Four Wheel Anti-Lock Brake System (4WABS)

A2 DETERMINE IF THE CAUSE OF THE PROBLEM IS IN THE ELECTRONIC HYDRAULIC CONTROL UNIT (EHCU) OR THE WIRING

- Key "OFF."

- Connect the EEC IV 60-Pin Breakout Box.

- Remove fuse 21 (15A).

- Key "ON."

NOTE:
- Start wiggling the circuit at the endpoints or splices and work towards the middle.

- Measure the voltage between the breakout box pin 1 and chassis ground while wiggling the circuit.

Is the voltage greater than 0 volts at any time

> Yes
Repair circuit 603 (DG). A4

> No
If the fuse is open, check for a short to ground in circuit 603 (DG) or the indicator. A3