HVAC System - Automatic Chevrolet Captiva I рестайлинг

Fastener Tightening Specifications

Fastener Tightening Specifications

Sensor Resistance Table

Sensor Resistance Table

Scheme 37

Scheme 38

Scheme 39

Scheme 40

Diagnostic Code Index

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit/System Description

The HVAC control module monitors the ambient air temperature sensor to display ambient air temperature. The temperature sensor is a 2-wire negative temperature co-efficient thermistor. The HVAC control module applies 5 volts to an internal input resistor that is connected to the signal circuits of the ambient air temperature sensor. The HVAC control module provides the ground to the ambient air temperature sensor through the low reference circuit. The HVAC control module monitors the voltage drop across the ambient air temperature sensor and uses the input for automatic control calculations. 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 HVAC control module converts the voltage value to a temperature value of Celsius and Fahrenheit that will be displayed by the driver information center (DIC).

Conditions for Running the DTC

Ignition ON.

Conditions for Setting the DTC

1. The HVAC control module detects the sensor signal circuit is less than 0.05 volts.
2. The HVAC control module detects the sensor signal circuit is greater than 4.9 volts.

Action Taken When the DTC Sets

1. The default value of 85°C (185°F) will be substituted for the ambient air temperature sensor data by the HVAC control module.
2. The DIC will display - -.

Conditions for Clearing the DTC

1. The DTC will become history if the HVAC control module no longer detects a failure.
2. The history DTC will clear after 100 fault-free ignition cycles.

Reference Information

Schematic Reference

HVAC Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

1. «Air Temperature Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-temperature-description-and-operation)
2. «Air Delivery Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-delivery-description-and-operation)

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, observe the scan tool Outside Air Temp. Raw parameter. The reading should be between -35 and +85°C (-39 and +185°F) and change with air temperature changes.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the ambient air temperature sensor.
2. Ignition OFF, test for less than 10 ohms between the following low reference circuit terminal B and ground. 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.
3. Ignition ON, verify the scan tool Outside Air Temp. Raw parameter is less than -35°C (-39°F). If greater than the specified range, test the following signal circuit terminal A for a short to ground. If the circuit tests normal, replace the HVAC control module.
4. Install a 3A fused jumper wire between the following signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool Outside Air Temp. Raw parameter is greater than 85°C (185°F). If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
5. If all circuits test normal, test or replace the ambient air temperature sensor.

Component Testing

1. A thermometer can be used to test the sensor off the vehicle in warn and or cold water. «Sensor Resistance Table»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__sensor-resistance-table) for this test.
2. Test the ambient air temperature sensor by varying the sensor temperature while monitoring the sensor resistance.
3. Compare the readings with the Temperature VS Resistance table and verify that the resistance is within 5 percent of the specification. If not within the specified range, replace the sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Ambient Air Temperature Sensor Replacement»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
2. «Control Module References»(/chevrolet/captiva/i-2011-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for HVAC control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Inside Air Temperature Sensor

The HVAC control module supplies the inside 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. The inside air temperature sensor refers to the passenger compartment.

Upper and Lower Air Duct Temperature Sensors

The HVAC control module supplies the air duct temperature sensors 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.

Ignition ON.

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

The system operates using a default value.

1. The DTC will become history if the HVAC control module no longer detects the condition that set the DTC.
2. The history DTC will clear after 100 fault-free ignition cycles.

Schematic Reference

HVAC Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

1. «Air Temperature Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-temperature-description-and-operation)
2. «Air Delivery Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-delivery-description-and-operation)

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool Inside Air Temp. Sensor or the appropriate Duct Actual parameter. The reading should be between -35 and +98°C (-39 and +208°F) and change with inside passenger compartment or upper/lower air duct air temperature changes.

