Diagnostic Procedures Overview

WARNING: BRAKE FLUID CONTAINS POLYGLYCOL ETHERS AND POLYGLYCOLS. AVOID CONTACT WITH EYES. WASH HANDS THOROUGHLY AFTER HANDLING. IF BRAKE FLUID CONTACTS EYES, FLUSH EYES WITH RUNNING WATER FOR IS MINUTES. GET MEDICAL ATTENTION IF IRRITATION PERSISTS. IF TAKEN INTERNALLY, DRINK WATER AND INDUCE VOMITING. GET MEDICAL ATTENTION IMMEDIATELY.

CAUTION: Do not spill brake fluid onto painted surfaces. If spilled, wipe it up immediately.

Anti-Lock Brake Control Module Ground:

NOTE:
- The control module ground must be verified before any measurement involving those pins can be made.
- EEC-IV 60-Pin Breakout Box pin numbers may not match anti-lock brake control module pin numbers.

Throughout the pinpoint tests, many of the values given depend on the presence of a good ground available at pins 18, 19, 21, and 60. Once the EEC-IV 60-Pin Breakout Box and 40/60-Pin ABS Adapter Cable are installed, check for continuity between pins 18, 19, 21, and 60 and ground.

CAUTION: The two circuits between the anti-lock brake control module and each brake anti-lock sensor are twisted together at intervals of approximately one turn per 25.4 mm (1 inch). When circuits are repaired, be sure to restore the turns to ensure proper shielding.

NOTE: Do not proceed to any pinpoint test unless directed to do so.

These tests are specific for each DTC. However, jumping to a pinpoint test as the first step can be misleading. The tests have been written under the assumption that the System Pre-Check has been performed and passed.

At times, running completely through the pinpoint test will not lead to concern resolution. Often, the concern is due to an intermittent connection, termination, or circuit concern. When situations like this arise go to the Intermittent Failures Test.

NOTE:
- Always check the fluid level in the brake master cylinder before performing the test procedures. If the fluid level is not at the MAX line, add High Performance DOT 3 Motor Vehicle Brake Fluid C6AZ-19542-AB or DOT 3 equivalent meeting Ford specification ESA-M6C25-A, DOT 3.
- The only part of the HCU assembly that is replaceable is the coil assembly. The rest of the HCU assembly is not repairable nor can it be pressure checked. If any part other than the coil assembly fails, the HCU assembly must be replaced as a complete unit.
- Radio Frequency Interference (RFI) can cause false Diagnostic Trouble Codes (DTCs) to be generated if aftermarket electrical work has been done.

NOTE: Problems in other areas may affect the operation of the ABS system. Those areas include:
- Steering and suspension.
- Tire integrity and air pressure.
- Wheel bearings.
- Brake components that are common to all brake systems.