SAAB WIS ONLINE

B1745

Symptom: The SID unit shows -°C

B1745

No outside temperature

Fault symptoms

The SID unit shows -°C




Diagnostic procedure


1. Connect a Scan Tool, select the "SAAB INFO DISPLAY" menu followed by "READ VALUES" and "OUTDOOR TEMPERATURE".

2. If there is nothing wrong with the outside temperAture information, the temperature shown on the Scan Tool display should be the same as the outside temperature.

3. If the Scan Tool display shows -35°C (-25°F), there is an open circuit between pins 18 and 19. If the Scan Tool display shows +50°C (122°F), there is a short circuit between pins 18 and 19.

4. Unplug the outside temperature sensor and inspect the connector for poor contact and corrosion. Take a voltage reading across the connector pins. The correct reading should be 4.5-5 V. If the voltage reading is not OK, continue with point 7.


5. If the voltage reading is OK, measure the resistance directly across the sensor. Compare the resistance reading with the table.



Kohms (minimum)

Kohms (maximum)

± 0

5.8

6.2

+ 10 °C

3.8

4.1

+ 20 °C

2.5

2.8

+ 30 °C

1.7

1.9




6. If the resistance is not OK, change the sensor.

7. If the resistance is OK, plug the connector back into the sensor and clear the trouble code.

8. Check the wiring by connecting a BOB to the SID unit connector (SID unit disconnected).


9. Check for continuity/shorting between pins 18 and 2 of the connector and also between pins 19 and 1. Locate the short circuit or break in the wiring and take the necessary remedial action.