ABS And OBD Systems - Revised

MODEL
700-900

GROUP
59

NUMBER
904

MARKET
US and Canada

DATE
May 1993

TITLE
ABS BRAKING SYSTEM AND ON-BOARD DIAGNOSTIC (OBD) SYSTEM

700/900 1992-->

REFERENCE: TP 31085/1 (ENGLISH); 05/89; ABS BRAKE SYSTEM WIRING DIAGRAM
TP 32208/1 (ENGLISH); 12/92; WIRING DIAGRAMS 940 1993
TP 32200/1 (ENGLISH); 11/92; WIRING DIAGRAMS 960 1993

ABS braking system and on-board diagnostic (OBD) system







Replaced ABS control module, with an integral OBD function, p/n 9130197-8, was introduced into production from the illustrated chassis numbers.

From production month 4/93 the control module has a new p/n, 9128853-0. This control module is a replacement part and replaces older control modules on models from 1989 on.

The new control module OBD function is connected to position 3, diagnostic unit A in the engine compartment. When the control module discovers a fault, the ABS indicator lamp lights at the same time as it stores a DTC. During fault tracing/diagnosis the DTC can be read with the VST or by using the LED on the diagnostic unit by activating test function 1. See DTC table.

DTC TABLE




The DTCs in the table are listed numerically

When fault tracing, also see wiring diagram.

OBD ON OLDER MODELS

The new control module can be used to fault trace ABS on vehicles from 1992 up to the chassis numbers given at the beginning of this bulletin, to read off DTCs via the diagnostic unit.

Replace the existing control module with a new control module with an OBD function. Drive the car. Speed must exceed 4 mph (6 km/h). Faults will be posted by the control module which stores DTCs. These can then be read off via the diagnostic unit and test function 1. See DTC table above.

On M/Y '89-'91 fault tracing and diagnosis cannot be carried out using the new control module, as there is no diagnostic lead to the diagnostic unit.

Change location of sensor lead, M/Y '93 (Jan. - March) 940 with Rex/Regina ignition and fuel system

On cars with the Rex/Regina ignition/fuel system and an ABS control module, p/n 9130197-8, with OBD system, interference can occur in the sensor lead to the left front wheel. Interference can cause symptoms such as pulsing in the brake pedal when the car is stationary and the engine RPM is above idle. Normal braking function is not affected. If symptoms occur, modify sensor lead as per figure (see new position of sensor lead).




The routing of the sensor lead was changed from the hole in the wheel housing to the connector in the engine compartment. The lead was moved forward and pulled down towards the wheel housing plate. (See illustration). This measure was introduced into production from chassis number:

944 - 125305
945 - 075946




With the introduction of control module, p/n 9128853 in April '93, the risk of interference was eliminated. The sensor lead is now routed (in production) to the left front wheel as before, see illustration.

If fault symptoms occur:

Check that the sensor lead is routed in accordance with figure below.

New position of sensor lead

When re-routing the lead, ensure that the sensor lead is pulled towards the wheel housing plate. Secure the lead with wiring ties (p/n 945611-2) and flange screws M8x12 (p/n 947107-9) in the holes that already exist in the wheel housing. Put the rear cable grip over the connector.




WARRANTY STATEMENT: Claims may be submitted under the New Car Limited Warranty when a manufacturing defect is present using claim type: 01.