NO.23 A/C DOES NOT WORK SUFFICIENTLY [MZR 2.0 DISI i-stop]

id0103d3802900

23

A/C DOES NOT WORK SUFFICIENTLY
DESCRIPTION
•  A/C compressor magnetic clutch does not engage when A/C switch is turned on.
POSSIBLE CAUSE
•  PCM, instrument cluster, multi information display or climate control unit (full-auto air conditioner) DTC is stored.
•  Refrigerant pressure sensor malfunction
•  Improper refrigerant charging amount
•  Seized A/C compressor
•  Evaporator temperature sensor malfunction
•  Open or short circuit in wiring harness between the following terminals:
―  Evaporator temperature sensor terminal B—Climate control unit terminal 1L
―  Evaporator temperature sensor terminal A—Climate control unit terminal 1E
•  Instrument cluster malfunction (Does not receive A/C request switch from climate control unit or transmit it to PCM)
•  Multi information display malfunction
•  Climate control unit malfunction (A/C switch malfunction or climate control unit does not determine A/C request or transmit A/C request signal)
•  Open circuit in wiring harness between magnetic clutch and body ground
•  A/C relay stuck open
•  Open circuit in wiring harness between the following:
―  Ignition switch (IG2)—A/C relay terminal A (vehicles without advanced keyless entry and push button start system)
―  IG2 relay—A/C relay terminal A (vehicles with advanced keyless entry and push button start system)
―  Main battery positive terminal—A/C relay terminal C
―  A/C relay terminal D—Magnetic clutch terminal A
•  Open circuit in wiring harness between A/C relay terminal E and PCM terminal 1I

*1  :Vehicles without advanced keyless entry and push button start system
*2  :Vehicles with advanced keyless entry and push button start system

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
Connect the M-MDS to the DLC-2.
Retrieve the PCM, instrument cluster, multi information display and climate control unit (full-auto air conditioner) DTCs using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 2.0 DISI i-stop].)
(See DTC INSPECTION [INSTRUMENT CLUSTER].)
(See DTC INSPECTION [INFORMATION DISPLAY/MULTI INFORMATION DISPLAY].)
(See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].)
Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZR 2.0 DISI i-stop].)
(See DTC TABLE [INSTRUMENT CLUSTER].)
(See DTC TABLE [INFORMATION DISPLAY/MULTI INFORMATION DISPLAY].)
(See DTC TABLE [FULL-AUTO AIR CONDITIONER].)
No
Go to the next step.
2
Access the PCM PID ACCS using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 2.0 DISI i-stop].)
Start the engine and idle it.
Turn the ACCS PID to ON from OFF using the M-MDS simulation function.
Is the magnetic clutch engaged?
Yes
Go to the next step.
No
Go to Step 9.
3
Access the climate control unit PID AC_PRES using the M-MDS.
(See PID/DATA MONITOR DISPLAY [FULL-AUTO AIR CONDITIONER].)
Monitor the AC_PRES PID while turning on and off the air conditioner by switching the control panel.
Is the PID value normal?
(See PID/DATA MONITOR TABLE [FULL-AUTO AIR CONDITIONER].)
Yes
Go to Step 5.
No
Go to the next step.
4
Inspect the refrigerant pressure sensor.
(See REFRIGERANT PRESSURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].)
Is there any malfunction?
Yes
Repair or replace the malfunctioning parts according to the inspection results.
No
Inspect for the following:
•  Refrigerant charging amount
•  A/C compressor seized
Repair or replace the malfunctioning parts according to the inspection results if necessary.
5
Access the climate control unit PID EVAP_TEMP using the M-MDS.
(See PID/DATA MONITOR DISPLAY [FULL-AUTO AIR CONDITIONER].)
Monitor the EVAP_TEMP PID while turning on and off the air conditioner by switching the control panel.
Is the PID value normal?
(See PID/DATA MONITOR TABLE [FULL-AUTO AIR CONDITIONER].)
Yes
Go to Step 7.
No
Go to the next step.
6
Inspect the evaporator temperature sensor.
(See EVAPORATOR TEMPERATURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].)
Is there any malfunction?
Yes
Replace the evaporator temperature sensor.
(See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
No
Inspect for open or short circuit between the following terminals:
•  Evaporator temperature sensor terminal B—Climate control unit terminal 1L
•  Evaporator temperature sensor terminal A—Climate control unit terminal 1E
Repair or replace the suspected wiring harness if necessary.
7
Verify the multi information display indication of A/C system while turning on and off the air conditioner by switching the control panel.
Does the multi information display indicate properly?
Yes
Instrument cluster does not receive the A/C request signal from the climate control unit or transmit it to the PCM.
•  Replace the instrument cluster.
No
Go to the next step.
8
Inspect the multi information display.
(See MULTI INFORMATION DISPLAY INSPECTION.)
Is there any malfunction?
Yes
Repair or replace the malfunctioning parts according to the inspection results.
No
A/C switch or fan switch malfunction, or climate control unit can not determine the A/C request or transmit it to the BCM.
•  Replace the climate control unit.
9
Start the engine and idle it.
Access the PCM PID ACCS using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [MZR 2.0 DISI i-stop].)
Turn the ACCS PID to ON from OFF using the M-MDS simulation function.
Measure the voltage at the magnetic clutch terminal A (wiring harness-side).
Is the voltage 10.5 V or more?
Yes
Go to the next step.
No
Go to Step 11.
10
Swtich the ignition to off.
Disconnect the magnetic clutch connector.
Inspect for continuity between magnetic clutch terminal A (part-side) and body ground.
Is there continuity?
Yes
Inspect the magnetic clutch.
(See MAGNETIC CLUTCH INSPECTION [FULL-AUTO AIR CONDITIONER].)
Replace the magnetic clutch if necessary.
No
Repair or replace the wiring harness for a possible open circuit and/or poor contact gruond point.
11
Inspect the A/C relay.
(See RELAY INSPECTION.)
Is there any malfunction?
Yes
Replace the A/C relay.
No
Go to the next step.
12
Switch the ignition to off.
Remove the A/C relay.
Disconnect the PCM connector.
Inspect for continuity between A/C relay terminal E (wiring harness-side) and PCM terminal 1I (wiring harness-side).
Is there continuity?
Yes
Inspect for continuity between the following:
•  Ignition switch (IG2)—A/C relay terminal A (vehicles without advanced keyless entry and push button start system)
•  IG2 relay—A/C relay terminal A (vehicles with advanced keyless entry and push button start system)
•  Main battery positive terminal—A/C relay terminal C
•  A/C relay terminal D—Magnetic clutch terminal A
Repair or replace the wiring harness for a possible open circuit.
No
Repair or replace the wiring harness for a possible open circuit.
13
Verify the test results.
•  If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.0 DISI i-stop].)
•  If a malfunction remains, inspect the related Service Information and perform the repair or diagnosis.
―  If the vehicle is repaired, troubleshooting is completed.
―  If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 2.0 DISI i-stop].)