NO.35 INEFFECTIVE OPERATION OF A/C DURING ENGINE STOP (i-stop system) [MZR 2.0 DISI i-stop]


id0103d3334000

35

INEFFECTIVE OPERATION OF A/C DURING ENGINE STOP (i-stop SYSTEM)

DESCRIPTION
•  A/C airflow temperature gradually increases or decreases while i-stop function is operating.
POSSIBLE CAUSE
A/C system malfunction
•  Climate control unit falsely recognizes MAX HOT or MAX COLD of air mix door on driver-side
―  Driver-side air mix actuator malfunction
―  Driver-side air mix actuator position sensor malfunction
―  Driver-side air mix door link stuck
•  Airflow temperature cannot be determined correctly.
―  Heater core temperature sensor (heater airflow temperature sensor) malfunction
•  Cabin temperature of target vehicle cannot be calculated.
―  Cabin temperature sensor malfunction
―  Solar radiation sensor malfunction
―  Ambient temperature sensor malfunction

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

1
Retrieve the PCM, instrument cluster and climate control unit (full-auto air conditioner) DTCs using the M-MDS.
Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
Go to the next step.
2
Does the malfunction occur only while the i-stop function is operating (engine stopped)?
Yes
Go to the next step.
No
Go to the applicable A/C malfunction diagnostic procedure.
3
Access the climate control unit PID CABIN TEMP using the M-MDS.
Does the CABIN TEMP PID value indicate the actual cabin temperature of the vehicle?
Yes
Go to Step 5.
No
Go to the next step.
4
Inspect the cabin temperature sensor.
Is there any malfunction?
Yes
Replace the cabin temperature sensor.
No
Repair or replace the wiring harness between cabin temperature sensor terminal D and climate control unit terminal 2M.
5
Access the climate control unit PID SOLAR_SSR_R using the M-MDS.
Does the SOLAR_SSR_R PID value indicate the actual cabin temperature of the vehicle?
Yes
Go to Step 7.
No
Go to the next step.
6
Inspect the solar radiation sensor.
Is there any malfunction?
Yes
Replace the solar radiation sensor.
No
Repair or replace the wiring harness between solar radiation sensor terminal B and climate control unit terminal 1F.
7
Measure the voltage at the climate control unit terminal 1G when the driver-side temperature setting is MAX HOT and MAX COLD.
Is the voltage normal?
Yes
Go to Step 9.
No
Go to the next step.
8
Inspect the driver-side air mix actuator.
Is there any malfunction?
Yes
Replace the driver-side air mix actuator.
No
Inspect the air mix actuator and linkage for sticking.
Repair or replace the malfunctioning part according to the inspection results.
9
Measure the voltage at the climate control unit terminal 1O while the engine is stopped via i-stop control.
Do the elapsed time and voltage values change?
Yes
Go to Step 11.
No
Go to the next step.
10
Inspect the heater core temperature sensor.
Is there any malfunction?
Yes
Replace the heater core temperature sensor.
No
Repair or replace the wiring harness between heater core temperature sensor terminal B and PCM terminal 1O.
11
Measure the voltage at the BCM terminal 1X.
Is the voltage normal?
Yes
The system is normal.
•  Effect is due to a possible change in the vehicle environment while the engine is stopped (change in solar radiation).
No
Go to the next step.
12
Inspect the ambient temperature sensor.
Is there any malfunction?
Yes
Replace the ambient temperature sensor.
No
Inspect the wiring harness between the following terminals:
•  Ambient temperature sensor terminal A—BCM 1X
•  Ambient temperature sensor terminal B—BCM 1H
Repair or replace the suspected wiring harness.
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].)