NO.23 A/C DOES NOT WORK SUFFICIENTLY [L3 Turbo]SM2444523
NO.23 A/C DOES NOT WORK SUFFICIENTLY [L3 Turbo]

id0103b4802900

23

A/C DOES NOT WORK SUFFICIENTLY
DESCRIPTION
• A/C compressor magnetic clutch does not engage when A/C is turned on.
POSSIBLE CAUSE
• Improper refrigerant charging amount
• Open A/C magnetic clutch
• Open circuit between the A/C relay and the A/C magnetic clutch
• Poor ground of A/C magnetic clutch
• Refrigerant pressure sensor is stuck open
• Evaporator temperature sensor malfunction
• A/C relay is stuck open
• Seized A/C compressor
• Open circuit between the A/C switch and the PCM through both the refrigerant pressure sensor and the A/C amplifier

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
Turn the ignition switch to the ON position (engine off).
Retrieve the PCM, BCM and climate control unit DTCs.
(See ON-BOARD DIAGNOSTIC TEST [L3 Turbo].)
(See DTC INSPECTION [BCM].)
(See DTC DISPLAY [FULL-AUTO AIR CONDITIONER].)
Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [L3 Turbo].)
(See DTC TABLE [BCM].)
(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 [L3 Turbo].)
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?
Yes
Full-auto air conditioner:
• Go to Step 6.
Manual air conditioner:
• Go to the next step.
No
Go to Step 15.
3
Access the BCM PID ACSW using the M-MDS.
(See PID/DATA MONITOR INSPECTION [BCM].)
Monitor the ACSW PID while turning on and off the air conditioner by switching the control panel.
Is the PID normal?
(See PID/DATA MONITOR TABLE [BCM].)
Yes
Go to Step 6.
No
Go to the next step.
4
Remove the climate control unit.
(See CLIMATE CONTROL UNIT REMOVAL [MANUAL AIR CONDITIONER].)
Reconnect the climate control unit connector.
Start the engine and idle it.
Measure the voltage at the climate control unit terminal J (wiring harness-side) while turning on and off the air conditioner by control panel.
Is the voltage change in specified according to the control panel switching?
(See CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER].)
Yes
Go to the next step.
No
Go to Step 6.
5
Inspect for open or short circuit between climate control unit terminal J (wiring harness-side) and BCM terminal 3L (wiring harness-side).
Is there any open or short circuit detected?
Yes
Repair or replace the suspected wiring harness.
No
Replace the BCM (BCM can not receive the A/C request signal from climate control unit or transmit it to PCM).
(See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION.)
6
Start the engine and idle it.
Measure the voltage at the following terminals (wiring harness-side):
• Full-auto air conditioner:
― Climate control unit terminal 1F
• Manual air conditioner:
― Climate control unit terminal I
Is the voltage normal?
(See CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER].)
(See CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER].)
Yes
Go to Step 9.
No
Go to the next step.
7
Turn the ignition switch to the ON position (engine off).
Measure the voltage at the following terminals (wiring harness-side):
• Full-auto air conditioner:
― Climate control unit terminal 1C
• Manual air conditioner:
― Climate control unit terminal K
Is the voltage normal?
(See CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER].)
(See CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER].)
Yes
Go to the next step.
No
Replace the climate control unit.
(See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
(See CLIMATE CONTROL UNIT REMOVAL [MANUAL AIR CONDITIONER].)
(See CLIMATE CONTROL UNIT INSTALLATION [MANUAL AIR CONDITIONER].)
8
Inspect for open or short circuit between the following terminals (wiring harness-side):
• Full-auto air conditioner:
― Climate control unit terminal 1C and evaporator temperature sensor terminal A
― Climate control unit terminal 1F and evaporator temperature sensor terminal B
• Manual air conditioner:
― Climate control unit terminal K and evaporator temperature sensor terminal A
― Climate control unit terminal I and evaporator temperature sensor terminal B
Is there any open or short circuit detected?
Yes
Repair or replace the suspected wiring harness.
No
Replace the evaporator temperature sensor.
(See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
(See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].)
9
Inspect the refrigerant pressure sensor.
(See REFRIGERANT PRESSURE SENSOR INSPECTION [FULL-AUTO AIR CONDITIONER].)
(See REFRIGERANT PRESSURE SENSOR INSPECTION [MANUAL AIR CONDITIONER].)
