Taillight Control Relay Circuit

Turn ignition off. Disconnect ECU connectors. Using voltmeter connected to ground, backprobe ECU 12-pin connector T3 terminal No. 11 (Green/Red wire). See Figure. If voltage reading is not 10-14 volts, repair wiring between ECU and taillight control relay. If voltage reading is 10-14 volts, check ECU. See PIN VOLTAGE TESTS . If pin voltages are not within specification, replace ECU and retest system operation.