CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER (MZ-CD 1.6 (Y6))]


B3E074061190W11

1. Turn the ignition switch to the ON position.

2. Connect the negative (-) lead of the tester to body ground.

3. By inserting the positive (+) lead of the tester into each climate control unit terminal, measure the voltage according to the terminal voltage table.

• If there is any malfunction, inspect the parts under "Inspection item (s)".
- If the parts under "Inspection item (s)" are found to be normal (except for terminal F), replace the climate control unit.
- For terminal F, first try replacing the power MOS FET. If there is still any malfunction, replace the climate control unit.

Terminal Voltage Table (Reference)

Terminal

Signal name

Connected to

Measurement condition

Voltage (V)

Inspection item (s)
A
TNS signal
PJB
Headlight switch OFF
1.0 or less
• Wiring harness: short circuit (Climate control unit-PJB: A-J-03 H)
• Panel light control switch
• Headlight switch
Headlight switch ON
B+
• Wiring harness: continuity, short circuit (Climate control unit-PJB: A-J-03 H)
• Panel light control switch
• Headlight switch
B
TNS signal
Panel light control switch
Headlight switch ON and panel light control switch at max. illumination
1.0 or less
• Wiring harness: continuity (Climate control unit-panel light control switch: B-F)
• Panel light control switch
• Climate control unit: terminal voltage (A)
Headlight switch ON and panel light control switch at min. illumination
12
• Wiring harness: short circuit (Climate control unit-panel light control switch: B-F)
C
Motor operation
Air mix actuator
Moving towards COLD
12
• Wiring harness: continuity, short circuit (Climate control unit-air mix actuator: C-D, E-F)
• Air mix actuator
Moving towards HOT
1.0 or less
D
Blower fan speed control
Power MOS FET
Fan stopped
1.0 or less
• Climate control unit: terminal voltage (F)
Fan: manual LO
2.9
Fan: manual HI
9.7
E
Motor operation
Air mix actuator
Moving towards COLD
1.0 or less
• Wiring harness: continuity, short circuit (Climate control unit-air mix actuator: E-F, C-D)
• Air mix actuator
Moving towards HOT
12
F
Blower motor feedback
• Blower motor
• Power MOS FET
Fan stopped
B+
1. Wiring harness: continuity, short circuit (Climate control unit-blower motor: F-B) (Climate control unit-power MOS FET: F-B, D-C) (Blower motor-blower relay: A-E) (Blower relay-fuse: A-HEATER 40 A, B-A/C 10 A)
2. Wiring harness: continuity (Power MOS FET-body ground: A-GND) (Blower relay-body ground: D-GND)
3. Power MOS FET
4. Blower motor
5. Blower relay
6. A/C 10 A fuse
7. HEATER 40 A fuse
8. Power MOS FET replacement
Fan: manual LO
9.8
Fan: manual HI
0.5
G
Motor operation
Airflow mode actuator
Switched to DEFROSTER
12
• Wiring harness: continuity, short circuit (Climate control unit-airflow mode actuator: G-F, I-D)
• Airflow mode actuator
Switched to VENT
1.0 or less
H
-
-
-
-
-
I
Motor operation
Airflow mode actuator
Switched to DEFROSTER
1.0 or less
• Wiring harness: continuity, short circuit (Climate control unit-airflow mode actuator: I-D, G-F)
• Airflow mode actuator
Switched to VENT
12
J
B+
ROOM 15 A fuse
Under any condition
B+
• Wiring harness: continuity, short circuit (Climate control unit- fuse: J-ROOM 15 A)
• ROOM 15 A fuse
K
IG2
A/C 10 A fuse
IG SW ON
B+
• Wiring harness: continuity, short circuit (Climate control unit- fuse: K-A/C 10 A)
• A/C 10 A fuse
IG SW LOCK
1.0 or less
• Wiring harness: continuity, short circuit (Climate control unit- fuse: K-A/C 10 A)
L
Potentiometer input
Airflow mode actuator
VENT
4.5
• Wiring harness: continuity, short circuit (Climate control unit-airflow mode actuator: L-C)
• Airflow mode actuator
• Climate control unit: terminal voltage (P)
BI-LEVEL
3.7
HEAT
2.9
HEAT/DEF
1.9
DEFROSTER
0.8
M
Motor operation
Air intake actuator
Switched to RECIRCULATE
1.0 or less
• Wiring harness: continuity, short circuit (Climate control unit-air intake actuator: M-G, O-E, Q-C)
• Air intake actuator
Switched to FRESH
12
N
Potentiometer input
Air mix actuator
Set temperature at MAX COLD
0.8
• Wiring harness: continuity, short circuit (Climate control unit-air mix actuator: N-C)
• Air mix actuator
• Climate control unit: terminal voltage (P)
Set temperature at MAX HOT
4.5
O
Motor operation
Air intake actuator
Switched to RECIRCULATE
12
• Wiring harness: continuity, short circuit (Climate control unit-air intake actuator: M-G, O-E)
• Air intake actuator
Switched to FRESH
1.0 or less
P
+5 V
• Air mix actuator
• Airflow mode actuator
• Solar radiation sensor
IG SW ON
5.2
• Wiring harness: short circuit (Climate control unit-air mix actuator, airflow mode actuator, solar radiation sensor: P-A, B, A)
• Air mix actuator
• Airflow mode actuator
• Solar radiation sensor
• Climate control unit: terminal voltage (K, V)
IG SW LOCK
0
• Climate control unit replacement
Q
Motor operation
Air intake actuator
Switched to RECIRCULATE
1.0 or less
• Wiring harness: continuity, short circuit (Climate control unit-air intake actuator: Q-C, M-G)
• Air intake actuator
Switched to FRESH
12
R
Cabin temperature sensor input
Cabin temperature sensor
Compared with temperature detected by cabin temperature sensor
Refer to graph 1
• Wiring harness: continuity (Climate control unit-cabin temperature sensor: R-D, U-B)
• Wiring harness: short circuit (Climate control unit-cabin temperature sensor: R-B)
• Cabin temperature sensor
• Climate control unit: terminal voltage (K, V)
S
Solar radiation sensor input
Solar radiation sensor
Incandescent light (approx. 60 W) shined directly on the solar radiation sensor from a distance of approx. 100 mm {3.9 in}
4.0
• Wiring harness: continuity (Climate control unit-solar radiation sensor: S-B, P-A)
• Climate control unit: terminal voltage (P)
• Solar radiation sensor
Blocking light to solar radiation sensor
1.0 or less
T
-
-
-
-
-
U
Sensor GND
• Cabin temperature sensor
• Air mix actuator
• Airflow mode actuator
Under any condition
1.0 or less
• Climate control unit: terminal voltage (V)
V
GND
Body ground
Under any condition
1.0 or less
• Wiring harness: continuity (Climate control unit-GND: V-GND)
W
Signal
-
-
-
-
X
Signal
-
-
-
-

-