2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 802

2010 Cadillac Truck Escalade EXT AWD V8-6.2L Page 802

- Evaporator Air Temperature Sensor Short to Ground

DTC B3933 05

- Evaporator Air Temperature Sensor Short to Battery or Open

Circuit Description

The HVAC control module supplies the evaporator 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 evaporator air temperature sensor signal circuit is less than -36掳C (-38掳F) or more than 215掳C (419掳F) for

more than 15 seconds.

Action Taken When the DTC Sets

The A/C compressor will be disabled.

Conditions for Clearing the DTC

* The DTC will become history if the HVAC control module no longer detects a failure.

* The history DTC will clear after 100 fault-free ignition cycles.

Reference Information

Schematic Reference

HVAC Schematics (See: Heating and Air Conditioning/Diagrams/Electrical Diagrams/HVAC - Manual)

Connector End View Reference

Component Connector End Views (See: Diagrams/Connector Views)

Description and Operation

* Air Delivery Description and Operation (See: Heating and Air Conditioning/Description and Operation/HVAC - Manual/Air Delivery

Description and Operation)

* Air Temperature Description and Operation (See: Heating and Air Conditioning/Description and Operation/HVAC - Manual/Air

Temperature Description and Operation)

Electrical Information Reference

* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Circuit

Testing/Circuit Testing)

* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic

Procedures/Connector Repairs/Connector Repairs)

* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/General

Electrical Diagnostic Procedures/Circuit Testing/Testing for Intermittent Conditions and Poor Connections)

* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/General Electrical Diagnostic Procedures/Wiring

Repairs/Wiring Repairs)

Scan Tool Reference

Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool A/C Evaporator Temperature Sensor parameter. The reading should be between -39掳F (-35掳C) and 208掳F (98掳C)

and change with evaporator air temperature changes.

Circuit/System Testing

Note: If the evaporator air temperature sensor has an out of range condition caused by a short to voltage, short to ground, or an open/high

resistance, the scan tool will display the same value: 11掳C (51掳F).

1. Ignition OFF, disconnect the harness connector at the evaporator air temperature sensor.

2. Ignition OFF, test for less than 10 ohms between the low reference circuit terminal 2 and ground.