1. Ignition OFF, disconnect the harness connector at the appropriate temperature sensor.
2. Ignition OFF, test for less than 10 ohms between the appropriate low reference circuit terminal listed below and ground: Inside air temperature sensor terminal D Upper/lower air temperature sensor terminal 2 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.
3. Ignition ON, verify that both the scan tool Inside Air Temp. Sensor or the appropriate Duct Actual parameter is less than -35°C (-39°F). If greater than the specified range, test the appropriate signal circuit terminal listed below for a short to ground. If the circuit tests normal, replace the HVAC control module. Inside air temperature sensor terminal A Upper/lower air temperature sensor terminal 1
4. Install a 3A fused jumper wire between the appropriate circuits listed below. Verify the scan tool Inside Air Temp. Sensor or the appropriate Duct Actual parameter is greater than 98°C (208°F). Inside air temperature sensor signal circuit terminal A and low reference circuit terminal D Upper/lower air temperature sensor signal circuit terminal 1 and low reference circuit terminal 2 If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
5. If all circuits test normal, test or replace the appropriate air temperature sensor.

1. A thermometer can be used to test the sensor off the vehicle in warn and or cold water. «Sensor Resistance Table»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__sensor-resistance-table) for this test.
2. Test the ambient air temperature sensor by varying the sensor temperature while monitoring the sensor resistance.
3. Compare the readings with the Temperature VS Resistance table and verify that the resistance is within 5 percent of the specification. If not within the specified range, replace the sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Inside Air Temperature Sensor Replacement»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic)
2. «Duct Air Temperature Sensor Replacement - Upper»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic)
3. «Duct Air Temperature Sensor Replacement - Lower»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic)
4. «Control Module References»(/chevrolet/captiva/i-2011-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for HVAC control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Circuit Description

The sunload sensor is a 2-wire photo diode. The vehicle uses left and right sunload sensors. The two sensors are integrated into the sunload sensor assembly along with the ambient light sensor. Body ground and signal circuits enable the sensor to operate. As the sunload increases, the sensor signal decreases. The sensor operates within an intensity range between completely dark and very bright. The sensor signal varies between 0 and 5 volts. The HVAC control module converts the signal to a range between 0 and 255 counts. The sunload sensor provides the HVAC control module with a measurement of the amount of light shining on the vehicle. Bright or high intensity light causes the vehicles interior temperature to increase. The HVAC system compensates for the increased temperature by diverting additional cool air into the vehicle.

The following DTCs are for the left and right sunload sensors.

1. B0183 is for the left sunload sensor.
2. B0188 is for the right sunload sensor.

Ignition ON.

The HVAC control module detects the signal circuit is less than 5 counts or more than 250 counts.

If the DTC is set the system will act as if no sunload condition exists.

1. The DTC will become history if the HVAC control module no longer detects the condition that set the DTC.
2. The history DTC will clear after 100 fault-free ignition cycles.

Schematic Reference

HVAC Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

1. «Air Temperature Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-temperature-description-and-operation)
2. «Air Delivery Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-delivery-description-and-operation)

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the appropriate scan tool Sunload Sensor parameter. The reading should be between 5 and 250 counts and change with sunlight changes.

1. Ignition OFF, disconnect the harness connector at the sunload sensor.
2. Test for less than 10 ohms between the ground circuit terminal C and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, test for 4.8-5.2 volts between the appropriate signal circuit terminal listed below and ground: Left solar load sensor circuit terminal A Right solar load sensor circuit terminal B If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the HVAC control module. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HVAC control module.
4. If all circuits test normal, test or replace the sunload sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Headlamp Automatic Control Ambient Light Sensor Replacement»(/chevrolet/captiva/i-2011-2013/remont/exterior-lights/#lighting-system)
2. «Control Module References»(/chevrolet/captiva/i-2011-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for HVAC control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The actuators operate using 5 circuits. A 5 V reference, low reference, signal circuit and two bi-directional 0 or 12 volt control circuits. The HVAC control module supplies a low reference and 5 V reference to the potentiometer. The HVAC control module monitors the voltage drop across the potentiometer on the door position signal circuit. As the actuator door changes position the door position signal circuit voltage also changes. The two bi-directional control circuits enable the actuator to operate. Both circuits are set to 0 volts when the HVAC control module detects, from the feedback potentiometer, that the actuator is in the desired position. In order to move the actuator, the HVAC control module switches the appropriate control circuit to 12 volts.

1. DTC B0228 is for the recirculate actuator.
2. DTC B0423 is for the air temperature actuator.
3. DTC B3779 is for the mode actuator.

1. Ignition ON.
2. The HVAC module is ON.

The actual door position differs from the commanded door position by more than 4 counts or the HVAC control module detects the door position signal circuit is less than 5 counts or greater than 250 counts.

