INSPECTION PROCEDURE 10: A/C outlet air temperature cannot be set








COMMENTS ON TROUBLE SYMPTOM
If the air conditioner outlet temperature cannot be adjusted, the air mixing damper control motor or the A/C-ECU may be faulty.
note It cannot be adjusted while the engine coolant temperature is low.

PROBABLE CAUSES

  • Malfunction of air mix damper control motor
  • Malfunction of A/C-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Check the compressor operation
Check that the compressor operates under the following conditions.

  • Engine operation
  • Air volume control dial: Maximum
  • Air conditioner switch: ON
  • Temperature control dial: 18°C (MAX COOL)

Q. Is the check result normal?
Go to Step 2.
Refer to INSPECTION PROCEDURE 6: "The A/C compressor does not work", .

STEP 2. M.U.T.-III diagnosis code
Check that the diagnosis code related to the air conditioner is not set.

Q. Is the diagnosis code set?
Carry out the diagnosis code procedures. Refer to .
Go to Step 3.

STEP 3. M.U.T.-III actuator test
Carry out the actuator test. (Refer to ).

  • Item 06: air mixing damper control motor (Select "position reset").

Q. Is the check result normal?
This diagnosis is complete.
Go to Step 4.

STEP 4. Connector check: C-116 air mixing damper control motor connector, C-110 A/C-ECU connector

Q. Is the check result normal?
Go to Step 5.
Repair the connector concerned.

STEP 5. Check the wiring harness wires between C-116 air mixing damper control motor connector (terminals 3, 2, 5, 4 and 1) and C-110 A/C-ECU connector (terminals 29, 36, 35, 34 and 28).

  • Check the input line for open circuit.

Q. Is the check result normal?
Go to Step 6.
Repair the wiring harness.

STEP 6. Replace the air mixing damper control motor, and recheck the trouble symptom.
Check that A/C outlet air temperature can be adjusted.
note Whenever the motor is replaced, initialise the motor position by using the Actuator Test.

Q. Is the check result normal?
This diagnosis is complete.
Replace the A/C-ECU.