DORMAN 600-903 Transfer Case Motor Instruction Manual
- June 1, 2024
- DORMAN
Table of Contents
600-903
DIAGNOSTIC TROUBLE CODES: TRANSFER CASE MOTOR
600-903 Transfer Case Motor
ATTENTION: Refer to the appropriate shop manual for your vehicle to
obtain specific service procedures for this part. If you do not have a service
manual or lack the skill to install this part, it is recommended that you seek
the services of a qualified technician. Pay special attention to all cautions
and warnings included in the shop manual. Read and follow all instructions
carefully.
200802 Trailblazer/Envoy, 200803 Isuzu Ascender
DTC-C0306: Motor A or B Circuit Failure
Description: Diagnostic Trouble Code C0306 is set once the Transfer Case Control Module detects an open, short-to-ground, or low voltage in the Motor Control A or B circuit, or an open or short-to-ground fault inside of the transfer case motor.
How to access the diagnostic trouble code (DTC):
Once there has been a DTC set, the vehicle will either set a “service soon”
light, or the lights on the 4×4 switch will flash and/or stay lit. To access
the DTCs, you will need to hook up a vehicle diagnostic scanner utilizing the
service port under the driver side portion of the dash.
When to clear a DTC:
The diagnostic trouble code (DTC) should only be erased once the positive
voltage concern has been corrected.
How to clear a DTC:
- The Transfer Case Control Module (TCCM) will clear the DTC once the initial problem has been fixed.
- A hard DTC will clear once the vehicle has run through one hundred (100) start cycles and detects no faults.
- To clear the DTC manually, you will need a vehicle diagnostic scanner (Scan tool). Once the DTC has been erased, go back into the vehicle system and verify that the DTC has been erased and that the system is performing properly.
DTC-C0321: Motor A or B Circuit Failure
Description:
DTC-C0321 will be set when the Transfer Case Control Module (TCCM) finds a
fault in an open lock solenoid, open motor lock control, or an open motor
feed. This will cause the 4WD to be disabled and will turn on the Service 4WD
trouble light.
What causes DTC-C0321:
- The transfer case motor lock feature detects the improper voltage.
- The Transfer Case Control Module (TCCM) detects no voltage going to the Transfer
Case Motor (TCM) lock feature.
How to access the diagnostic trouble code (DTC):
Once there has been a DTC set, the vehicle will either set a “Service 4WD”
light, or the lights on the 4×4 switch will flash and/or stay lit. To access
the DTCs, you will need to hook up a vehicle diagnostic scanner utilizing the
service port under the driver side portion of the dash.
When to clear a DTC:
The diagnostic trouble code (DTC) should only be erased once the voltage
concern has been corrected.
How to clear a DTC:
- The Transfer Case Control Module (TCCM) will clear the DTC once the initial problem has been fixed.
- A hard DTC will clear once the vehicle has run through one hundred (100) start cycles and detects no faults.
- To clear the DTC manually, you will need a vehicle diagnostic scanner (Scan tool). Once the DTC has been erased, go back into the vehicle system and verify that the DTC has been erased and that the system is performing properly.
DTC-C0327: Motor A or B Circuit Failure
Description:
DTC-C0327 will be set when the Transfer Case Control Module (TCCM) finds an
electrical fault in the Transfer Case Encoder Circuit.
What causes DTC-C0327:
DTC-C0327 will set when the Transfer Case Control Module detects a variation
in the specified voltage for the Transfer Case Encoder circuit. Another
possible cause for DTC-C0327 could be a mechanical concern within the Transfer
Case Shift assembly. The Transfer Case encoder detects the position of the
shift shaft assembly on the Transfer Case. Over time, the shift shaft assembly
could develop lateral or vertical movement and cause the Transfer Case Encoder
to detect a false reading and set a trouble code.
How to access the diagnostic trouble code (DTC):
Once there has been a DTC set, the vehicle will either set a Service 4WD light
or the lights on the 4×4 switch will flash and/or stay lit. To access the
DTCs, you will need to hook up a vehicle diagnostic scanner utilizing the
service port under the driver side portion of the dash.
When to clear a DTC:
The diagnostic trouble code (DTC) should only be erased once the voltage
concern has been corrected, or the mechanical problem has been addressed.
How to clear a DTC:
- The Transfer Case Control Module (TCCM) will clear the DTC once the initial problem has been fixed.
- A hard DTC will clear once the vehicle has run through one hundred (100) start cycles and detects no faults.
- To clear the DTC manually, you will need a vehicle diagnostic scanner (Scan tool). Once the DTC has been erased, go back into the vehicle system and verify that the DTC has been erased and that the system is performing properly.
DTC-C0374: General 4WD Failure
Description:
DTC-C0374 will be set when the Transfer Case Control Module (TCCM) detects
rear wheel slippage. Once the TCCM attempts to apply torque to the front
wheels and cannot, DTC-C0374 will be set. When DTC-C0374 is activated, you
will not be able to use your AUTO 4WD. The SERVICE 4WD light will remain on
until you re-start your vehicle.
What causes DTC-C0374:
DTC-C0374 will set when the Transfer Case Control Module detects a variation
in the front drive shaft and rear drive shaft speed sensor, and is not able to
engage the front dierential after ten (10) unsuccessful attempts.
How to access the diagnostic trouble code (DTC):
Once there has been a DTC set, the vehicle will either set a Service 4WD
light, or the lights on the 4×4 switch will flash and/or stay lit. To access
the DTCs, you will need to hook up a vehicle diagnostic scanner utilizing the
service port under the driver side portion of the dash.
When to clear a DTC:
The diagnostic trouble code (DTC) should only be erased once the voltage
concern has been corrected, or the mechanical problem has been addressed.
How to clear a DTC:
- The Transfer Case Control Module (TCCM) will clear the DTC once the initial problem has been fixed.
- A hard DTC will clear once the vehicle has run through one hundred (100) start cycles and detects no faults.
- To clear the DTC manually, you will need a vehicle diagnostic scanner (Scan tool). Once the DTC has been erased, go back into the vehicle system and verify that the DTC has been erased and that the system is performing properly.
Disclaimer: Even though every attempt is made to ensure this information is complete and accurate, it is impossible to account for all possible circumstances or situations. Please consult with a qualified auto technician before attempting to perform any work you are not qualified to do. Automobiles can be hazardous to work on; be sure to take all necessary safety precautions. Failure to do so may result in property damage or personal injury. Certain motor vehicle standards and performance requirements may apply to your motor vehicle (such as Federal Motor Vehicle Safety Standards by the National Highway Traffic Safety Administration). Be sure that your work is performed in accordance with such standards and that you do not disable any motor vehicle safety feature.
©2012 Dorman Products, Inc.
No reproductions in whole or in part without prior written approval.