GM Service Manual Online
For 1990-2009 cars only

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.

DTC Descriptor

DTC B0161: Outside Air Temperature Sensor Circuit High

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Ambient Air Temperature Sensor Signal Circuit

B0160

B0161

B0161

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Circuit Description

The driver information center (DIC) applies 5 volts to the ambient air temperature sensor. The ambient air temperature sensor is a thermistor which varies in resistance as the temperature changes. As the resistance of the ambient air temperature sensor increases, the DIC senses a larger voltage drop across the sensor, indicating a lower temperature. As the resistance of the ambient air temperature sensor decreases, the DIC senses a smaller voltage drop across the sensor, indicating a higher temperature.

Conditions for Running the DTC

The DIC must be fully operational within a continuous voltage supply of 9-16 volts.

Conditions for Setting the DTC

The sensed temperature must be greater than -40°C (-40°F) for more than 2 seconds.

Action Taken When the DTC Sets

OC is displayed by the DIC in the compass/temperature mode when the condition is present.

Conditions for Clearing the DTC

    • DTC B0161 status changes from current to history when the condition is no longer present.
    • History DTC B0161 will clear after 100 consecutive fault-free ignition cycles.
    • The DTC can be cleared with a scan tool.

Reference Information

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Displays and Gages Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Scan Tool Data List

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the ambient air temperature sensor.
  2. Ignition OFF, test for less than 1.0 ohm of resistance between the low reference circuit and ground.
  3. If greater than 1.0 ohm, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the engine control module (ECM)/powertrain control module (PCM).
  4. Ignition ON, install a 3-amp fused jumper between the ambient air temperature sensor signal circuit and the low reference circuit. Verify SC is displayed on the DIC display.
  5. If SC is not displayed, test the ambient air temperature sensor signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the instrument panel cluster (IPC).
  6. If all circuits test normal, test or replace the 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 IPC replacement, setup, and programming