Drivetrain - 'Service 4WD' Light ON/DTC C1078 Stored
NUMBER: 21-009-11GROUP: Transmission and Transfer Case
DATE: July 13, 2011
THIS SERVICE BULLETIN IS ALSO BEING RELEASED AS RAPID RESPONSE TRANSMITTAL (RRT) 11-073. ALL APPLICABLE SOLD AND UN-SOLD RRT VIN's HAVE BEEN LOADED. TO VERIFY THAT THIS RRT SERVICE ACTION IS APPLICABLE TO THE VEHICLE, USE VIP OR PERFORM A VIN SEARCH IN TECHCONNECT. ALL REPAIRS ARE REIMBURSABLE WITHIN THE PROVISIONS OF WARRANTY.
HELP USING THE wiTECH DIAGNOSTIC APPLICATION FOR FLASHING AN ECU IS AVAILABLE BY SELECTING "HELP" THEN "HELP CONTENTS" AT THE TOP OF THE wiTECH DIAGNOSTIC APPLICATION WINDOW.
THE wiTECH SOFTWARE LEVEL MUST BE AT RELEASE 12.01 OR HIGHER TO PERFORM THIS PROCEDURE.
SUBJECT:
Flash: Service 4WD Light Illuminated With C1078 Stored
OVERVIEW:
This bulletin involves flash reprogramming the Drive Train Control Module (DTCM) with new software.
MODELS:
2011 (DS) RAM 1500 Pickup
2011 (DX) RAM Truck (Mexico)
NOTE:
This Service Bulletin applies to vehicles equipped with electronic shift on demand transfer case (sales code DH8) built before May 13, 2011 (MDH 0513XX).
SYMPTOM/CONDITION:
Some customers may get a "Service 4WD" light in the Cabin Compartment Node (CCN).
Upon further investigation the Technician may find that C1078 - Tire Revolutions Range Performance diagnostic trouble code (DTC) is set in the DTCM.
This condition may occur when driving on a slippery road and the system is monitoring for slipping wheels. Under these conditions the system may incorrectly determining that one wheel is spinning too much. When the system detects this, it shuts down the 4WD capability for the remainder of the drive cycle. The system is overly sensitive to wheel slip
and may set this DIG when no issue is present.
The system was re-calibrated to allow more wheel slip before setting this DIG. This condition is not monitored when operating in 2WD mode. Updating the DTCM software will correct the conditions above.
DIAGNOSIS:
Using a Scan Tool (wiTECH(TM)) with the appropriate Diagnostic Procedures available in TechCONNECT, verify no DTC's are set. If DTC's are present other then the one listed above record them on the repair order and repair as necessary before proceeding further with this bulletin.
If a customer's VIN is listed in VIP or your RRT VIN list, perform the repair. For all other customers that describe the symptom/condition or if the technician finds the DTC, perform the Repair Procedure.
PARTS REQUIRED:
REPAIR PROCEDURE:
NOTE:
Install a battery charger to ensure battery voltage does not drop below 13.2 volts. Do not allow the charging voltage to climb above 13.5 volts during the flash process.
NOTE:
If this flash process is interrupted/aborted, the flash should be restarted.
1. Reprogram the DTCM with the latest software. Help using the wiTECH diagnostic application for flashing an ECU is available by selecting "help" then "help contents" at the top of the wiTECH diagnostic application window. After DTCM reprogramming, the following must be performed:
a. Clear any DTC's that may have been set in other modules due to reprogramming. The wiTECH application will automatically present all DTCs after the flash and allow the tech to clear them.
2. Type the necessary information on the "Authorized Modification Label" and attach it near the VECI label.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
Failure Code:
Disclaimer:
This bulletin is supplied as technical information only and is not an authorization for repair.