The control circuit is deactivated for the appropriate actuator.

1. The DTC becomes history when the HVAC control module no longer detects the condition that set the DTC.
2. The history DTC will clear after 100 fault-free ignition cycles.

Schematic Reference

1. «Air Delivery Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-delivery-description-and-operation)
2. «Air Temperature Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-temperature-description-and-operation)
3. «HVAC Schematics»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic)

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

1. «Air Delivery Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-delivery-description-and-operation)
2. «Air Temperature Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-temperature-description-and-operation)

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, command the appropriate actuator in both directions with a scan tool. The scan tool Door Position parameter reading should be between 5 and 250 counts.

1. Ignition OFF, disconnect the harness connector at the appropriate actuator.
2. Ignition OFF, test for less than 10 ohms between the low reference circuit terminal 1 and ground. 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.
3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground. If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HVAC control module. If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the HVAC control module.
4. Verify the appropriate scan tool Door Position parameter is greater than 250 counts. If less than the specified range, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the HVAC control module.
5. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1. Verify the appropriate scan tool Door Position parameter is less than 3 counts. If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
6. Ignition OFF, test for less than 10 ohms between the control circuit terminal 4 and ground. If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the HVAC control module.
7. Ignition OFF, test for less than 10 ohms between the control circuit terminal 5 and ground. If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the HVAC control module.
8. Connect a test lamp between control circuit terminal 5 and control circuit terminal 4.
9. Command the appropriate actuator door in both directions with a scan tool. The test lamp should turn ON and OFF when commanded in both directions. If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the HVAC control module.
10. If both circuits test normal, test or replace the actuator.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Air Inlet Valve Actuator Replacement»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic)
2. «Mode Valve Actuator Replacement»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic)
3. «Temperature Valve Actuator Replacement»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic)
4. «Control Module References»(/chevrolet/captiva/i-2011-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for HVAC control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The HVAC control module supplies the evaporator 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. When the refrigerant temperature is low the sensor resistance and voltage signal are high.

Ignition ON.

The HVAC control module detects the evaporator temperature sensor signal circuit is less than 0.05 volts or greater than 4.9 volts.

1. The air conditioning (A/C) compressor will be disabled.
2. The default valve of -20°C (-4°F) will be substituted for the evaporator temperature sensor data by the HVAC control module.

1. The DTC will become history if the HVAC control module no longer detects a failure.
2. The history DTC will clear after 100 fault-free ignition cycles.

Schematic Reference

HVAC Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

1. «Air Temperature Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-temperature-description-and-operation)
2. «Air Delivery Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-delivery-description-and-operation)

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition OFF, disconnect the harness connector at the evaporator temperature sensor.
2. Ignition OFF, test for less than 1 ohm between the low reference circuit terminal B and ground. If greater than the specified range, test the low reference circuit terminal for an open/high resistance. If the circuit tests normal, replace the HVAC control module.
3. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal A and ground: If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the HVAC control module. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HVAC control module.
4. If all circuits test normal, test or replace the evaporator temperature sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Air Conditioning (A/C) Refrigerant Low Temperature Sensor Replacement (Before February 20th 2012)»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning (A/C) Refrigerant Low Temperature Sensor Replacement (After February 20th 2012)»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
2. «Control Module References»(/chevrolet/captiva/i-2011-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for HVAC control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The engine control module (ECM) monitors the high side refrigerant pressure through the A/C refrigerant pressure sensor. The ECM supplies a 5-volt reference and a low reference to the sensor. Changes in the A/C refrigerant pressure cause the A/C refrigerant pressure sensor signal to the ECM to vary. When the pressure is low, the signal voltage is low. When the pressure is high, the ECM commands the cooling fans on. When pressure is too high or too low, the ECM will not allow the A/C compressor clutch to engage.

1. The engine is running.
2. The battery voltage is between 11-18 volts.

1. The ECM detects that the A/C pressure is less than 1 psi (0.01 volt).
2. The ECM detects that the A/C pressure is greater than 425 psi (4.90 volts).

1. The ECM will not illuminate the malfunction indicator lamp (MIL).
2. The ECM stores the failure records.
3. The A/C compressor clutch is disabled.
4. A/C indicator on HVAC control module is disabled.

