Suzuki Engine 2002 GRAND VITARA SQ420 Service Manual page 285

6-1-144 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H25 ENGINE)
Table B-4 A/C Signal Circuit Check (If Equipped)
CIRCUIT DIAGRAM
+B
3
13
14
12 v
A/C+
9
10
11
12
+BB
8 7
6
23 22
21 20
35 34
33
[A] : Terminal arrangement of ECM (PCM) coupler
viewed from harness side
[B] : Vehicle without immobilizer control system
[C] : Vehicle with immobilizer control system
1. ECM (PCM)
2. Combination meter (ECT meter)
3. HVAC control module
CIRCUIT DESCRIPTION
HVAC control module outputs A/C ON signal to ECM (PCM) when A/C switch and heater blower motor are
turned ON.
Then compressor and condenser fan are turned ON by ECM (PCM) when engine conditions are normal.
INSPECTION
Step
1 A/C Switch Signal Circuit check :
1) Remove ECM (PCM) cover.
2) Check voltage between E61-28 and ground
under following conditions.
A/C switch signal specification
Ignition switch ON and A/C switch and/or
heater blower switch OFF : 10 – 14 V
Ignition switch ON and both A/C switch and
heater blower switch ON : 0 – 1.5 V
Are check results as specified?
2
[B] C51-3-19
YEL/WHT
[C] C51-1-17
PNK/WHT
GRN/BLK
8
E61-25
PPL/RED
6 5
5 4 3 2 1 4
17 16
19 18 17 16 15 14 13 12 11 10 9 15
26 25
32 31 30 29 28 27 26 25 24
4. A/C condenser fan motor relay
5. A/C condenser fan motor
6. A/C compressor
7. A/C compressor relay
8. Refrigerant pressure switch
9. Heater blower motor relay
Action
1
E61-5
E61-21
E61-13
E61-28
C51-2-3
E61-35
C51-2-2
C51-3-25
C51-2-8
12V C51-3-26
C51-2-9
[A]
C51-3 C51-1
4 3
3 2 1
13 12
14 13 12 11 10 9 8 7
11 10 9 8
20 19
24 23 22 21 20 19 18 18 17 16
10. Heater blower motor
11. Heater blower motor controller
12. DLC
13. "HTR 60A" fuse
14. "HTR 40 A" fuse
15. "HTR 15 A" fuse
Yes
A/C signal circuit is good
condition.
4
YEL/BLU
M RED/BLU
BLK
5
7
PNK
WHT/RED
6
15
IG2
IG1 17
BLK/WHT
WHT
18
BLK/ORN
BLK/GRN
BLK/GRN
BLK/BLU
BLK/BLU
C51-2
2 1 2
7 6 5 4 3
6 5
9
7 19 18 17 16 15 14 13 12 11 10
15 14 21 20
28 27 26 25 24 23 22
Faulty "GRN/BLK" wire,
evaporative temperature
is bellow 2.5°C, 36.5°F or
faulty A/C system.
A/C+
YEL/GRN
RED/BLK
+B
16
1
8
16. "A/C" 25 A fuse
17. Ignition switch
18. Battery
No