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 Descriptors

DTC B0158 03: Outside Air Temperature Sensor Circuit Voltage Below Threshold

DTC B0158 06: Outside Air Temperature Sensor Circuit Short to Ground or Open

DTC B0158 07: Outside Air Temperature Sensor Circuit Voltage Above Threshold

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Ambient Air Temperature Sensor Signal

B0158 06

B0158 06

B0158 07*

B0158 03, 07

Inside Air Temperature Sensor Signal

B0163 06

B0163 06

B0163 07*

B0163 03, 07

Left Sunload Sensor Signal

B0183

B0183

B0183*

--

Right Sunload Sensor Signal

B0188

B0188

B0188*

--

Evaporator Temperature Sensor Signal

B3933 06

B3933 06

B3933 06*

--

Low Reference

--

B3933 06, B0158 06, B0163 06

B3933 06, B0158 07, B0163 07

B0158 07, B0163 07

Sunload sensors Ground Circuit

--

B0183, B0188

B0183, B0188

--

* If a signal circuit is shorted to voltage B0158, B0163, B0183, B0188 and B3933 will all set.

Circuit/System Description

The HVAC control module supplies the ambient air temperature sensor with a low reference circuit and 5-volt signal circuit. The HVAC control module determines the voltage drop across the sensor, which is proportional to temperature. As the air temperature increases, the sensor resistance decreases and the voltage signal decreases. As the air temperature decreases, the sensor resistance increases and the voltage signal increases.

Conditions for Running the DTC

The ignition is turned ON.

Conditions for Setting the DTC

The HVAC control module detects the ambient air temperature sensor signal circuit is less than -36°C (-38°F) or more than 215°C (419°F) for more than 15 seconds.

Action Taken When the DTC Sets

    • The HVAC control module will display dashes for outside air temperature.
    • The DIC will display SERVICE A/C SYSTEM.
    • The system operates using a default value.

Conditions for Clearing the DTC

    • The DTC will become history if the HVAC control module no longer detects the condition that set the DTC.
    • The history DTC will clear after 50 fault-free ignition cycles.

Reference Information

Schematic Reference

HVAC Schematics

Connector End View Reference

HVAC Connector End Views

Description and Operation

Air Temperature Description and Operation

Electrical Information Reference

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

Scan Tool Reference

    •  Scan Tool Output Controls
    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the outside air temp sensor.
  2. Ignition OFF, test for less than 1 ohm of resistance between the low reference circuit B 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 HVAC control module.
  4. Ignition ON, test for 5 volts between the low reference circuit terminal B and the 5-volt reference signal circuit terminal A.
  5. If not the specified voltage, test the signal circuit for a short to voltage, short to ground or open/high resistance. If the circuit tests normal, replace the HVAC control module.
  6. If all circuits test normal, test or replace the outside air temperature sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Ambient Air Temperature Sensor Replacement
    •  Control Module References for HVAC control module replacement, setup and programming