1. The history DTC will clear after 40 consecutive ignition cycles have occurred without a malfunction.
2. The DTC will become history if the ECM no longer detects a failure.

Diagnostic Aids

A malfunction within the refrigerant system causing high pressure can cause this DTC to set.

Schematic Reference

HVAC Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

1. «Air Temperature Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-temperature-description-and-operation)
2. «Air Delivery Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-delivery-description-and-operation)

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, observe the scan tool A/C High Side Pressure parameter in the ECM. The reading should be between 0.1-4.90 volts (1-425 psi), and change with pressure.

1. Ignition OFF, disconnect the harness connector at the A/C refrigerant pressure sensor.
2. Ignition OFF, test for less than 10 ohms between the low reference circuit terminal 1 and ground. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 2 and ground. If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.
4. Verify the scan tool A/C High Side Pressure Sensor parameter is less than 0.1 volts (1 psi). If greater than the specified range, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the ECM.
5. Install a 3A fused jumper wire between the signal circuit terminal 3 and the 5-volt reference circuit terminal 2. Verify the scan tool A/C High Side Pressure Sensor parameter is greater than 4.90 volts (425 psi). If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
6. If all circuits test normal, test or replace the A/C refrigerant pressure sensor.

Perform Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
2. «Control Module References»(/chevrolet/captiva/i-2011-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the A/C switch is pressed, the HVAC control assembly sends a serial data message to the engine control module (ECM) for an A/C request. This input will request the ECM to ground the A/C compressor clutch relay control circuit, which will switch the A/C CLTCH relay. With the relay contacts closed, battery voltage is supplied to the A/C compressor clutch assembly.

1. The ignition voltage is between 9 and 18 volts.
2. The engine speed is more than 600 RPM.
3. An A/C request is made.

1. A short to ground on the A/C compressor clutch relay control circuit.
2. A short to voltage on the A/C compressor clutch relay control circuit.
3. An open circuit on the A/C compressor clutch relay control circuit or relay.
4. An internally shorted or excessively low resistance A/C clutch relay coil.

1. The A/C clutch relay is commanded OFF.
2. The conditions for which the DTC was set will be stored in the Failure Records data only. No information will be stored as Freeze Frame data.

The history DTC will clear after 40 fault-free ignition cycles.

Schematic Reference

HVAC Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

1. «Air Delivery Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-delivery-description-and-operation)
2. «Air Temperature Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-temperature-description-and-operation)

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Engine running, command the A/C compressor On and OFF using a scan tool. The A/C compressor clutch should engage and disengage as commanded.

1. Ignition OFF, disconnect the X1 harness connector at X50A fuse block-underhood.
2. Remove the control circuit terminal 46 using the correct terminal release tool, connect the X1 harness connector to the X50A fuse block-underhood.
3. Connect a test lamp between the control circuit terminal 46 and B+, engine running.
4. Verify the test lamp turns ON and OFF when commanding the Q2 A/C compressor clutch ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Ignition OFF Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 ECM. If the test lamp is always ON Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K20 Engine Control Module. If the test lamp turns ON and OFF
5. Ignition OFF and all vehicle systems OFF, connect the harness connector at the X50A fuse block-underhood, disconnect the harness connector at the Q2 A/C compressor clutch. It may take up to 2 minutes for all vehicle systems to power down.
6. Test for less than 10 ohms between the Q2 A/C compressor clutch ground terminal A and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
7. Connect a test lamp between the control circuit terminal B and ground.
8. Verify the test lamp turns ON and OFF when commanding the Q2 A/C compressor clutch ON and OFF with a scan tool. If the test lamp is always OFF and the circuit fuse is good Ignition OFF, disconnect the X1 harness connector at the X50A fuse block-underhood. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the X50A fuse block-underhood. If the test lamp is always OFF and the circuit fuse is open Ignition OFF Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the Q2 A/C compressor clutch. If the test lamp is always ON Ignition OFF, disconnect the X1 harness connector at the X50A fuse block-underhood, Ignition ON. Test for less then 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the X50A fuse block-underhood. If the test lamp turns ON and OFF
9. Replace the Q2 A/C compressor clutch.

