AC(diag)-18
Diagnostics for A/C System Malfunction
HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
B: BLOWER MOTOR DOES NOT ROTATE.
TROUBLE SYMPTOM:
•Blower motor does not rotate.
•Blower motor does not rotate in “HI”.
WIRING DIAGRAM:
AC-01336
B2B3B16
B419
B87
B86
MB-33 FUSE NO. 15
F/B NO. 22
SBF-3MAIN SBF
SBF-6
532
1235
21
B87B86
3412
B283B:
E
M
3
12
BLOWER MOTOR
AUTO A/C CONTROL MODULE
BATTERY
IGNITIONSWITCHBLOWER MOTORRELAY
POWERTRANSISTOR
B283
345678910
16 17 18 19 20
121112132425262122231415
B:B419
12345678121314151610119
AC(diag)-19
Diagnostics for A/C System Malfunction
HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
Step Check Yes No
1CHECK FUSE.
1) Remove the fuse No. 22 in fuse & relay box,
and the fuse No. 15 in main fuse box.
2) Check the condition of fuse.
Is any fuse blown out? Replace the fuse. Go to step 2.
2CHECK POWER SUPPLY FOR BLOWER
MOTOR.
1) Turn the ignition switch to ON.
2) Turn the blower switch to ON.
3) Measure the voltage between blower motor
and chassis ground.
Connector & terminal
(B87) No. 2 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 3.Repair the open
circuit of blower
motor power sup-
ply line harness.
3CHECK BLOWER MOTOR RELAY.
1) Turn the ignition switch to OFF.
2) Remove the blower motor relay.
3) Connect the battery positive (+) terminal to
terminal No. 2 of blower motor relay, and nega-
tive (–) terminal to terminal No. 3.
4) Measure the resistance between terminals
No. 1 and No. 5.
Te r m i n a l s
(B419) No. 1 — (B419) No. 5:
Is the resistance less than 1
Ω?
Go to step 4.Replace the
blower motor relay.
4CHECK BLOWER MOTOR.
1) Disconnect the connector from blower
motor.
2) Connect the battery positive (+) terminal to
terminal No. 2 of blower motor connector, and
negative (–) terminal to terminal No. 1.
3) Make sure the blower motor runs.
Does the blower motor run? Go to step 5.Replace the
blower motor.
Motor.>
5CHECK POOR CONTACT.
Check poor contact of auto A/C control module
connector.
Is there poor contact in con-
nector?
Repair the con-
nector.
Replace the auto
A/C control mod-
ule.
Control Unit (Auto
A/C Model).>
AC(diag)-20
Diagnostics for A/C System Malfunction
HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
C: COMPARTMENT TEMPERATURE DOES NOT CHANGE, OR A/C SYSTEM
DOES NOT RESPOND PROMPTLY.
WIRING DIAGRAM:
AC-01337
MAIN SBFSBF-6F/B NO.22
B360
F109
B143B:
F37A:
F35C:
1
9
F24
1
B361
F108
B136C:ECM
B283B:
B282A:
F27
B10
14
9
2830
2931
EE
C3C7
A4B13
43
12
C9
C33C24
A10B6
AUTO A/CCONTROLMODULE
MAGNETCLUTCH
MAIN FUSE BOX
THROUGH JOINTCONNECTORTHROUGH JOINTCONNECTOR
IGNITION SWITCHBATTERY
PRESSURESWITCH
A/C RELAY
B282B10 A:
B143
B360
F109
F108B:F37A:
F35F27C:
12345678910 11 12 13 14 15 16
1234 5678910 11 12 13 14 15 16 17 18 19 20
1234567891011122314
234 567891112 13 14 17 18 19 201101516
B361
1234567891011121314
123 8910411 12 13 14 15 165671718
12389104111213 1415165671236
7
45
131415
11
3031
1617891012
2627
18 192928222320 21
24 25
3412 8910 1112 13 14 15 16 17 18 19 20 21 22 23 24567
B136C:
1289563410 11 121920 2129 3031
13 14 15161727281822 2324 25 267
32 3334 35
B283
345678910
16 17 18 19 20
121112132425262122231415
B:
AC(diag)-21
Diagnostics for A/C System Malfunction
HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
Step Check Yes No
1CHECK FUSE.
1) Turn the ignition switch to OFF.
2) Remove the fuse No. 22 from fuse & relay
box.
3) Check the condition of fuse.
Is the fuse blown out? Replace the fuse. Go to step 2.
2CHECK SIGNAL TO A/C RELAY AND A/C
CONTROL MODULE.
1) Disconnect the A/C relay and auto A/C con-
trol module harness connector.
2) Turn the ignition switch to ON.
3) Measure the voltage between A/C relay
connector terminal and chassis ground.
4) Measure the voltage between auto A/C
control module harness connector terminal
and chassis ground.
Connector & terminal
(F27) No. 31 (+) — Chassis ground (–):
(B282) No. 10 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 5.Go to step 3.
