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B1353

B1353

Cabin temperature sensor, open circuit/shorting to battery positive


Conditions

B1353: Control module input pin 33, open circuit or shorted to battery positive.

Diagnostic procedure

If diagnostic trouble code B1515 has been generated it should be dealt with first. See .


1. Connect the ISAT and obtain a "INDOOR TEMPERATURE SENSOR" readout. The readout shows volts and degrees Celsius and Fahrenheit. The voltage should be 1-4 V and the temperature should coincide with that of the ambient air.

2. Unplug the indoor temperature sensors's connector and check the voltage across connector pins 2 and 3. It should be about 4.5 - 5 V. The same reading can be obtained with the ISAT.



If the voltage is not OK, proceed to point 4.



3. Check the resistance directly across the cabin temperature sensor. It should vary with the temperature as shown in the table below.

Temperature

Minimum (kilo-ohms)

Maximum (kilo-ohms)

0 ° C

30.0

34.9

+ 10 ° C

18.5

21.1

+ 20 ° C

11.7

13.1

+25 ° C

9.5

10.5

+ 30 ° C

7.6

8.5

+ 40 ° C

4.9

5.7



Fit a new cabin temperature sensor if the resistance measurements are not OK. Clear the trouble codes and check that they are not generated afresh.




4. Unplug the ACC control module's connector. Connect a BOB to the wiring and check the leads for continuity and/or shorting as follows:


• across pin 15 of the ACC control module's connector and pin 2 of the sensor's connector

• take a reading across pin 33 of the ACC control module's connector and pin 3 of the sensor's connector

Rectify any faulty lead in the wiring.

5. Proceed to section .