1. Ignition OFF, disconnect the A/C COMP relay.
2. Test for 60-180 ohms between terminals 85 and 86. If the resistance is not within the specified range, replace the relay.
3. Test for infinite resistance between the following terminals: 30 and 86 30 and 87 30 and 85 85 and 87 If not the specified value, replace the relay.
4. Install a 30-amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87. If greater than the specified range, replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Air Conditioning Compressor Replacement (L4)»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (V6)»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
2. «Relay Replacement (Within an Electrical Center)»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions__relay-replacement-within-an-electrical-center) , «Relay Replacement (Attached to Wire Harness)»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-repair-instructions)
3. «Control Module References»(/chevrolet/captiva/i-2011-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for HVAC control module and ECM replacement, setup, and programming

Symptoms - HVAC Systems - Automatic

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the HVAC System. Refer to «Checking Aftermarket Accessories»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__checking-aftermarket-accessories) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
3. Verify the A/C compressor clutch turns freely and is not seized.
4. The A/C compressor will not operate in cold outside air temperatures. Refer to «Air Temperature Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-temperature-description-and-operation) .
5. The following could cause window fogging: Wet carpet or mats High humidity Interior water leak Blocked A/C evaporator drain tube Maximum passenger capacity Blocked body pressure relief valves
6. Inspect the air distribution system for causes of reduced air flow: Obstructed or dirty passenger compartment air filter, if equipped Blocked or damaged air inlet or outlet vents

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «Air Conditioning Compressor Malfunction»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic)
2. «Blower Motor Malfunction»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic)
3. «Air Temperature Malfunction»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic)
4. «Leak Testing»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
5. «Noise Diagnosis - HVAC Module»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__noise-diagnosis-hvac-module)
6. «Noise Diagnosis - Blower Motor»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__noise-diagnosis-blower-motor)
7. «Odor Diagnosis»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__odor-diagnosis)

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When the A/C switch is pressed, the HVAC control assembly sends a serial data message to the engine control module (ECM) for an A/C request. This input will request the ECM to ground the A/C compressor clutch relay control circuit, which will switch the A/C CLTCH relay. With the relay contacts closed, battery voltage is supplied to the A/C compressor clutch assembly.

The following conditions must be met in order for the ECM to turn on the compressor clutch

1. Battery voltage is between 9-16 volts.
2. Engine coolant temperature (ECT) is less than 123°C (253°F).
3. Engine speed is less than 4760 RPM.
4. Engine speed is more than 600 RPM.
5. A/C high side pressure is between 2929-269 kPa (425-39 psi).
6. Throttle position is less than 100 percent.
7. Evaporator temperature is greater than 0°C (32°F).
8. ECM does not detect excessive torque load.
9. ECM does not detect insufficient idle quality.

Schematic Reference

HVAC Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

1. «Air Temperature Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-temperature-description-and-operation)
2. «Air Delivery Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-delivery-description-and-operation)

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Engine running, command the A/C compressor On and OFF using a scan tool. The A/C compressor clutch should engage and disengage as commanded.

1. Ignition OFF, disconnect the X1 harness connector at X50A fuse block-underhood.
2. Remove the control circuit terminal 46 using the correct terminal release tool, connect the X1 harness connector to the X50A fuse block-underhood.
3. Connect a test lamp between the control circuit terminal 46 and B+, engine running.
4. Verify the test lamp turns ON and OFF when commanding the Q2 A/C compressor clutch ON and OFF with a scan tool. If the test lamp is always OFF Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON. Test for less than 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V Ignition OFF Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the K20 ECM. If the test lamp is always ON Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the K20 Engine Control Module. If the test lamp turns ON and OFF
5. Ignition OFF and all vehicle systems OFF, connect the harness connector at the X50A fuse block-underhood, disconnect the harness connector at the Q2 A/C compressor clutch. It may take up to 2 minutes for all vehicle systems to power down.
6. Test for less than 10 ohms between the Q2 A/C compressor clutch ground terminal A and ground. If 10 ohms or greater Ignition OFF. Test for less than 2 ohms in the ground circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, repair the open/high resistance in the ground connection. If less than 10 ohms
7. Connect a test lamp between the control circuit terminal B and ground.
8. Verify the test lamp turns ON and OFF when commanding the Q2 A/C compressor clutch ON and OFF with a scan tool. If the test lamp is always OFF and the circuit fuse is good Ignition OFF, disconnect the X1 harness connector at the X50A fuse block-underhood. Test for less than 2 ohms in the control circuit end to end. If 2 ohms or greater, repair the open/high resistance in the circuit. If less than 2 ohms, replace the X50A fuse block-underhood. If the test lamp is always OFF and the circuit fuse is open Ignition OFF Test for infinite resistance between the control circuit and ground. If less than infinite resistance, repair the short to ground on the circuit. If infinite resistance, replace the Q2 A/C compressor clutch. If the test lamp is always ON Ignition OFF, disconnect the X1 harness connector at the X50A fuse block-underhood, Ignition ON. Test for less then 1 V between the control circuit and ground. If 1 V or greater, repair the short to voltage on the circuit. If less than 1 V, replace the X50A fuse block-underhood. If the test lamp turns ON and OFF
9. Replace the Q2 A/C compressor clutch.