Is the refrigerant pressure sensor normal?
Yes
Full-auto air conditioner:
• Go to Step 13.
Manual air conditioner:
• Replace the climate control unit (A/C switch malfunction or climate control unit can not determine A/C request or transmit it to BCM). (See CLIMATE CONTROL UNIT REMOVAL [MANUAL AIR CONDITIONER].) (See CLIMATE CONTROL UNIT INSTALLATION [MANUAL AIR CONDITIONER].)
No
Go to the next step.
10
Inspect the refrigerant pressure.
(See REFRIGERANT PRESSURE CHECK.)
Is the refrigerant pressure normal?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
11
Turn the ignition switch to the ON position (engine off).
Measure the voltage at the following terminals (wiring harness-side):
• Full-auto air conditioner:
― Climate control unit terminal 1N
• Manual air conditioner:
― Climate control unit terminal N
Is the voltage normal?
(See CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER].)
(See CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER].)
Yes
Go to the next step.
No
Replace the climate control unit.
(See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
(See CLIMATE CONTROL UNIT REMOVAL [MANUAL AIR CONDITIONER].)
(See CLIMATE CONTROL UNIT INSTALLATION [MANUAL AIR CONDITIONER].)
12
Inspect for open or short circuit between the following terminals (wiring harness-side):
• Full-auto air conditioner:
― Climate control unit terminal 1J and refrigerant pressure sensor terminal A
― Climate control unit terminal 1N and refrigerant pressure sensor terminal B
― Climate control unit terminal 1C and refrigerant pressure sensor terminal C
• Manual air conditioner:
― Climate control unit terminal E and refrigerant pressure sensor terminal A
― Climate control unit terminal N and refrigerant pressure sensor terminal B
― Climate control unit terminal K and refrigerant pressure sensor terminal C
Is there any open or short circuit detected?
Yes
Repair or replace the suspected wiring harness.
No
Replace the refrigerant pressure sensor.
(See REFRIGERANT PRESSURE SENSOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
(See REFRIGERANT PRESSURE SENSOR REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].)
13
Verify the multi information display indication of A/C system while turning on and off the air conditioner by switching the control penal.
Does the multi information display indicate properly?
Yes
Replace the BCM (BCM can not receive the A/C request signal from climate control unit or transmit it to PCM).
(See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION.)
No
Go to the next step.
14
Inspect the multi information display.
(See MULTI INFORMATION DISPLAY INPUT/OUTPUT CHECK MODE.)
Is the multi information display normal?
Yes
Replace the climate control unit (A/C switch malfunction or climate control unit can not determine A/C request or transmit it to BCM).
(See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)
No
Repair or replace the malfunctioning part according to the inspection results.
15
Start the engine and idle it.
Verify that the A/C relay operation sound is heard while PCM PID ACCS to ON from OFF using the M-MDS simulation function.
Is the A/C operation sound heard?
Yes
Go to the next step.
No
Go to Step 17.
16
Inspect the A/C compressor magnetic clutch.
(See MAGNETIC CLUTCH INSPECTION [FULL-AUTO AIR CONDITIONER].)
(See MAGNETIC CLUTCH INSPECTION [MANUAL AIR CONDITIONER].)
Is the magnetic clutch normal?
Yes
Inspect and repair for open or short circuit between battery positive terminal and A/C compressor terminal A.
No
Replace the magnetic clutch.
(See MAGNETIC CLUTCH DISASSEMBLY/ASSEMBLY [FULL-AUTO AIR CONDITIONER].)
(See MAGNETIC CLUTCH DISASSEMBLY/ASSEMBLY [MANUAL AIR CONDITIONER].)
17
Inspect the A/C relay.
(See RELAY INSPECTION [L3 Turbo].)
Is the A/C relay normal?
Yes
Go to the next step.
No
Replace the A/C relay.
18
Remove the A/C relay.
Start the engine and idle it.
Measure the voltage at the A/C relay terminal 2 (fuse box side connector) while PCM PID ACCS to ON from OFF using the M-MDS simulation function.
Is the voltage below 1.0 V?
Yes
Inspect and repair for open circuit between ignition switch terminal B and A/C relay terminal 1.
No
Inspect and repair for open or short to power supply circuit between PCM terminal 1I and A/C relay terminal 2.
19
Verify test results.
• If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [L3 Turbo].)
• If the 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, reprogram the PCM if a later calibration is available. Retest.