Important information on repairs - RA42001240702X(42-0702)

WARNING: This page does not describe the selected car, but rather 42 other vehicles, including the 1999 Mercedes-Benz S600, 1999 Mercedes-Benz S500, 1999 Mercedes-Benz S420, 1999 Mercedes-Benz S320, and 1999 Mercedes-Benz CL600. However, it is still accessible from the selected car via links, so may be relevant.

Always observe the following when servicing ABS-equipped vehicles:

Welding

Before using an electric welder, always remove the plug from the ABS control unit and remove the ground cable from the battery.

Painting

In the drying booth the ABS control unit should not be exposed to temperatures of more than 95°C for brief periods, or more than 85°C for longer periods (approx. 2 hours).

Battery installation

If the battery has been removed, ensure that both cables are tight on their respective terminals during reinstallation.

Rear axle center section

When replacing or servicing the rear axle center section, ensure that the drive gear for the wheelspeed sensor is the correct unit for the final drive ratio.

Testing operation

After any work in which components of the ABS have not been directly affected, the ABS malfunction indicator lamp in the instrument cluster will provide an adequate check. After the engine starts, the malfunction indicator lamp should go out if the ABS unit is in order.

Operations in which the no ABS components are directly affected include:

Exchange or replacement of brake calipers, brake pads, brake hoses, brake disks, brake booster, tandem master cylinder, brake cables and components of the parking brake as well as the brake lines to the rear axle.

After work on the hydraulic unit, on the ABS control unit, on the wiring harness and on the wheel-speed sensors, and after replacement of component assemblies (for example, in the course of accident repairs), the entire ABS must be tested with the available ABS test adapter and a multimeter.

The Bosch ABS tester ETT 016.00 is no longer suitable for performing the entire range of test procedures; thus test adapter 126 589 01 21 00 should always be used.

When testing Models 124.034, 129.058/063, 140, 202 use a pulse counter and/or hand-held tester, multimeter and terminal box in accordance with the instructions in the Chassis Diagnosis Manual, Volume 2.

Handling of ABS parts on vehicles involved in accidents

If it is apparent from the extent of damage to the vehicle or to the position and external appearance of the hydraulic unit after an accident, that the hydraulic unit has received a severe blow, it is to be replaced.

Symptoms of this are, for example:

Hydraulic lines kinked
Connections on hydraulic unit leaking
Electric cables or plug connectors damaged
The metal block of the hydraulic unit shows signs of damaged
The hydraulic unit has sprung out of its mounting and cannot be put back easily

Should this not be the case, the system must nevertheless be subject to a thorough function check and the test steps carried out for the solenoid valves and pump.