Inspection Procedure

WARNING: This page is about a different car, the 2004 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.

READ VALUE OF HAND-HELD TESTER

Connect the hand-held tester to the DLC3.
Turn the ignition switch ON and push the hand-held tester main SW ON.
Check the A/C magnet clutch input signal using DATA LIST.

ECM

Description	Tester display	Check condition
Magnet clutch inputsignal	A/C SIG	ON-OFF

NG: Go to step 7

OK: Go To Next Step.

INSPECT COOLER RELAY ASSY

Remove the cooler relay assy from the engine room J/B.

Fig 1: Inspecting Cooler Relay Assy

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Check continuity between each pair of terminals as shown in the chart.

STANDARD

Tester connection	Specified condition
1-2	Continuity
3-5	No continuity

Apply battery voltage between terminal 1 and 2.
Check that continuity exists between terminal 3 and 5.
Standard: Continuity exists.

NG: REPLACE COOLER RELAY ASSY

OK: Go To Next Step.

READ VALUE OF HAND-HELD TESTER

Connect the hand-held tester to DLC3.
Turn the ignition switch ON and push the hand-held tester main SW ON.
Check the A/C magnet clutch using DATA LIST.

ECM

Description	Tester display	Check condition
Magnet clutch outputsignal	A/C MAG CLUTCH	ON-OFF

NG: Go to step 9

OK: Go To Next Step.

INSPECT MAGNET CLUTCH ASSY
1. Disconnect the connector from the compressor.
2. Connect the battery positive (+) lead to terminal 3 and the battery negative (-) lead to terminal body ground, then check that the magnetic clutch is engaged.
  
  Fig 2: Inspecting Magnet Clutch Assy
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Standard: Magnetic clutch is engaged.
NG: REPLACE MAGNET CLUTCH ASSY

OK: Go To Next Step.
CHECK HARNESS AND CONNECTOR (BETWEEN BATTERY AND COOLER RELAY ASSY)
1. Remove the cooler relay assy from the engine room R/B.
2. Turn the ignition switch to ON.
3. Measure voltage between terminal 5, 6 of the engine room J/B and body ground.
  Voltage: 10-14 V
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go To Next Step.
CHECK HARNESS AND CONNECTOR (BETWEEN COOLER RELAY ASSY AND BODY GROUND)
1. Remove the cooler relay assy from the engine room R/B.
2. Measure resistance between terminal 3 of the engine room R/B and body ground.
  Resistance: Below 1.0 Ω (Continuity)
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS TABLE , refer to PROBLEM SYMPTOMS TABLE

INSPECT AIR CONDITIONING AMPLIFIER (ACS, THE)

Remove the A/C amplifier with the connectors being connected.
Start the engine and push AUTO switch.
Measure voltage between terminal THE and ACS of the A/C amplifier and body ground when the magnetic clutch is turned ON and OFF by operating the A/C switch.

Fig 5: Inspecting Air Conditioning Amplifier (ACS, THE)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Voltage:

VOLTAGE CHECK

Switch operation	Tester connection	Specified condition
ON	THE-Body ground	1.3-2.6V
OFF	THE-Body ground	3.7-4.5 V
ON	ACS-Body ground	10-14 V
OFF	ACS-Body ground	Below 1 V

NG: CHECK AND REPLACE AIR CONDITIONING AMPLIFIER

OK: Go To Next Step.

CHECK HARNESS AND CONNECTOR
1. Check for open and short circuit in the harness and the connector between ECM and the A/C amplifier (See ELECTRONIC CIRCUIT INSPECTION PROCEDURE ).
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: CHECK AND REPLACE ECM
CHECK HARNESS AND CONNECTOR
1. Disconnect the "E7" connector from ECM.
2. Turn the ignition switch to ON.
3. Measure voltage between terminal ACMG of ECM and body ground.
  
  Fig 6: Measuring Voltage Between Terminal ACMG Of ECM And Body Ground
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Voltage: 10-14 V
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: CHECK AND REPLACE ECM