1. Ignition OFF, disconnect the A/C COMP relay.
2. Test for 60-180 ohms between terminals 85 and 86. If the resistance is not within the specified range, replace the relay.
3. Test for infinite resistance between the following terminals: 30 and 86 30 and 87 30 and 85 85 and 87 If not the specified value, replace the relay.
4. Install a 30-amp fused jumper wire between relay terminal 85 and 12 volts. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87. If greater than the specified range, replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Air Conditioning Clutch Assembly Replacement»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__air-conditioning-clutch-assembly-replacement)
2. «Air Conditioning Compressor Replacement (L4)»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) , «Air Conditioning Compressor Replacement (V6)»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
3. «Control Module References»(/chevrolet/captiva/i-2011-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for BCM, ECM, and HVAC control module replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The blower motor control module is an interface between the HVAC control module and the blower motor. The blower motor speed control, battery positive and ground circuits enable the control module to operate. The HVAC control module provides a variable voltage to the blower motor control module to request the selected blower speed. The blower motor control module provides a pulse width modulation (PWM) signal to the blower motor in order to control the blower motor speed. The module supplies 12 volts to the blower motor through the blower motor voltage supply circuit.

Be sure the blower motor housing is not shorted to a grounded surface causing the blower motor to always be on in high speed.

Schematic Reference

HVAC Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

1. «Air Temperature Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-temperature-description-and-operation)
2. «Air Delivery Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-delivery-description-and-operation)

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, command the blower motor ON and OFF with a scan tool. Monitor/feel the operation of the blower motor.

1. Ignition OFF, disconnect the X2 harness connector at the blower motor control module.
2. Test for less than 1.0 ohm between the ground circuit terminal 5 and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 6 and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse (HVAC BLWR 40-amp) in the underhood fuse block is open, test all components connected to the B+ circuit and replace as necessary.
4. Connect a DMM between the control circuit terminal 3 and ground.
5. Cycle the blower motor from OFF to HIGH. The voltage should increase while changing between the commanded states. If voltage remains greater than 11.5 volts while changing between the commanded states, test the control circuit for a short to voltage. If the circuit test normal, replace the HVAC control module. If voltage remains less than 1.0 volts while changing between the commanded states, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HVAC control module. If voltage is between 1.0-11.5 volts and does not increase when changing between the commanded states, replace the HVAC control module.
6. Ignition OFF, reconnect the X2 harness connector at the blower motor control module. Disconnect the harness connector at the blower motor.
7. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal A and ground. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the blower motor control module.
8. Connect a test lamp between the control circuit terminal B and the B+ circuit terminal A.
9. Turn the blower motor on high speed then to low speed. The test lamp intensity should be bright when in high speed and very dim or off when the blower is on low speed. If the test lamp intensity does not vary, test the control circuit for a short to voltage, short to ground, or an open/high resistance. If the circuit tests normal, replace the blower motor control module.
10. If all circuits test normal, test or replace the blower motor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Blower Motor Control Module Replacement»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
2. «Blower Motor Replacement»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
3. «Control Module References»(/chevrolet/captiva/i-2011-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for HVAC replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/captiva/i-2011-2013/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Air Temperature Sensors

