Inspection Procedure 7
THE A/C INDICATOR FLASHES.A/C Pressure Sensor Circuit:
CIRCUIT OPERATION
If the A/C indicator flashes then the possible causes may be due to a defective A/C pressure system or insufficient refrigerant gas.
TROUBLESHOOTING HINTS
- Malfunction of the A/C pressure sensor
- Malfunction of the A/C-ECU
Required Special Tools:
- MB991223: Test Harness Set
STEP 1. Check the refrigerant level.
Q: Is the refrigerant level correct?
YES: Go to Step 2.
NO: Correct the refrigerant level. (Refer to On-vehicle Service.) Check that the air conditioning works normally.
STEP 2. 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 3.
NO: Replace the A/C pressure sensor. Check that the air conditioning works normally.
STEP 3. Check A/C pressure sensor connector A-02 and A/C-ECU connector C-06 for damage.
Q: Is A/C pressure sensor connector A-02 and A/C-ECU connector C-06 in good condition?
YES: Go to Step 4.
NO: Repair or replace the connector. Refer to Harness Connector Inspection. Check that the air conditioning works normally.
STEP 4. Check the wiring harness between A/C pressure sensor connector A-02 (terminal 2) and A/C-ECU connector C-06 (terminal 15).
NOTE: Also check intermediate connector C-116. If intermediate connector C-116 is damaged, repair or replace the connector as described in Harness Connector Inspection.
Q: Is the wiring harness between A/C pressure sensor connector A-02 (terminal 2) and A/C-ECU connector C-06 (terminal 15) in good condition?
YES: Check that the air conditioning works normally.
NO: Repair the wiring harness. Check that the air conditioning works normally.