2001 Jimmy SLS
2Hi, 4Hi, 4Lo, Auto (so 4 buttons)
so I think this is the 233??

service 4wd light is on and now the buttons lights have died.

I have the following Codes

CO387 unable to complete shift
CO327 Encoder Circuit
B2725 active Transfer case Module switch fault


The CO387 makes me wonder if it is the transfer case. If the transfer case can't be shifted then it would trigger the other codes or does this all point to the motor?

Most of the articles on the site I have read were unsuccessful in fixing this problem. Who has encountered this and solved it themselves? How did you insure your transfer case was in Neutral. Was there any issues in installing the motor? I can buy the Doorman shift motor here in Ontario new for 252.00.

 

if the Encoder (shift) motor was bad the button lights would still work. The wiring needs checked. Make sure the TCCM is getting power and has a good ground.

 

Check the TCCM

 

My mechanic buddy just left the TCM is good and we have power, He said the drive shaft felt bad and I pulled it off, it is definitely bad the seal was busted and I could see the Small round bearings inside. Pulled of the motor as well. Lights were back on again on the dash before we ripped it apart. Could a bad shaft cause those codes as well. Going to try and get a used shaft tomorrow seen one for 75.00 supposedly on 60,000 km (35,000 miles). Will also pick up another motor just in case.

 

the only things that can throw the code for the 4x4 system is the shift motor, TCCM, wiring, or vacuum actuator. Your shift motor may be bad, they are known to fail. No, the condition of the drive shaft wont throw a 4x4 code. Once again, a shift motor alone wont cause the 4x4 lights not to work. What would happen is when you press a button it would flash for a while then go back to what is was at.

 

I have a faulty motor right now and it will go in to 2 HI or 4 LO and it will NOT go in to 4 HI or Auto 4WD. The faulty motor can only shift to either extreme but not the modes in between. Ill pm you a really good thread you should look over.

 

Thanks guy's. Last year I replaced the cable the actuator was fine I also replaced the vac hoses as they crumbled from age. The drive shaft I should have known better and checked it last year. So I purchased a new coder motor 250.00 Canadian taxes in from Doorman. The drive shaft still looking for a used probably 120.00.

A mechanic buddy of mine tested the TCCM and the voltage going to the motor he thinks it is the motor. I was just thinking that the code CO387 Unable to shift could also indicate a bad transfer case and if it can't shift it would throw that code triggering the others. I guess after this I should have a good feel for the 4x4 system.

Well hope I can get this done before the long weekend, have to find the drive shaft.

 

Thought I would update this thread. So I purchased a new shift motor and had drive shaft rebuilt. Rebuilt shaft 395.00 Canadian, shift motor new 250.00 Canadian.

Just replaced the parts today and seems to be working.