NO.23 A/C DOES NOT WORK SUFFICIENTLY [MZR 2.3 DISI Turbo]
id0103e2802900
23 |
A/C DOES NOT WORK SUFFICIENTLY |
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DESCRIPTION
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• A/C compressor magnetic clutch does not engage when A/C is turned on.
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POSSIBLE CAUSE
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• PCM, climate control unit, instrument cluster or multi information display 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 evaporator temperature sensor and climate control unit (Full-auto air conditioner)
• Instrument cluster malfunction (Does not receive A/C request signal 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 the A/C request signal)
• Open or short circuit in wiring harness between climate control unit terminal 2P and instrument cluster terminal 2I (Manual air conditioner)
• A/C compressor malfunction
• Open circuit in wiring harness between A/C magnetic clutch terminal A and body ground
• A/C relay malfunction
• Open circuit in wiring harness between A/C relay and PCM terminal 1I
• Open circuit in wiring harness between ignition switch (IG2) and A/C relay (vehicles without advanced keyless entry and push button start system)
• Open circuit in wiring harness between IG2 relay and A/C relay (vehicles with advanced keyless entry and push button start system)
• Open circuit in wiring harness between battery positive terminal and A/C relay
• Open circuit in wiring harness between A/C relay and A/C magnetic clutch
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Diagnostic procedure
STEP |
INSPECTION |
RESULTS |
ACTION |
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1
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Perform the PCM, instrument cluster, climate control unit and multi information display DTC inspection using the M-MDS.
Are any DTCs present?
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Yes
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Go to the applicable DTC inspection.
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No
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Go to the next step.
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2
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Access the PCM PID ACCS using the M-MDS.
Start the engine and idle it.
Turn the ACCS PID to ON from OFF using the M-MDS simulation function.
Is the A/C magnetic clutch engaged?
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Yes
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Manual air conditioner:
• Go to Step 4.
Full-auto air conditioner:
• Go to the next step.
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No
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Go to Step 13.
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3
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Access the climate control unit PID AC_PRES using the M-MDS.
Monitor the climate control unit AC_PRES PID while turning on and off the air conditioner by switching the control panel.
Is the AC_PRES PID value normal?
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Yes
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Go to Step 6.
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No
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Go to Step 5.
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4
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Remove the climate control unit.
Reconnect the climate control unit connector.
Measure the voltage at the climate control unit terminal 1H (wiring harness-side).
Is the voltage normal?
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Yes
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Go to Step 7.
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No
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Go to the next step.
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5
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Inspect the refrigerant pressure sensor.
Is there any malfunction?
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Yes
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Replace the refrigerant pressure sensor.
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No
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Inspect the following:
• Refrigerant charging amount
• A/C compressor for seizure
Repair or replace the malfunctioning part according to the inspection result.
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6
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Access the climate control unit PID EVAP_TEMP using the M-MDS.
Monitor the climate control unit PID EVAP_TEMP while turning on and off the air conditioner by switching the control panel.
Is the EVAP_TEMP PID value normal?
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Yes
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Go to Step 9.
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No
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Go to Step 8.
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7
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Remove the climate control unit.
Reconnect the climate control unit connector.
Measure the voltage at the climate control unit terminal 1C (wiring harness-side).
Is the voltage normal?
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Yes
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Go to Step 11.
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No
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Go to the next step.
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8
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Inspect the evaporator temperature sensor.
Is there any malfunction?
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Yes
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Replace the evaporator temperature sensor.
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No
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Inspect for open or short circuit between evaporator temperature sensor and climate control unit.
Repair or replace the suspected wiring harness.
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9
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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?
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Yes
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Replace the instrument cluster (instrument cluster does not receive A/C request signal from climate control unit or transmit it to PCM).
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No
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Go to the next step.
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10
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Inspect the multi information display.
Is there any malfunction?
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Yes
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Replace the multi information display.
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No
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Replace the climate control unit (A/C switch malfunction or climate control unit does not determine A/C request or transmit the A/C request signal).
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11
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Remove the climate control unit.
Reconnect the climate control unit connector.
Start the engine and idle it.
Measure the voltage at the climate control unit terminal 2P (wiring harness-side) while turning on and off the air conditioner by switching the control panel.
Is the voltage change in specified according to air control panel switching?
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Yes
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Replace the instrument cluster (instrument cluster does not receive A/C request signal from climate control unit or transmit it to PCM).
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No
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Go to the next step.
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12
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Inspect for open or short circuit between climate control unit terminal 2P (wiring harness-side) and instrument cluster terminal 2I (wiring harness-side).
Is there any malfunction?
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Yes
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Repair or replace the suspected wiring harness.
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No
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Replace the climate control unit (A/C switch malfunction or climate control unit does not determine A/C request or transmit the A/C request signal).
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13
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Start the engine and idle it.
Turn the PCM PID ACCS to ON from OFF using the M-MDS simulation function.
Measure the voltage at the A/C magnetic clutch terminal A (wiring harness-side).
Is the voltage specified?
Specification:
• 10.5 V or more
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Yes
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Go to the next step.
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No
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Go to Step 15.
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14
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Inspect for continuity between A/C magnetic clutch terminal A (wiring harness-side) and body ground.
Is there continuity?
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Yes
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Inspect the magnetic clutch.
Replace the magnetic clutch if necessary.
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No
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Inspect the A/C compressor. (poor contact to ground)
• If there is any malfunction:
• If there is no malfunction:
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15
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Inspect the A/C relay.
(See RELAY INSPECTION.)
Is there any malfunction?
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Yes
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Replace the A/C relay.
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No
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Go to the next step.
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16
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Switch the ignition to off.
Remove the A/C relay.
Disconnect the PCM connector.
Inspect for continuity between A/C relay and PCM terminal 1I (wiring harness-side).
Is there continuity?
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Yes
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Inspect for open circuit between the following:
• Ignition switch (IG2) and A/C relay (vehicles without advanced keyless entry and push button start system)
• IG2 relay and A/C relay (vehicles with advanced keyless entry and push button start system)
• Battery positive terminal and A/C relay
• A/C relay and A/C magnetic clutch
Repair or replace the suspected wiring harness.
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No
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Repair or replace the suspected wiring harness.
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17
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Verify test results.
• If normal, return to the diagnostic index to service any additional symptoms.
• If a malfunction remains, inspect the related Service Information and perform the repair or diagnosis.
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