Unable To Complete A transfer Case Module Relearn Procedure DTCs C0387Or C0569 - keywords calibrate MIL TCCM
| Subject: | Unable to Complete a Transfer Case Module Relearn Procedure DTC's C0387 or C0569 |
| Models: | 2008 Chevrolet Avalanche Suburban, Tahoe |
| 2007-2008 Chevrolet Silverado |
| 2007-2008 GMC Sierra |
| 2008 GMC Yukon, Yukon Denali, Yukon XL |
| Equipped with Transfer Case RPO NQF or NQH |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
Some dealer technicians may comment about difficulties encountered in an attempt to complete a transfer case module relearn procedure. DTC's C0387 or C0569 may be set.
Recommendation/Instructions:
Insufficient electrical system voltage during relearn procedure. As the system completes the relearn system voltage is critical. A voltage of 10.5 or higher is required to successfully complete the procedure without setting DTC's.
There are two methods for completing a TCCM relearn. The first method involves using a scan tool. The technician simply selects the 'Motor Learn Procedure' and follows the directions. The second method involves using the transfer case control switch. With the ignition switch in the accessory position cycle the transfer case control switch from 2HI to the Neutral detent. Hold for 30 seconds. In order for the procedure to work properly you must start out in the 2HI mode. Reference SI document 1865237.
During the procedure the transfer case completes an end rail shift to find it's true position. On an NQH transfer case the module is looking at readings from the Rotational Position Sensor and Incremental Sensor. As the end rail shift is completed an audible noise from the motor should occur indicating a successful learn procedure. If the battery voltage is at 10.5 volts or below the sensor readings will be compromised and the following DTC's will set.
C0387 - Unable to Complete Shift - Circuit/Component Protection Time-out
C0569 - System Configuration Error - Calibration Data Not Learned
Technicians may use the Midtronics 165-PSC charger, or a 12-volt jumper pack to maintain battery charge during programming (reference June 2006 Techlink article).
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.