3CHECK POWER SUPPLY FOR PRESSURE
SWITCH
1) Turn the ignition switch to OFF.
2) Disconnect the pressure switch harness
connector.
3) Turn the ignition switch to ON.
4) Measure the voltage between pressure
switch harness connector terminal and chassis
ground.
Connector & terminal
(B10) No. 2 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 4.Check for open or
short circuit in the
harness between
fuse and pressure
switch.
4CHECK HARNESS BETWEEN PRESSURE
SWITCH AND A/C RELAY, AUTO A/C CON-
TROL MODULE.
1) Turn the ignition switch to OFF.
2) Measure the resistance of harness
between pressure switch connector and A/C
relay connector.
3) Measure the resistance of harness
between pressure switch connector and auto
A/C control module connector.
Connector & terminal
(B10) No. 1 — (F27) No. 31:
(B10) No. 1 — (B282) No. 10:
Is the resistance less than 1
Ω?
Check the pres-
sure switch.
INSPECTION,
Pressure Switch
(Triple Pressure
Switch).>
Repair the har-
ness.
5CHECK POWER SUPPLY FOR A/C RELAY.
Measure the voltage between A/C relay con-
nector terminal and chassis ground.
Connector & terminal
(F27) No. 28 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 6.Check open or
short circuit of har-
ness between fuse
and A/C relay.
6CHECK A/C RELAY.
Check the A/C relay.
Is there a malfunction in the A/
C relay?
Replace the A/C
relay.
Go to step 7.
AC(diag)-22
Diagnostics for A/C System Malfunction
HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
7CHECK A/C ON SIGNAL.
1) Turn the ignition switch to OFF.
2) Connect the A/C relay and all disconnected
connectors.
3) Start the engine and turn the AUTO switch
to ON.
4) Turn the temperature control dial at maxi-
mum cool position.
5) Measure the voltage between auto A/C
control module harness connector terminal
and chassis ground.
Connector & terminal
(B283) No. 6 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 9.Go to step 8.
8CHECK HARNESS BETWEEN AUTO A/C
CONTROL MODULE AND ECM.
1) Turn the ignition switch to OFF.
2) Disconnect the harness connector of auto
A/C control module and ECM.
3) Measure the resistance of harness
between auto A/C control module connector
and ECM connector.
Connector & terminal
(B283) No. 6 — (B136) No. 24:
Is the resistance less than 1
Ω?
Replace the auto
A/C control mod-
ule.
Control Unit (Auto
A/C Model).>
Repair the har-
ness.
9CHECK MAGNET CLUTCH ON SIGNAL.
1) Stop the engine, and turn the AUTO switch
to OFF.
2) Turn the ignition switch to ON.
3) Measure the voltage between ECM con-
nector terminal and chassis ground.
Connector & terminal
(B136) No. 9 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 10.Check for open or
short circuit in the
harness between
A/C relay and
ECM.
10 CHECK MAGNET CLUTCH ON SIGNAL.
1) Start the engine and turn the AUTO switch
to ON.
2) Turn the temperature control dial at maxi-
mum cool position.
3) Measure the voltage between ECM con-
nector terminal and chassis ground.
Connector & terminal
(B136) No. 9 (+) — Chassis ground (–):
Is the voltage 0 V? Go to step 11.Replace the ECM.
REMOVAL,
Engine Control
Module (ECM).>
11 CHECK POWER SUPPLY FOR MAGNET
CLUTCH.
1) Stop the engine, and turn the AUTO switch
to OFF.
2) Disconnect the harness connector of mag-
net clutch.
3) Start the engine and turn the AUTO switch
to ON.
4) Turn the temperature control dial at maxi-
mum cool position.
5) Measure the voltage between magnet
clutch harness connector terminal and chassis
ground.
Connector & terminal
(F24) No. 1 (+) — Chassis ground (–):
Is the voltage more than 10 V? Go to step 12.Check for open or
short circuit in the
harness between
A/C relay and
magnet clutch.
Step Check Yes No
AC(diag)-24
Diagnostic Procedure for Actuators
HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
7. Diagnostic Procedure for Actuators
A: INTAKE DOOR ACTUATOR
TROUBLE SYMPTOM:
FRESH/RECIRC mode is not changed.
WIRING DIAGRAM:
AC-01338
B91
MAIN SBFSBF-6F/B NO.22
7
31
B283
B23B10
B:
B91
1234567
AUTO A/CCONTROL MODULE
INTAKE DOORACTUATOR
IGNITIONSWITCHBATTERY
B283B:
1234567891014151617181920212223111213242526
AC(diag)-25
Diagnostic Procedure for Actuators
HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
Step Check Yes No
1CHECK POWER SUPPLY FOR INTAKE
DOOR ACTUATOR.
1) Turn the ignition switch to OFF.
2) Disconnect the intake door actuator con-
nector.
