Taillight Control Relay Circuit

Turn ignition off. Disconnect ECU connectors. Using voltmeter connected to ground, backprobe ECU connector T8 terminal No. 23. 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 found to be defective, replace ECU and retest system.