Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Toyota >> 2017 >> Yaris iA Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Troubleshooting (2 Of 2) >> SFI System >> No. 23 A/C Does Not Work Sufficiently >> Procedure

No. 23 A/C Does Not Work Sufficiently: Procedure

  1. VERIFY ECM, COMBINATION METER AND AIR CONDITIONING AMPLIFIER DTC 
    1. Retrieve the ECM, combination meter and air conditioning amplifier DTCs using the Techstream.

      Refer to ON-BOARD DIAGNOSTIC TEST

      Refer to DTC CHECK / CLEAR

    2. Are any DTCs present?

      Result

      Result
      Yes
      No

    Result:  2

    Yes 

    GO TO THE APPLICABLE DTC INSPECTION. 

    1. Refer to DIAGNOSTIC TROUBLE CODE CHART
    2. Refer to DIAGNOSTIC TROUBLE CODE CHART

    Result:  1

    No 

    See step  2

  2. DETERMINE IF MALFUNCTION CAUSE IS A/C RELAY CONTROL SIGNAL OR A/C REQUEST SIGNAL 
    1. Access the ECM PID Air conditioning compressor cycling switch using the Techstream.

      Refer to ON-BOARD DIAGNOSTIC TEST

    2. Start the engine and idle it.
    3. Turn the Air conditioning compressor cycling switch PID to True from False using the Techstream simulation function.
    4. Is the magnetic clutch engaged?

      Result

      Result
      Yes
      No

    Result:  2

    No 

    See step  8

    Result:  1

    Yes 

    See step  3

  3. DETERMINE IF MALFUNCTION CAUSE IS REFRIGERANT PRESSURE SENSOR OR OTHER 
    1. Access the ECM PID A/C Request Signal using the Techstream.

      Refer to ON-BOARD DIAGNOSTIC TEST

    2. Monitor the A/C Request Signal PID while turning Yes(True) and No(False) the air conditioner using the switch on the control panel.
    3. Is the A/C Request Signal PID value normal?

      Refer to INSPECTION

      Result

      Result
      Yes
      No

    Result:  2

    No 

    See step  5

    Result:  1

    Yes 

    See step  4

  4. INSPECT REFRIGERANT PRESSURE SENSOR 
    1. Inspect the refrigerant pressure sensor.

      Refer to INSPECTION

    2. Is there any malfunction?

      Result

      Result
      Yes
      No

    Result:  1

    No 

    INSPECT THE FOLLOWING: 

    1. Inspect the following:
      1. Refrigerant charging amount
      2. A/C compressor seized
    2. Repair or replace the malfunctioning part according to the inspection results if necessary.

    Result:  2

    Yes 

    REPAIR OR REPLACE THE MALFUNCTIONING PART ACCORDING TO THE INSPECTION RESULTS. 

  5. DETERMINE IF MALFUNCTION CAUSE IS EVAPORATOR TEMPERATURE SENSOR OR OTHER 
    1. Measure the voltage at the combination meter terminal D58-8 (wiring harness-side).
    2. Is the voltage normal?

      Refer to INSPECTION

      Result

      Result
      Yes
      No

    Result:  2

    Yes 

    See step  7

    Result:  1

    No 

    See step  6

  6. INSPECT EVAPORATOR TEMPERATURE SENSOR 
    1. Inspect the evaporator temperature sensor.

      Refer to INSPECTION

    2. Is there any malfunction?

      Result

      Result
      Yes
      No

    Result:  1

    No 

    INSPECT FOR A SHORT OR OPEN CIRCUIT BETWEEN THE FOLLOWING TERMINALS: 

    1. Evaporator temperature sensor terminal D17-2-Combination meter terminal D58-8
    2. Evaporator temperature sensor terminal D17-1-Combination meter terminal D58-16

      If there is any malfunction: 

      • Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
        • Evaporator temperature sensor terminal D17-2-Combination meter terminal D58-8
        • Evaporator temperature sensor terminal D17-1-Combination meter terminal D58-16

        If there is a common connector: 

        • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short or open circuit.
        • Repair or replace the malfunctioning part.

        If there is no common connector: 

        • Repair or replace the wiring harness which has a short or open circuit.

    Result:  2

    Yes 

    REPLACE THE EVAPORATOR TEMPERATURE SENSOR. 

