Inspection Procedure

WARNING: This page is about a different car, the 2004 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT HYBRID VEHICLE CONTROL ECU (ST2 VOLTAGE)

Disconnect the H14 HV control ECU connector.

Measure the voltage between the terminal of the HV control ECU connector and body ground with the power switch turned OFF.

VOLTAGE CHECK

Tester Connection	Specified Condition
ST2 (H14-5) - Body ground	Below 1 V

Reconnect the HV control ECU connector.

NG: Go to step 2

Fig 1: Disconnecting H14 HV Control ECU Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go To Next Step

CHECK FOR INTERMITTENT PROBLEMS (See CHECK FOR INTERMITTENT PROBLEMS )

CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - POWER SOURCE CONTROL ECU)

Disconnect the H14 HV control ECU connector.
Disconnect the P6 power source control ECU connector.

Measure the voltage between the terminal of the HV control ECU connector or power source control ECU and body ground with the power switch turned OFF.

VOLTAGE CHECK

Tester Connection	Specified Condition
ST2 (H14-5) or STSW (P6-39) - Body ground	Below 1 V

Reconnect the power source control ECU connector.
Reconnect the HV control ECU connector.

Fig 2: Disconnecting H14 HV Control ECU Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig 3: Disconnecting P6 Power Source Control ECU Connector

OK: POWER SOURCE CONTROL ECU