Hello and welcome to Just answer.com, Super mechanic here. About your vehicle.
It sounds like it may be the shift motor, (encoder motor) in the transfer case, but you will want to see what trouble code(s) may be stored in it.
The diagnostic trouble codes are displayed on the three transfer case shift select buttons. The Shift select buttons are located on the instrument panel. When connector pin 13 on the data link cable is grounded, and the ignition switch has been off for at least five seconds prior to positioning the ignition switch to run, the shift select buttons will blink various times together to indicate diagnostic trouble codes from 1 to 4.
DIAGNOSTIC TROUBLE CODE (DTC) 1 When the ignition switch is positioned to "RUN", the TCCM test to determine if RAM Standby Power (maintained battery power) to the TCCM was lost since the ignition was last turned off. When power is interrupted on pin C6 of the TCCM, the TCCM stores a "loss of RAM Standby Power" DTC 1.DIAGNOSTIC TROUBLE CODE (DTC) 2 During electronic shifting, the TCCM checks the motor/encoder for normal operation. If the motor/encoder does not function correctly enough times, the TCCM stores a "motor/encoder failure" DTC 2.DIAGNOSTIC TROUBLE CODE (DTC) 3 The TCCM performs a test each time the electric-shift motor is turned on or off. If the motor is not functioning properly the TCCM stores a "motor circuit failure" DTC 3, and the shift select buttons blink to inform the driver of a problem.DIAGNOSTIC TROUBLE CODE (DTC) 4 Each time the ignition is turned on, the TCCM tests it's memory, program, and internal system to ensure that it is operating properly. If the TCCM detects a fault within itself, the TCCM stores a "RAM/ROM memory failure" (DTC) 4.
When performing the DTC code test above, I get no lights on the switches when pin 13 is grounded and when the switch is turned to run. What does that mean?
You would then want to start with the functional check. (may want to check the fuses first)
Symptom Diagnostic Tables - NV 243 (Electric Shift)
Table 2: Functional Test Failed
Let me know if you need more
Well I replaced both fuses and got a system ok or all three lights blinked once and the a pause of three seconds and then again. Following the tables, it points me to table 8, which I don't have? Any thoughts?
Let me give you the next few tables. It sounds like your making some progress with it. Then you can try the diagnostic again to see what codes may be there.
The code #1 may have been set by taking out the fuse. It looks like a code #3, which is the encoder motor, (most likely) let me see if there are any tests that can be done on it.
DIAGNOSTIC TROUBLE CODE (DTC) 1 When the ignition switch is positioned to "RUN", the TCCM test to determine if RAM Standby Power (maintained battery power) to the TCCM was lost since the ignition was last turned off. When power is interrupted on pin C6 of the TCCM, the TCCM stores a "loss of RAM Standby Power" DTC 1.
DIAGNOSTIC TROUBLE CODE (DTC) 3 The TCCM performs a test each time the electric-shift motor is turned on or off. If the motor is not functioning properly the TCCM stores a "motor circuit failure" DTC 3, and the shift select buttons blink to inform the driver of a problem.
Whenever the electric-shift motor is turned on or off, the motor and its electrical circuits are tested both in the de-energized and energized condition. If one or both voltage relays fail to detect the proper voltage after energizing or de-energizing, the shift is aborted by the Transfer Case Control Module (TCCM) and a DTC of 3 is stored to indicate a faulty TCCM motor circuit.If one or both relays fail to detect the proper voltage after de-energizing, both relays are turned on by the TCCM (even with the ignition switch positioned off) to prevent the motor from running. The TCCM then stores a DTC of 3 to indicate a faulty TCCM motor circuit. The all the status lamps blink three times, stop, and repeat the blinking continuously to alert the driver that the electronic shift system requires immediate repair. The battery will drain when this condition occurs, regardless of the ignition switch position.
I ran some more tests and have continued to be able to get it in and out of 4hi and 4lo, but by playing around with it. Ultimately, it gets to the point where it will only switch from 2Hi to 4Lo and in drive it won't even activate from 2HI to 4HI. After that state I pull the codes and get all three lights one time + 3 secs + all three lights twice + three secs and repeat I did a clear before each test, 45 seconds with #2 fuse out and then 5 times cycling the ign switch to run. I'm thinking that there is something wrong with the TCCM and also possibly the motor/encoder. I checked all the wires to the motor, looks good.
Anyway, your thoughts and I would also like to give you a tip for your help....
Thanks but we are not allowed to have any communication outside of the posts.
It does sound like the encoder/motor is bad. I would go with that before condenming the TCCM first thing. Here is the only thing that the data base has for the testing of it.
While the transfer case is shifting, the encoder within the electric-shift motor is monitored for the proper operating sequence. If during a shift, the encoder changes to a incorrect position, an error counter in the TCCM starts to count the number of times the encoder fails. If the encoder fails eight times, the Transfer Case Control Module (TCCM) produces a DTC of 2 indicating a (Encoder Fault). When this happens, the TCCM outputs a signal to default the rail shift pattern in the encoder to allow for only shifts into 2Hl and 4LO.To protect against transient, random encoder faults caused by vibration, contamination, electrical noise, etc., the error counter reduces its count by one each time a good encoder value is detected. The encoder must fail 25 percent of the time for TCCM to store a DTC of 2 and indicate a damaged encoder.
Well, I just replaced the motor/encoder and still have the problem, except that when I put the car into nuetral, I can get into and out of 4lo to 2hi consistantly. After fooling with it for a while, the TCCM throws a code and then I can't get the dash switch to even activate from 2hi to 4hi in gear. It still will go to 4lo in neutral. Code pattern is all three lights flash twice and then repeat. Think it is the TCCM?
Well I made progress, at least I can depend on it getting me in and out of 4LO for those times when I need it. 4HI is a luxury for now. Don't think it is the TCCM. I'm still not sure how to read the codes. I get all three lights blinking twice and then repeat. Why does that mean 3? How would 4 be shown?
That should be code 2..code 4 would blink 4 times. Normally, a code 2 will set ater the TCCM sees that there is a problem with going into and out of 2wd and 4wd modes.
You might want to try clearing the code(s) if you haven't already. Then see how it does.
If I clear the codes, it allows me to press the 4HI in gear and flashes and then a clunking sound and then it flips back to 2HI. Sometimes it will work if I am moving, but after a few failed times and once code 2 is set, it stops allowing me to try switching to 4HI in gear. 4LO always works now in neutral from 2HI and back. I guess there may be a mechanical problem in the transfer case.