Technical information

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Technician Guidelines for Antilock Braking Systems

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III. ABS TROUBLESHOOTING, MAINTENANCE &

INSPECTION

Although an ABS generally requires no routine

maintenance, it should be checked periodically like other

components of the air brake system.

In this section, we review various aspects of ABS

troubleshooting, maintenance and inspection. When you

complete this section, you should understand:

• General ABS troubleshooting principles

• Special concerns about connector repairs

• ABS error detection methods

• Common ABS errors and causes

• General ABS component adjustment, installation and

removal procedures

A. ABS Troubleshooting

1. General Diagnostic Principles

This section describes general principles of electrical,

electronic, and air system diagnostics to provide technicians

with a plan of action for ABS troubleshooting. Chart 1 on page

15 illustrates these diagnostic principles in flow chart form. The

following sub-sections—based on The Maintenance Council’s

Recommended Practice TMC RP 1406, “Basic Electrical/

Electronic Diagnostic Procedures”—cover this process in detail.

Step 1: Verify the problem or driver concern.

Establish the connection between the symptom and the

underlying cause of the problem. Use the vehicle

manufacturer’s recommended information collection methods

for verification.

Step 2: Perform preliminary checks.

Operational, visual and audio checks are generally easy to

perform, do not require the use of special tools and may result

in a quick diagnosis. This is a critical step in the diagnostic

process.