Suspension - Height Randomly Changes
Date: October 29, 2008Order No.: P-B-32.50/35c
Supersedes: P-B-32.50/35b dated Feb. 22, 2008
Group:32
Revision History
SUBJECT: Model 215.373/374/375/376/378/379
Model 220.067/083/170/173/174/175/176/178/179/183/184, Equipped with Code 487 (Active Body Control)
Model 230.471/472/474/475/476/477/479, Up to VIN F118817
Random Vehicle Level
If you receive customer reports in the above model vehicles of the vehicle's suspension level randomly lowering while driving and/or rapid sporadic level changes shortly after stopping the vehicle, replace the body acceleration sensors (reference WIS document GF32.31-P-4100A), with a manufacturing date greater than 02 W 01 (Year 2002, week 01) (Figure 1).
NOTE:
Do not replace any other ABC suspension components.
In both of the above scenarios, vehicle level changes typically occur intermittently and predominately after driving for extended periods. The vehicle's level adjusts without obvious cause, and usually quickly moves upwards or downwards, and then rapidly corrects back to the specified level.
Random level movements (while driving) only occur when the ABC suspension system is in Active mode (i.e. when the vehicle is in motion). Thus, the above mentioned level movements cannot occur when the ABC system is in Passive mode (i.e. vehicle stopped). Since the ABC system does not switch to Passive mode until a few seconds after the transmission gear selector is positioned into Park or a significant braking torque is applied for several seconds, sporadic level conditions may exist shortly after stopping the vehicle. Random level conditions may also exist shortly after stopping the vehicle if the vehicle is stationary but an insufficient amount of braking torque is applied, thus causing the system not to switch to Passive mode.
NOTE:
The random level control is the result of tolerance contact issues on the printed circuit board of the body acceleration sensors [B24/3-front left, B24/4-front right, B24/5-rear left (Model 230), B24/6-rear right (Model 220/215)], in combination with the sensors heating up after an extended period of driving. The contact issue can result in a higher internal resistance on the printed circuit board causing the sensor to output an incorrect signal, thus initiating an ABC adjustment.
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 February 22, 2008. Please refer to Netstar -> Star TekInfo -> Star Time for the most current labor time allowance.
In Case of Warranty
Operation: Accel. Sensor - Frt. left for Act. Body Control (ABC), replace (32-7530)
Accel. Sensor - Frt. right for Act. Body Control (ABC), replace (32-7531)
Accel. Sensor - Rear right for Act. Body Control (ABC), replace (32-7533)
Accel. Sensor - Rear left for Act. Body Control (ABC), replace (32-0000)