Inspection Of Hvac Control Module And Its Circuit - Suzuki Liana RH413 Service Manual

Inspection of HVAC Control Module and its Circuit

HVAC control module and its circuits can be checked at HVAC control module wiring coupler by measuring voltage.
CAUTION
!
HVAC control module can not be checked by itself. It is strictly prohibited to connect voltmeter to
HVAC control module with couplers disconnected from it.
Voltage Check
1) Remove HVAC control module referring to "HVAC Control Module Removal and Installation".
2) Check voltage at each terminal as shown below.
NOTE
As each terminal voltage is affected by the battery voltage, confirm that it is 11 V or more when ignition
switch is ON.
1
1. HVAC control module
Terminal Wire Color
G77-1 —
Electric load signal for
G77-2 BLU/BLK
blower motor
G77-3 PPL/WHT Rear defogger relay
G77-4 —
G77-5 BLU/YEL Blower motor controller
Blower motor control
G77-6 BLU/WHT
voltage feedback
14
30
2. HVAC control module connector "G77" (viewed from harness side)
Normal
Circuit
Voltage
— —
10.0 – 14.0V
about 2.0V
10.0 – 14.0 V Rear defogger switch OFF position
0 – 0.5 V
— —
about 0.0 V Ignition switch ON, Blower speed selector OFF
2.0 – 3.0V
10.0 – 14.0 V Ignition switch ON, Blower speed selector OFF
about 8.0 V
about 6.5 V
about 5.5 V
about 4.8 V
about 3.8 V
about 3.0 V
about 2.0 V
about 1.0 V
2
9 8
13 12 11 10
29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
Ignition switch ON, Blower speed selector OFF, 1st
or 2nd position.
Ignition switch ON, Blower speed selector between
3rd and HIGH position
Rear defogger switch ON position
Ignition switch ON, Blower speed selector between
LOW and HIGH position
Ignition switch ON, Blower speed selector 1st
position
Ignition switch ON, Blower speed selector 2nd
position
Ignition switch ON, Blower speed selector 3rd
position
Ignition switch ON, Blower speed selector 4th
position
Ignition switch ON, Blower speed selector 5th
position
Ignition switch ON, Blower speed selector 6th
position
Ignition switch ON, Blower speed selector 7th
position
Ignition switch ON, Blower speed selector HIGH
position
Heater and Ventilation:
S3RH0A7104014
7 6 5 4 3 2 1
I3RH0A710008-01
Condition
—
—
7A-11