    1. Refer to REMOVAL
  7. DETERMINE IF MALFUNCTION CAUSE IS COMBINATION METER OR OTHER 
    1. Verify the information display indication of A/C system while turning on and off the air conditioner using the switch on the control panel.
    2. Does the information display indicate properly?

      Result

      Result
      Yes
      No

    Result:  1

    No 

    A/C SWITCH MALFUNCTION, OR AIR CONDITIONING AMPLIFIER CANNOT DETERMINE THE A/C REQUEST OR TRANSMIT THE A/C REQUEST SIGNAL. 

    1. Replace the air conditioning amplifier.

      Refer to INSPECTION

    Result:  2

    Yes 

    COMBINATION METER DOES NOT RECEIVE THE A/C REQUEST SIGNAL FROM AIR CONDITIONING AMPLIFIER OR TRANSMIT IT TO ECM. 

    1. Replace the combination meter.

      Refer to REMOVAL

  8. DETERMINE IF MALFUNCTION CAUSE IS A/C CONTROL SIGNAL OR MAGNETIC CLUTCH 
    1. Start the engine and idle it.
    2. Access the ECM PID Air conditioning compressor cycling switch using the Techstream.

      Refer to ON-BOARD DIAGNOSTIC TEST

    3. Turn the Air conditioning compressor cycling switch PID to True from False using the Techstream simulation function.
    4. Measure the voltage at the magnetic clutch terminal C25-1 (wiring harness-side).
    5. Is the voltage 10.5 V or more?

      Result

      Result
      Yes
      No

    Result:  2

    No 

    See step  10

    Result:  1

    Yes 

    See step  9

  9. INSPECT IF MALFUNCTION CAUSE IS MAGNETIC CLUTCH OR MAGNETIC CLUTCH GROUND CIRCUIT 
    1. Switch the ignition off.
    2. Disconnect the magnetic clutch connector.
    3. Inspect for continuity between magnetic clutch terminal C25-1 (part-side) and body ground.
    4. Is there continuity?

      Result

      Result
      Yes
      No

    Result:  1

    No 

    INSPECT THE A/C COMPRESSOR. (POOR CONTACT TO GROUND) 

    1. If there is any malfunction:
      1. Repair or replace the malfunctioning part according to the inspection results.
    2. If there is no malfunction:
      1. Replace the A/C compressor. (internal circuit open)

    Result:  2

    Yes 

    INSPECT THE MAGNETIC CLUTCH. 

    1. Refer to INSPECTION
    2. Replace the magnetic clutch if necessary.
  10. INSPECT A/C RELAY 
    1. Switch the ignition off.
    2. Remove the A/C relay.
    3. Inspect the A/C relay.

      Refer to INSPECTION

    4. Is there any malfunction?

      Result

      Result
      Yes
      No

    Result:  2

    Yes 

    REPLACE THE A/C RELAY. 

    Result:  1

    No 

    See step  11

  11. INSPECT A/C RELAY CONTROL CIRCUIT FOR OPEN CIRCUIT 
    1. A/C relay is removed.
    2. Disconnect the ECM connector.
    3. Inspect for continuity between A/C relay terminal 1 (wiring harness-side) and ECM terminal A42-21 (wiring harness-side).
    4. Is there continuity?

      Result

      Result
      Yes
      No

    Result:  1

    No 

    REFER TO THE WIRING DIAGRAM AND VERIFY WHETHER OR NOT THERE IS A COMMON CONNECTOR BETWEEN A/C RELAY TERMINAL 1 AND ECM TERMINAL A42-21. 

    If there is a common connector: 

    • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
    • Repair or replace the malfunctioning part.

    If there is no common connector: 

    • Repair or replace the wiring harness which has an open circuit.

    Result:  2

    Yes 

    INSPECT FOR CONTINUITY BETWEEN THE FOLLOWING: 

    1. Inspect for continuity between the following:
      1. IG1 relay terminal 5-A/C relay terminal 2
      2. Battery positive terminal-A/C relay terminal 5
      3. A/C relay terminal 3-Magnetic clutch terminal C25-1
    2. Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
      1. IG1 relay terminal 5-A/C relay terminal 2
      2. Battery positive terminal-A/C relay terminal 5
      3. A/C relay terminal 3-Magnetic clutch terminal C25-1

      If there is a common connector: 

      • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
      • Repair or replace the malfunctioning part.

      If there is no common connector: 

      • Repair or replace the wiring harness which has an open circuit.
scientia non olet · About Mike's Workshop Manuals