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 No. 4 (Red/Yellow or White wire). See WIRING DIAGRAMS. 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.