Inspection Procedure 7

INSPECTION PROCEDURE 7: The A/C Indicator Flashes

Ambient Air Temperature Sensor And A/C Pressure Sensor Circuit Part 1:

CIRCUIT OPERATION
If the A/C indicator flashes, inadequate refrigerant quantity, the ambient air temperature sensor circuit or the A/C pressure sensor circuit is suspected.

TROUBLESHOOTING HINTS
- Malfunction of the A/C pressure sensor
- Malfunction of the ambient air temperature sensor
- Malfunction of the A/C-ECU


DIAGNOSIS

STEP 1. Check the A/C pressure sensor operation.




1. Assemble a manifold gauge onto the high pressure service valve.
2. Turn ON the engine and then turn ON the air conditioner switch.
3. At this time, check to see that the voltage between the A/C pressure sensor terminal No. 2 and body ground reflects the specifications of the Figure.

NOTE: The allowance shall be defined as 5%.

Q: Is the A/C pressure sensor operating properly?

YES: Go to Step 2.

NO: Replace the A/C pressure sensor.

STEP 2. Check the ambient air temperature sensor.

Q: Is the ambient air temperature sensor in good condition?

YES: Go to Step 3.

NO: Replace the ambient air temperature sensor.

STEP 3. Check the refrigerant level. Refer to On-vehicle service - sight glass refrigerant level test in Heating and Air Conditioning.

Q: Is the refrigerant level correct?

YES: Replace the A/C-ECU.

NO: Correct the refrigerant level. (Refer to On-vehicle Service in Heating and Air Conditioning). Check that the air conditioning works normally.