Customer complains about anti-theft alarm system triggering without obvious cause when the vehicle is...

Bulletin number

LI80.50-P-077350

Component

Electrical system

Summary

Complaint Customer complains about anti-theft alarm system triggering without obvious cause when the vehicle is parked and/or when entering the vehicle. All MFA2 and 167 derivates with code 882 may be affected. Cause This is caused by a sporadic loss of communication to the anti-theft alarm system [N26/6]. In many instances there are one or more FCs U110D87, U001988, U016787 stored in the control units anti-theft alarm system [N26/6] and/or signal acquisition and actuation module [N10] / [N10/6]. The alarm system memory may contain several alarm sources. Remedy Please process all following points in succession: 1. Initial problem - Power supply of the overhead control panel [N70] - Ground points of the overhead control panel [N70] • Model series 118, 177, 247: W78 • Model series 167: W15/2 • Model series 243: W78/2 - LIN lines between overhead control panel [N70] and alarm siren [H3/1] - CAN lines between overhead control panel [N70] and signal acquisition and actuation module [N10] or [N10/6] - Delete fault memory and recheck vehicle Note - If wiring fault is found in newer vehicle, please send in a IFQ (Initial Field Quality) TIPS Case. 2. Subsequent problem after repair In this case, the workshop must perform the following operation steps: - Replace overhead control panel [N70] (anti-theft alarm system [N26/6] is integrated) - Clean electrical connectors of overhead control panel with commercially available contact cleaner and clean, purified compressed air. - Delete fault memory and recheck vehicle Note - If no remedy is found, please open a TIPS case and send to the Body/Chassis/Entertainment inbox.

Owners of these vehicles have filed 256 complaints in the electrical category.