Toyota Corolla (E120) 2002–2008 Repair Manual / Heater & air conditioner / Air conditioning system / On–vehicle inspection
Toyota Corolla (E120): On–vehicle inspection
1. Inspect pressure switch no.1.

- Magnetic clutch control: inspect pressure switch operation.
- Set on the manifold gauge set.
- Connect the positive (+) lead from the ohmmeter to terminal 4 and the negative (–) lead to terminal 1.
- Check continuity between terminals when refrigerant pressure is changed, as shown in the illustration.
If operation is not as specified, replace the pressure switch.

- Cooling fan control: inspect pressure switch operation.
- Connect the positive (+) lead from the ohmmeter to terminal 2 and the negative (–) lead to terminal 3.
- Check continuity between terminals when refrigerant pressure is changed, as shown in the illustration.
If operation is not as specified, replace the pressure switch.
2. Cooler compressor assy w/magnetic clutch
- connect the positive (+) lead from the battery to terminal and the negative (–) lead to the body ground.
- check that the magnetic clutch energized.
If operation is not as specified, replace the magnet clutch assy.
Other materials:
Terminals of ecu
Oscilloscope wave (*1)
Hint:
terminal: od – gnd
gauge set: 5 v / div, 50 ms / div
condition: during cruise control driving o/d switch on.
...
Inspection procedure
Hint:
troubleshoot each trouble symptom in accordance with the chart below.
1 Clear dtc
Connect the hand–held tester or the obd ii scan tool to the dlc 3.
turn the ignition switch on and push the hand–held tester or the
obd ii scan tool main switch on.
read the dtc . ...
Diagnosis system
Description
when troubleshooting obd ii vehicles, the only difference
from the usual troubleshooting procedure
is that you need to connect an obd ii scan tool complying
with sae j1987 or a hand–held tester to the
vehicle, and read off various data output from the
vehicle†...


