Suzuki Grand Vitara 2011 Manual page 1563

DTC Troubleshooting
NOTE
When DTC B1502, B1511, B1512 and B1530 are indicated together, it is possible that "BLK/RED" wire
circuit open.
Step
1 Evaporator temperature sensor signal circuit check
1) Disconnect evaporator temperature sensor connector
with ignition switch turned OFF.
2) Check for proper connection to evaporator temperature
sensor at "WHT/BLK" and "BLK/RED" wire terminals.
3) If OK, measure voltage between "WHT/BLK" wire
terminal of evaporator temperature sensor connector
and vehicle body ground with ignition switch turned ON.
Is voltage 4 – 6 V?
2 Evaporator temperature sensor signal circuit check
1) Disconnect connector from HVAC control module with
ignition switch turned OFF.
2) Check for proper connection to HVAC control module
connector at "G52-19" and "G52-13" terminals.
3) If OK, measure resistance between "WHT/BLK" wire
terminal of evaporator temperature sensor connector
and "G52-19" terminal of HVAC control module
connector.
Is resistance below 5
3 Evaporator temperature sensor signal circuit check
1) Measure resistance between "WHT/BLK" wire terminal
of evaporator temperature sensor connector and vehicle
body ground.
Is resistance infinity?
4 Evaporator temperature sensor signal circuit check
1) Measure voltage between "WHT/BLK" wire terminal of
evaporator temperature sensor connector and vehicle
body ground with ignition switch turned ON.
Is voltage 0 V?
5 Evaporator temperature sensor ground circuit check
1) Connect HVAC control module connector with ignition
switch turned OFF.
2) Measure resistance between "BLK/RED" wire terminal of
evaporator temperature sensor connector and vehicle
body ground.
Is resistance below 5
6 Evaporator temperature sensor ground circuit check
1) Measure resistance between "G52-13" terminal of HVAC
control module connector and vehicle body ground.
Is resistance below 5
7 Evaporator temperature sensor check
1) Check evaporator temperature sensor referring to "A/C
Evaporator Temperature Sensor Inspection".
Is it in good condition?
Action
Ω
?
Ω
?
Ω
?
Air Conditioning System:
Yes
Go to Step 5.
Go to Step 3.
Go to Step 4.
Go to Step 5.
Go to Step 7.
"BLK/RED" wire open or
high resistance circuit.
HVAC control module
faulty.
7B-38
No
Go to Step 2.
"WHT/BLK" wire open
or high resistance
circuit.
"WHT/BLK" wire
shorted to ground
circuit.
"WHT/BLK" wire
shorted to other circuit.
Go to Step 6.
HVAC control module
faulty.
Evaporator temperature
sensor faulty.