B1502

DTC B1502: Inside Air Temperature Sensor Circuit Malfunction

Wiring Diagram










DTC Detecting Condition and Trouble Area






DTC Troubleshooting

NOTE:

When DTC B1503, B1504, B1511 and B1512 are indicated together, it is possible that sensor ground circuit is open.



1.
Was "Air Conditioning System Check" performed?
YES
Go to Step 2.
NO
Go to Air Conditioning System Check:Auto A/C.

2. Wire harness check

Turn ignition switch to OFF position.
Disconnect connectors from inside air temperature sensor and HVAC control module.
Check for proper connection to each signal circuit terminal and ground circuit terminal of inside air temperature sensor and HVAC control module connectors.
If OK, check that inside air temperature sensor circuit is as follows.
- Wiring harness resistance of each inside air temperature sensor signal circuit and ground circuit is less than 3 ohms
- Insulation resistance between inside air temperature sensor signal circuit and vehicle body ground is infinity
- Circuit voltage of each inside air temperature sensor signal circuit and ground circuit is 0 - 1 V with ignition switch turned ON

Are they in good condition?
YES
Go to Step 3.
NO
Inside air temperature sensor signal circuit and/or ground circuit are open, short or high resistance.

3. Inside air temperature sensor reference voltage check

Connect connector to HVAC control module with ignition switch turned OFF.
Turn ignition switch to ON position.
Measure voltage between signal terminal and ground terminal of inside air temperature sensor connector.

Is voltage 4.5 - 5.5 V?
YES
Go to Step 4.
NO
Substitute a known-good HVAC control module and recheck.

4. Inside air temperature sensor check

Check inside air temperature sensor for performance referring to Inspection Inside Air Temperature Sensor Inspection:Auto A/C.

Is it in good condition?
YES
Substitute a known-good HVAC control module and recheck.
NO
Replace inside air temperature sensor.