Air Conditioning System: Automatic Type 7B-51
DTC Detecting Condition and Trouble Area
DTC Troubleshooting
NOTE
When DTC B1502, B1513 and B1514 are indicated together, it is possible that “ORN” wire circuit open.
DTC Detecting Condition Trouble Area
Evaporator temperature sensor signal voltage is higher than or lower than
specified value for specified time continuously.
• Evaporator temperature sensor
circuit
• Evaporator temperature sensor
• HVAC control module
Step Action Yes No
1 Evaporator temperature sensor signal circuit check
1) Disconnect evaporator temperature sensor connector.
2) Check for proper connection to evaporator temperature
sensor at “WHT/BLK” and “ORN” 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?
Go to Step 5. Go to Step 2.
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 “G52-4” and “G52-3” terminals.
3) If OK, measure resistance between “WHT/BLK” wire
terminal of evaporator temperature sensor connector
and “G52-4” terminal of HVAC control module connector.
Is resistance below 5
Ω
?
Go to Step 3. “WHT/BLK” wire open
or high resistance
circuit.
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?
Go to Step 4. “WHT/BLK” wire
shorted to ground
circuit.
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?
Go to Step 5. “WHT/BLK” wire
shorted to other circuit.
5 Evaporator temperature sensor ground circuit check
1) Connect HVAC control module connector with ignition
switch turned OFF.
2) Measure resistance between “ORN” wire terminal of
evaporator temperature sensor connector and vehicle
body ground.
Is resistance below 5
Ω
?
Go to Step 7. Go to Step 6.
6 Evaporator temperature sensor ground circuit check
1) Measure resistance between “G52-3” terminal of HVAC
control module connector and vehicle body ground.
Is resistance below 5
Ω
?
“ORN” wire open or high
resistance circuit.
HVAC control module
faulty.
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