift into or out of any of these modes at all. So even if I've cleared the C0327 code, it will then come back up at this point. If I shut the car off awhile, system resets and can go thru the above again. Also getting a Loss of Class-II Communication with ATC (code U1026) and No State of Health from Module (U1000) codes.
Started a new thread because all other info on this subject does no seem to apply to my situation of course (encoder motor works, proper wheel(s) spin, fuses are all good, proper actuator motors are making their noises, TCCM and Switch have been replaced already, etc.). This is a new problem within the last week as I've used the 4WD several times already this season and I thought I had it licked because there was a broken wire near where the encoder motor plugs in to the wiring harness (4-WD would not engage at all and only got buzzing at the encoder motor, though selector switch said I was in A-4WD no matter where the knob was, but I was only in 2-Hi in actuality) that I fixed by bypassing the plug and just tying the wires together (orange wire I believe) and the system worked completely as designed for 2 days.
Question is:
1.) Can I just run a new ground from the plug at the encoder motor (bypassing the plug, but will be spliced in to the encoder motor wiring of course)?
2.) If so, and assuming it's the solid black wire coming out of the encoder motor, where do I ground it too (chassis, direct to battery, etc.) to see if that will work?
3.) If not either of the above, what do I test with my multimeter to tell me which wire or wires are bad from the encoder motor as my scantool will give me P and C codes, but won't get more specific than that for diagnosis?
4.) Should I just replace the whole wiring harness if even possible and not ridiculously complicated?
5.) Am I way off on all this and I need to do something else?
Sorry for all the questions at once, but I can't seem to find anything on the internet that pertains to my exact problem and I figure one of you guys will know what's wrong if explained to you properly. Feel free to ask follow-up questions, but that about sums it up for now.
skobie
I'm sure there's others too, but you 2 guys seem to have a good handle on the chevy trailblazer drivetrain, specifically the transfer case and attached encoder motor for a 2003 chevy trailblazer ext LT I6.
I am getting C0327 code, which seems to be indicating a bad or open ground from the encoder motor to?. The 4-Hi and 4-Lo will work when I first start the car up, but never the A-4WD (like it's not even there). After driving awhile, the "Service 4-WD" light comes on and cannot shift into or out of any of these modes at all. So even if I've cleared the C0327 code, it will then come back up at this point. If I shut the car off awhile, system resets and can go thru the above again. Also getting a Loss of Class-II Communication with ATC (code U1026) and No State of Health from Module (U1000) codes.
Started a new thread because all other info on this subject does no seem to apply to my situation of course (encoder motor works, proper wheel(s) spin, fuses are all good, proper actuator motors are making their noises, TCCM and Switch have been replaced already, etc.). This is a new problem within the last week as I've used the 4WD several times already this season and I thought I had it licked because there was a broken wire near where the encoder motor plugs in to the wiring harness (4-WD would not engage at all and only got buzzing at the encoder motor, though selector switch said I was in A-4WD no matter where the knob was, but I was only in 2-Hi in actuality) that I fixed by bypassing the plug and just tying the wires together (orange wire I believe) and the system worked completely as designed for 2 days.
Question is:
1.) Can I just run a new ground from the plug at the encoder motor (bypassing the plug, but will be spliced in to the encoder motor wiring of course)?
2.) If so, and assuming it's the solid black wire coming out of the encoder motor, where do I ground it too (chassis, direct to battery, etc.) to see if that will work?
3.) If not either of the above, what do I test with my multimeter to tell me which wire or wires are bad from the encoder motor as my scantool will give me P and C codes, but won't get more specific than that for diagnosis?
4.) Should I just replace the whole wiring harness if even possible and not ridiculously complicated?
5.) Am I way off on all this and I need to do something else?
Sorry for all the questions at once, but I can't seem to find anything on the internet that pertains to my exact problem and I figure one of you guys will know what's wrong if explained to you properly. Feel free to ask follow-up questions, but that about sums it up for now.
skobie
Last edited:
