Hydraulic Modulator/Pump Relay Ground Circuit Test

Turn ignition off. Reconnect pressure switch connector. Depress brake pedal 20 times. Using an ohmmeter, check for continuity between ECU connector terminals No. 1 and 14. If continuity exists, go to next test. If continuity does not exist, check for continuity between pressure switch terminals No. 1 (Brown wire) and 4 (Red/Yellow or White wire). See Figure and Figure thru Figure . If continuity does not exist, replace pressure switch, and retest. If continuity exists, check wiring between ECU terminal No. 14 and pressure switch terminal No. 4. Repair wiring, and retest.