3) Turn the ignition switch to ON.
4) Measure the voltage between intake door
actuator connector and chassis ground.
Connector & terminal
(B91) No. 7 (+) — Chassis ground (–):
Is the voltage 8 V (at normal
temperature)?
Go to step 2.Check for open or
short circuit in the
harness between
intake door actua-
tor and fuse.
2CHECK HARNESS BETWEEN AUTO A/C
CONTROL MODULE AND INTAKE DOOR
ACTUATOR.
1) Turn the ignition switch to OFF.
2) Disconnect the auto A/C control module
connector.
3) Measure the resistance between intake
door actuator connector and auto A/C control
module connector.
Connector & terminal
(B283) No. 10 — (B91) No. 1:
(B283) No. 23 — (B91) No. 3:
Is the resistance less than 1
Ω?
Go to step 3.Repair the har-
ness between auto
A/C control mod-
ule and intake
door actuator.
3CHECK OPERATION OF INTAKE DOOR AC-
TUATOR.
1) Connect the intake door actuator connec-
tor.
2) Ground the auto A/C control module con-
nector with a suitable wire.
3) Turn the ignition switch to ON, and check
the operation of intake door actuator.
Connector & terminal
(B283) No. 10 — Chassis ground:
Does the actuator move to the
FRESH side?
Go to step 4.Replace the intake
door actuator.
tor.>
4CHECK OPERATION OF INTAKE DOOR AC-
TUATOR.
1) Turn the ignition switch to OFF.
2) Ground the auto A/C control module con-
nector with a suitable wire.
3) Turn the ignition switch to ON, and check
the operation of intake door actuator.
Connector & terminal:
(B283) No. 23 — Chassis ground:
Does the actuator move to the
RECIRC side?
Replace the auto
A/C control mod-
ule.
Control Unit (Auto
A/C Model).>
Replace the intake
door actuator.
tor.>
AC(diag)-27
Diagnostic Procedure for Actuators
HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS)
Step Check Yes No
1CHECK POWER SUPPLY FOR MODE DOOR
ACTUATOR POSITION SENSOR.
1) Turn the ignition switch to OFF.
2) Disconnect the mode door actuator con-
nector.
3) Turn the ignition switch and AUTO switch to
ON.
4) Measure the voltage between auto A/C
control module connector terminals.
Connector & terminal
(B282) No. 8 (+) — (B282) No. 15 (–):
Is the voltage approx. 5 V? Go to step 2.Replace the auto
A/C control mod-
ule.
Control Unit (Auto
A/C Model).>
2CHECK POWER SUPPLY FOR MODE DOOR
ACTUATOR.
Measure the voltage between auto A/C control
module connector and chassis ground after
turning the air flow control switch to FACE posi-
tion.
Connector & terminal
(B283) No. 7 (+) — Chassis ground (–):
Is the voltage 8 V (at normal
temperature)?
Go to step 3.Replace the auto
A/C control mod-
ule.
Control Unit (Auto
A/C Model).>
3CHECK POWER SUPPLY FOR MODE DOOR
ACTUATOR.
Measure the voltage between auto A/C control
module connector and chassis ground after
turning the air flow control switch to DEF posi-
tion.
Connector & terminal
(B283) No. 20 (+) — Chassis ground (–):
Is the voltage 8 V (at normal
temperature)?
Go to step 4.Replace the auto
A/C control mod-
ule.
4CHECK HARNESS BETWEEN AUTO A/C
CONTROL MODULE AND MODE DOOR AC-
TUATOR.
1) Turn the A/C and ignition switch to OFF.
2) Disconnect the auto A/C control module
connector.
3) Measure the resistance between auto A/C
control module and mode door actuator con-
nector.
Connector & terminal
(B77) No. 1 — (B282) No. 15:
(B77) No. 3 — (B282) No. 8:
(B77) No. 5 — (B282) No. 3:
(B77) No. 6 — (B283) No. 20:
(B77) No. 7 — (B283) No. 7:
Is the resistance less than 1
Ω?
Go to step 5.Repair the har-
ness between auto
A/C control mod-
ule and mode door
actuator.
5CHECK MODE DOOR ACTUATOR POSI-
TION SWITCH SIGNAL.
1) Connect the connector of auto A/C control
module and mode door actuator.
2) Turn the ignition switch and AUTO switch to
ON.
3) Check the voltage between auto A/C con-
trol module connector terminals while chang-
ing the mode between DEF and FACE.
Connector & terminal
(B282) No. 3 (+) — (B282) No. 15 (–):
Does the voltage change
between 1 V (DEF) and 4 V
(FACE)?
Go to step 6.Replace the mode
door actuator.
tor.>
6CHECK POOR CONTACT.
Check poor contact of auto A/C control module
and connector.
Is there poor contact in con-
nector?
Repair the con-
nector.
Replace the auto
A/C control mod-
ule.
Control Unit (Auto
A/C Model).>