SAAB WIS ONLINE

Outside Air Temperature Display Inaccurate or Inoperative

Outside Air Temperature Display Inaccurate or Inoperative

Diagnostic Instructions


• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• Diagnostic Procedure Instructions provides an overview of each diagnostic category.


Diagnostic Fault Information

Circuit Short to Ground Open/High Resistance Short to Voltage Signal Performance
Ambient Air Temperature Sensor. Signal.

B0158 02

B0158 05

B0158 05

-

Low Reference

-

B0158 05

B0158 05

-



Circuit/System Description

The instrument cluster monitors the ambient air temperature sensor with a low reference circuit and 5 V signal circuit. The instrument cluster monitors the voltage drop across the sensor, which is proportional to temperature. When the ambient air temperatures are cold, the resistance of the sensor is high and the voltage signals are high. When the ambient air temperatures are hot, the resistance of the sensors is low and the voltage signals are low. The instrument cluster converts the voltage value to a temperature value of Celsius or Fahrenheit that will be displayed by the display.

Reference Information

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Driver Information Center (DIC) Description and Operation

Electrical Information Reference


• Circuit Testing

• Connector Repairs

• Testing for Intermittent Conditions and Poor Connections

• Wiring Repairs


Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool Ambient Air Temperature parameter. The reading should be between -40°C (-40°F) to +88°C (+190°F) and change with air temperature changes.

Circuit/System Testing


1. Ignition OFF, disconnect the harness connector at the B9 Ambient Air Sensor.

2. Ignition OFF, test for less than 5 Ω between the low reference circuit terminal 2 and ground.

3. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the P16 Instrument Cluster.

4. Ignition ON, test for 4.8-5.2 V between the signal circuit terminal 1 and ground.

5. If greater than the specified range, test the signal circuit terminal 1 for a short to voltage. If the circuit tests normal, replace the P16 Instrument Cluster.

6. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the P16 Instrument Cluster.

7. If all circuits test normal, test or replace the B9 Ambient Air Temperature Sensor and verify that the customer concern is not still present.

8. If the customer concern is still present, replace the P7 Display.


Component Testing


Static Test

1. Test the B9 Ambient Air Temperature Sensor by varying the sensor temperature while monitoring the sensor resistance.

2. Compare the readings with the Ambient Air Temperature Sensor Resistance and verify that the resistance is within the range of the specification.

3. If not within the specified range, replace the B9 Ambient Air Temperature Sensor.


Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.


• Ambient Air Temperature Sensor Replacement

• Control Module References for instrument cluster or display replacement, setup and programming