Electrical - Battery Discharged
Date: March 11, 2009Order No.: T-B-54.21/198f
Supersedes: T-B-54.21/198e dated Jan. 6, 2009
Group: 54
Revision History
SUBJECT:
Model 164.122/172/177/186/822/871/886
Model 251.122/156/165
Model Year 2008
Battery Discharging - Increased Rest Current in the Rear SAM / CAN Bus Awake Mode Software in Steering Column Module (SCM)
If you receive customer reports in the above model vehicles that the battery has completely discharged, this may be due to the following.
Note:
Before performing repairs as described below in Remedy 1 or 2, determine (by using Star Diagnosis) whether flashing was performed or if the upgraded part has already been installed. The battery discharge may be caused by any installed electronic device or accessory or could be inadvertently caused by customers action.
Cause 1 (Vehicles equipped with Automatic Rear End Door (SA code 890) or Keyless-Go (SA code 889):
Rest current being too high (>150mA but less then 3Amps) resulting from the rear SAM staying awake due to incorrect rest current logic. This situation may occur if the tailgate button on the key is pressed to open while vehicle is locked. Once the tailgate is closed again, the rear SAM remains awake before the tailgate lock switch and the spare wheel carrier switch close. If the spare wheel carrier is not installed (SA code 849), the SAM remains awake and drains the battery. The CAN bus however, is not awake in this case.
Note:
Remedy 1: As of November 21, 2008, Remedy 1 of this DTB must not be performed on the subject vehicles as it is covered by Service Campaign T-SC-2008110009. Combining Remedy 1 of this DTB with the referenced Campaign will result in a charge back.
Cause 2:
Battery discharges due to software issue in the Steering Column Module which causes the CAN bus to remain in awake mode (rest current >3Amps).
Remedy 2:
Replace the Steering Column Module (SCM) as per WIS document AR46.10-P-0300GZ (164) or AR46.10-P-0300RT (251).
As of end June 2008 production, Models 164 (VIN A441045) and 251 (VIN A089020) vehicles are fitted with an updated Steering Column Module.
Cause 3 (Vehicles equipped with Automatic Rear End Door (SA code 890) or Keyless-Go (SA code 889):
Battery discharges due to tailgate striker not adjusted properly. This may prevent the rear-end door control module (REDC) from recognizing when the latch is in the first detent position.
Remedy 3: Adjust the striker as below:
In the Y-direction: The liftgate lock must run into the center of the striker. If the gap dimensions are not in specification, correct at the hinge.
In the X-direction: The liftgate should be as flush as possible with the edges of the fender. Move the striker as far forward in the direction of travel without compromising the appearance of the liftgate flushness.
Note:
A slight recessed rear-end door increases the preload of the seal and improves the functional reliability of the power closing system.
Note:
The gap dimensions for the tailgate can be found in WIS documents AR72.20-P-3510GZ and AR72.20-P-3510RT.
After all modifications have been completed, perform a function test to verify that the liftgate closing assist system is operating correctly on a consistent basis. The liftgate must be pulled closed (to the main detent) by the power closing mechanism without fail.
Note:
To better understand the tailgate adjustment procedure, please reference the mobile training coach for a video that illustrates this process in detail. The video can be found at http://www.mbusadigitalmedia.com/MTC/pages/allmtc.aspx via group 72 in the drop down menu.
Parts Information
Note:
The following allowable labor operations should be used when submitting a warranty claim for this repair. This information has been generated on March 11, 2009. Please refer to Netstar --> Star TekInfo --> Star Time for the most current labor time allowance.
In Case of Warranty, use the table.