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Outside Air Temperature Display Malfunction

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

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Low Reference

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B0158 05

B0158 05

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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 driver information centre display.

Reference Information

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Driver Information Centre (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) and 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 Temperature Sensor.
  2. Ignition On, test for 4.8 - 5.2 V between the signal circuit terminal 1 and ground.
  3. 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.
    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.
  4. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the scan tool Ambient Air Temperature Sensor parameter displays 0%.
  5. If greater than the specified value, test the low reference circuit a short to voltage or an open/high resistance. If the circuit tests normal, replace the P16 instrument cluster.
  6. If all circuits test normal, test or replace the B9 Ambient Air Temperature Sensor.

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 .
  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.

Control Module References

   


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