Power & Ground Circuits
- Ensure ignition is off. Disconnect connectors from ECU. Remove locks so ECU connector can be easily backprobed. See Fig 1. Reconnect ECU connectors.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- Turn ignition on. Using a DVOM, measure voltage between ECU terminals B1 and E1. See Figure. Measure voltage between terminals B and E1. Battery voltage should be present.
- If battery voltage is not present, ensure wire harness is not open or shorted. If wire harness is okay, replace ECU.