System Introduction

NOTE: For model name/model number cross reference refer to Model Designation Table. Application and ID

ABS/ASR III

The acceleration slip control as known from model 129 (ASR II) has been revised and is now known as ASR III (3rd version).

The following is a description of modifications as compared to ASR II.

All modifications concerning the electronic accelerator system are described in "Computers and Controls".

ABS is standard equipment in all model 140 vehicles. ASR is standard equipment in models 140.051/057 and optional in all other model 140 vehicles.





The ABS and ABS/ASR control units (N30, N30/1) were revised and are now equipped with diagnostics. Recognized malfunctions are stored in the control unit and can be retrieved via the 38-pole test connection for diagnosis using an impulse counter, and subsequently checked with the socket box tester. For ABS/ASR tests, refer to Testing and Inspection. Testing and Inspection





Voltage is supplied by the base module (N1 6/1). The control units are located in the module box.

In models 140.04/05, the ABS or ABS/ASR control unit (N30 or N30/1) processes signals from the lateral acceleration sensor (B24/2) and controls the master brake cylinder switchover valve (Y61) accordingly.





Lateral acceleration sensor (B24/2)
The lateral acceleration sensor is located under the right rear seat and is a Hall-effect sensor, which transmits a lateral acceleration input to the ABS and/or ABS/ASR control unit. This allows a brake proportion change when driving in curves at high speed.

The lateral acceleration sensor is very sensitive to shock. When performing repairs near the lateral acceleration sensor involving heavy shocks, e.g., hammer blows, the lateral acceleration sensor must be removed and later reinstalled.


NOTE: As of MY 1993, the ABS/ASR control module (N30/1) is equipped with diagnostic capability and is installed in the module box (F23).

Voltage is supplied by the base module (N16/1). For diagnostic tests, see Testing and Inspection.