INSPECTION
PROCEDURE 2: Cool air does not come
|
|
If the blower air temperature can not be cool when turning A/C switch ON and
lowering the preset temperature, inadequate refrigerant quantity, sensors, harness or connectors
may be suspected.
|
|
|
- The refrigerant quantity is inadequate.
- Damaged harness wires and connectors
- Malfunction of the blower motor
- Malfunction of the fin thermo sensor
- Malfunction of the heater controller assembly (A/C-ECU)
- Malfunction of the engine-ECU
- Malfunction of the dual pressure switch
- Malfunction of the A/C compressor and clutch
|
|
|
STEP 1. M.U.T.-III CAN bus diagnostics.
|
|
|
Use the M.U.T.-III to diagnose the CAN bus lines.
|
|
|
Q.
Is the check result normal?
|
|
|
 Go to Step 2.
|
|
|
|
|
|
 Repair the CAN bus lines. (Refer to GROUP 54C - Troubleshooting  ).
|
|
|
|
|
|
STEP 2. M.U.T.-III diagnosis code for heater controller assembly (A/C-ECU).
|
|
|
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. Check the M.U.T.-III diagnosis code for engine-ECU.
|
|
|
Check whether the engine-ECU sets any of the diagnosis codes below:
|
|
|
P0537: Air thermo sensor circuit low input
P0538: Air thermo sensor circuit high input
|
|
|
Q.
Is the diagnosis code set?
|
|
|
YES <4G6> : Carry out the diagnosis code procedures (Refer to GROUP 13A - Code No.
P0537: Air thermo sensor circuit low input <A/C>,
Code No. P0538: Air thermo sensor circuit high Input <A/C>).
|
|
|
|
|
|
YES <4D5> : Carry out the diagnosis code procedures (Refer to GROUP 13B - Code No.
P0537: Air thermo sensor circuit low input , Code No. P0538:
Air thermo sensor circuit high Input ).
|
|
|
|
|
|
YES <4N1> : Carry out the diagnosis code procedures (Refer to GROUP 13C - Code No.
P0537: Air thermo sensor circuit low input , Code No. P0538:
Air thermo sensor circuit high Input ).
|
|
|
|
|
|
Go to Step 4.
|
|
|
|
|
|
STEP 4. Check the blower operation.
|
|
|
Check that air blows through the air outlets.
|
|
|
(1)Turn the ignition switch to the ON position.
|
|
|
(2)Air volume adjusting knob: Other than OFF
|
|
|
(3)Check that the air comes out of the blower.
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 5.
|
|
|
|
|
|
Refer to Inspection Procedure 3 "The blower does not work" .
|
|
|
|
|
|
STEP 5. Check the A/C compressor operation.
|
|
|
Check that the compressor operates under the following conditions.
|
|
|
- Engine operation
- Air volume adjusting knob: Maximum air volume
- Temperature adjusting knob: MAX COOL
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 6.
|
|
|
|
|
|
Refer to Inspection Procedure 8 "The A/C compressor and clutch assembly
does not work" .
|
|
|
|
|
|
STEP 6. Refrigerant level check.
|
|
|
Check that the refrigerant level is adequate (Refer to GROUP 55A -Refrigerant
level check, draining and charging ).
|
|
|
Q.
Is the check result normal?
|
|
|
YES  : Go to Step 7.
|
|
|
|
|
|
Correct the refrigerant amount.
|
|
|
|
|
|
STEP 7. Check the dual pressure switch.
|
|
|
Refer to GROUP 55A - Pressure switch check .
|
|
|
Q.
Is the dual pressure switch in good condition?
|
|
|
Go to Step 8.
|
|
|
|
|
|
Replace the dual pressure switch (Refer to GROUP 55A - Refrigerant Line ).
|
|
|
|
|
|
STEP 8. Voltage measurement at dual pressure switch connector.
|
|
|
(1)Disconnect the connector, and measure at the wiring harness side.
|
|
|
(2)Turn the ignition switch to the "ON" position.
|
|
|
(3)Voltage between terminal 1 and body earth.
OK: System voltage
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 10.
|
|
|
|
|
|
Go to Step 9.
|
|
|
|
|
|
STEP 9. Check of open circuit in dual pressure switch line between
dual pressure switch connector AC/S terminal and engine-ECU connector.
|
|
|
Q.
Is the check result normal?
|
|
|
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent
Malfunction ).
|
|
|
|
|
|
Repair or replace the connector(s) or wiring harness.
|
|
|
|
|
|
STEP 10. Voltage measurement at heater control panel.
|
|
|
(1)Disconnect the connector, and measure at the wiring harness side.
|
|
|
(2)Turn the ignition switch to the "ON" position.
|
|
|
(3)Voltage between terminal 10 and body earth.
OK: System voltage
|
|
|
Q.
Is the check result normal?
|
|
|
Go to Step 12.
|
|
|
|
|
|
Go to Step 11.
|
|
|
|
|
|
STEP 11. Check of open circuit in dual pressure switch line heater
control panel (A/C-ECU) connector A/C terminal and dual pressure switch connector.
|
|
|
Q.
Is the check result normal?
|
|
|
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent
Malfunction ).
|
|
|
|
|
|
Repair or replace the connector(s) or wiring harness.
|
|
|
|
|
|
STEP 12. Retest the system
|
|
|
Q.
Is the check result normal?
|
|
|
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent
Malfunction ).
|
|
|
|
|
|
NO <4G6> : Replace the engine-ECU (Refer to GROUP 13A - Engine-ECU ).
Then go to Step 13.
|
|
|
|
|
|
NO <4D5> : Replace the engine-ECU (Refer to GROUP 13B - Engine-ECU ).
Then go to Step 13.
|
|
|
|
|
|
NO <4N1> : Replace the engine-ECU (Refer to GROUP 13C - Engine-ECU ).
Then go to Step 13.
|
|
|
|
|
|
STEP 13. Retest the system
|
|
|
Q.
Is the check result normal?
|
|
|
This diagnosis is complete.
|
|
|
|
|
|
Replace the heater controller assembly (A/C-ECU) (Refer to ).
|
|
|
|