On-Vehicle Inspection

WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.

CHECK PRESSURE SWITCH

Disconnect the switch connector.
Set the manifold gauge.
Turn the ignition switch ON.

Measure the resistance of the switch.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
1 - 4	Refrigerant pressure is changed (Low and high pressure side) (Refer to illustration)	Resistance is changed (Low and high pressure side) (Refer to illustration)
2 - 3	Refrigerant pressure is changed (Middle pressure side) (Refer to illustration)	Resistance is changed (Middle pressure side) (Refer to illustration)

Fig 1: Identifying Pressure Switch Connector

G05291849

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Resistance Chart

G05291850

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT RELAY (Marking: IG1, HTR)

Measure the resistance of the relay.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Specified Condition
3 - 5	10 Ω or higher
3 - 5	Below 1 Ω (when battery voltage is applied to terminals 1 and 2)

If the result is not as specified, replace the relay.

Fig 3: Inspecting Relay (Marking: IG1, HTR)

G05291851

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

INSPECT RELAY (Marking: ACC, A/C COMP)

Measure the resistance of the relay.

Standard resistance

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Specified Condition
3 - 5	10 Ω or higher
3 - 5	Below 1 Ω (when battery voltage is applied to terminals 1 and 2)

If the result is not as specified, replace the relay.

Fig 4: Inspecting Relay (Marking: ACC, A/C COMP)

G05291852

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002