Compressor Control (A/C Relay Signal) Inspection

Compressor Control (A/C Relay Signal) Inspection

VB: Battery voltage:

Step 1
Idle-up control operation check
1. Turn the ignition switch ON and press the AUTO switch ON.
2. Press the DEF switch ON and set the blower switch at manual 1st speed. Verify that the engine speed increases.
3. If the idle-up control operates, go to Step 2.
4. If the idle-up control does not operate, go to Step 9.

Step 2
Fuse inspection







1. Check the indicated fuses.
2. If a fuse is burnt, replace it after checking and repairing the wiring harness as necessary.
3. If the fuses are OK, go to Step 3.

Step 3
A/C relay connector terminal voltage inspection





1. Remove the A/C relay.
2. Turn the ignition switch ON and press the AUTO switch ON.





3. Measure voltage at terminal wires (R) and (R/W) of the A/C relay connector in the relay box.

Step 4
A/C relay inspection
1. Remove the A/C relay.





2. Connect battery positive voltage to the terminal b and ground the terminal c of the relay.





3. Check continuity between terminals a and b of the relay.

Step 5
A/C relay operation inspection





1. Connect a jumper wire between terminal wire L/W and a body ground.
2. Turn the ignition switch ON, and turn the AUTO switch ON.
3. If the compressor operates, repair the wiring harness and/or check the ECU.
4. If the compressor does not operate, go to Step 6.

Step 6
1. Disconnect the refrigerant pressure switch connector.





2. Connect a jumper wire between terminals of the connector as shown.
3. Turn the ignition switch ON and press the AUTO switch ON.
4. Set the temperature at 18°C (64°F}.
5. If the compressor operates, measure the refrigerant pressure.
If the pressure is normal, replace the refrigerant pressure switch.
6. If the compressor does not operate, go to Step 7.

Step 7
Refrigerant pressure switch connector voltage inspection
1. Disconnect the refrigerant pressure switch connector.
2. Turn the ignition switch ON, and turn the AUTO switch ON.
3. Set the temperature at 18°C (64°F}.








4. Measure voltage at terminal wire (LG) of the connector.


Step 8
Magnetic clutch terminal voltage inspection
1. Turn the ignition switch ON, and turn the AUTO switch ON.
2. Set the temperature at 18°C (64°F).








3. Measure the voltage at terminal wire of the magnetic clutch connector.


Step 9
A/C amplifier connector terminal voltage Inspection
1. Turn the ignition switch ON, and turn the AUTO switch ON.
2. Set the temperature at 18°C (64°F}.








3. Measure the voltage at terminal wire (B/O) of the A/C amplifier connector.