Inspection Procedure

WARNING: This page is about a different car, the 2002 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.

Check voltage between terminal MGC of integration control and panel and body ground
Check:
1. Start engine.
2. Push AUTO SW.
3. Measure voltage between terminal MGC of integration control and panel connector and body ground when A/C switch is ON and OFF.
OK:

Fig 1: A/c Switch Voltage Specifications
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: Locating Integration Control And Panel Connector MCG Terminal
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. OK: Go to step 5 .
Check Magnetic Clutch Relay
Preparation:

Remove magnetic clutch relay from engine room J/B.

Check:

Check continuity between each pair of terminals shown below of magnetic clutch relay.

OK:

Fig 3: Magnetic Clutch Relay Resistance Specifications
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 4: Testing Magnetic Clutch Relay
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Preparation:

Apply battery positive (+) voltage between terminals 1 and 2.

Check:

Check continuity between terminals 3 and 5.

OK:

Continuity exists.
1. NG: Replace magnetic clutch relay.
2. OK: Go to next step.
Check A/C Magnetic Clutch
Preparation:

Disconnect magnetic clutch connector.

Check:

Connect positive (+) lead connected to battery to magnetic clutch connector terminal 3.

OK:

Magnetic clutch is energized.

Fig 5: Energizing Magnetic Clutch
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Repair A/C magnetic clutch.
2. OK: Go to next step.
Check Harness And Connector Between Magnetic Clutch Relay And Integration Control And Panel, A/C Compressor And Body Ground
1. NG: Repair or replace harness or connector.
2. OK: Proceed to next circuit inspection shown on problem symptoms table. See PROBLEM SYMPTOMS TABLE .
Check Voltage Between Terminal Integration Control And Panel Connector Side And Body Ground
Preparation:
1. Disconnect integration control and panel connector.
2. Turn ignition switch ON.
Check:

Check voltage between terminal AC1 of A/C control assembly harness side connector.

OK:

Voltage: 10 - 14 V

Fig 6: Locating A/C Control AC1 Terminal & Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Check and replace ECM.
2. OK: Go to next step.
Check Voltage Between Terminal AC1 Of Integration Control And Panel Connector And Body Ground
Preparation:
1. Remove integration control and panel with connector still connected.
2. Start the engine and push AUTO switch.
Check:

Check the voltage between terminal AC1 of integration control and panel connector and body ground when magnetic clutch is ON and OFF by A/C switch.

OK:

Fig 7: Magnetic Clutch Voltage Specifications
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 8: Locating Integration Control And Panel Connector AC1 Terminal
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Check and replace integration control and panel.
2. OK: Go to next step.
Check Voltage Between Terminal Act Of Integration Control And Panel And Body Ground
Preparation:
1. Remove integration control and panel with connectors still connected.
2. Start the engine and push AUTO switch.
Check:

Check the voltage between terminal ACIN of A/C control assembly and body ground.

OK:

Fig 9: Magnetic Clutch Voltage Specification
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 10: Locating Integration Control And Panel ACT Terminal
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NG: Check and replace integration control and panel.
2. OK: Go to next step.
Check Voltage Between Terminal ACT Of ECM Connector And Body Ground
1. NG: Check and replace ECM.
2. OK: Go to next step.
Check Harness And Connector Between Integration Control And Panel And ECM
1. NG: Repair or replace harness or connector.
2. OK: Proceed to next circuit inspection shown on problem symptoms table. See PROBLEM SYMPTOMS TABLE .