Terminals Of Ecu

CHECK HEATER CONTROL

Fig 1: Identifying Heater Control ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the voltage and resistance according to the value(s) in the table below.

Standard voltage:

TERMINALS VOLTAGE REFERENCE

Terminal No. (Symbols)	Wiring Color	Terminal Description	Condition	Specified Condition
C40-2 (RDEF) - C40-5 (E)	B - W-B	Rear defogger signal	Ignition switch ON, Rear defogger switch OFF	11 to 14 V
C40-2 (RDEF) - C40-5 (E)	B - W-B	Rear defogger signal	Ignition switch ON, Rear defogger switch ON	Below 1 V
C40-3 (IG+) - C40-5 (E)	Y - W-B	Power source	Ignition switch ON	11 to 14 V
C40-3 (IG+) - C40-5 (E)	Y - W-B	Power source	Ignition switch OFF	Below 1 V

Standard resistance:

TERMINALS RESISTANCE REFERENCE

Terminal No. (Symbols)	Wiring Color	Terminal Description	Condition	Specified Condition
C40-5 (E) - Body ground	W-B - Body ground	Ground	Always	Below 1 Ω

If the result is not as specified, there may be a malfunction in the wire harness.

CHECK MAIN BODY ECU

Fig 2: Identifying Main Body ECU Connector Terminals

Measure the voltage according to the value(s) in the table below.

Standard voltage:

TERMINALS VOLTAGE REFERENCE

Terminal No. (Symbols)	Wiring Color	Terminal Description	Condition	Specified Condition
2G-1 - Body ground	W - Body ground	Power source	Always	11 to 14 V
2Q-12 - Body ground	B - Body ground	DEF Relay operation signal	Ignition switch ON, Rear defogger switch OFF	11 to 14 V
2Q-12 - Body ground	B - Body ground	DEF Relay operation signal	Ignition switch ON, Rear defogger switch ON	Below 1 V
2F-2 - Body ground	B - Body ground	Defogger wire operation signal	Ignition switch ON, Rear defogger switch OFF	Below 1 V
2F-2 - Body ground	B - Body ground	Defogger wire operation signal	Ignition switch ON, Rear defogger switch ON	11 to 14 V

If the result is not as specified, there may be a malfunction in the wire harness or main body ECU.