The air temperature sensors are a 2-wire negative temperature co-efficient thermistor. The vehicle uses the following air temperature sensors

1. Ambient air temperature sensor
2. Inside air temperature sensor assembly
3. Upper air temperature sensor
4. Lower air temperature sensor
5. A/C evaporator temperature sensor

A signal and low reference circuit enables the sensor to operate. As the air temperature surrounding the sensor increases, the sensor resistance decreases. The sensor signal voltage decreases as the resistance decreases. The sensor operates within a temperature range between -40 to +101°C (-40 to +215°F). The sensor signal varies between 0-5 volts. The input of the duct air temperature sensors are different from the ambient and inside air temperature sensors. The HVAC control module converts the signal to a range between 0-255 counts. As the air temperature increases the count value will decrease.

Sun Load Sensor Assembly

The sunload sensor is a 2-wire photo diode. The vehicle uses left and right sunload sensors. The 2 sensors are integrated into the sunload sensor assembly. Low reference and signal circuits enable the sensor to operate. As the light shining upon the sensor gets brighter, the sensor resistance increases. The sensor signal decreases as the resistance increases. The sensor operates within an intensity range between completely dark and bright. The sensor signal varies between 0-5 volts. The HVAC control module converts the signal to a range between 0-255 counts. The sunload sensor provides the HVAC control module a measurement of the amount of light shining on the vehicle. Bright, or high intensity, light causes the vehicles inside temperature to increase. The HVAC system compensates for the increased temperature by diverting additional cool air into the vehicle. If the HVAC control module detects a malfunctioning sensor, then the control module software will use a defaulted sunload value.

Heater Core Coolant Pump

The primary purpose of the heater core coolant pump is to circulate engine coolant through the HVAC heater core when heat is required in the cabin for comfort. This normally happens when the vehicle is in an Auto Stop and the mechanical pump is not spinning. If the HVAC control module has determined heat is needed for the cabin, this pump is turned on once the engine is shut off so the customer does not notice a change in heater duct discharge temperatures. The SGCM starter generator control module controls the auxiliary coolant pump. Heater core coolant pump relay supplies voltage to the heater core coolant pump.

Schematic Reference

HVAC Schematics

Connector End View Reference

COMPONENT CONNECTOR END VIEWS - INDEX

Description and Operation

1. «Air Delivery Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-delivery-description-and-operation)
2. «Air Temperature Description and Operation»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__air-temperature-description-and-operation)

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/chevrolet/captiva/i-2011-2013/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, cover the sunload sensor assembly with a shop towel or other suitable item. Verify the scan tool Right Sunload Sensor and Left Sunload Sensor parameters are within 3 counts of each other. If not within the specified range, refer to Sun Load Sensor Circuit Malfunction.
2. Measure actual outside air temperature using a thermometer. Compare this value to the scan tool Outside Air Temp. Raw parameter. The measured temperature should be within 5 degrees of parameter. If not within the specified range, refer to Ambient Air Temperature Sensor Circuit Malfunction.
3. Measure actual inside air temperature using a thermometer. Compare this value to the scan tool Inside Air Temp. Sensor parameter. The measured temperature should be within 5 degrees of parameter. If not within the specified range, refer to Inside Air Temperature Sensor Circuit Malfunction.
4. Measure actual temperature using a thermometer at each of the duct temperature sensors. Compare this value to the appropriate scan tool Duct Actual parameter. The measured temperature should be within 5 degrees of appropriate Duct Actual parameter. If not within the specified range, refer to Duct Temperature Sensor Circuit Malfunction.
5. Ignition ON, command the heater core pump ON and OFF with a scan tool. Observe the operation of heater core pump. If the heater core coolant pump does not turn on and off with each command , refer to Heater Core Coolant Pump Malfunction.

Sun Load Sensor Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the sunload sensor.
2. Test for less than 10 ohms between the ground circuit terminal C and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, test for 4.8-5.2 volts between the ground circuit terminal C and the appropriate signal circuit terminal listed below: Left solar load sensor circuit terminal A Right solar load sensor circuit terminal B If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the HVAC control module. If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HVAC control module.
4. If all circuits test normal, test or replace the sunload sensor.

Ambient Air Temperature Sensor Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the ambient air temperature sensor.
2. Ignition OFF, test for less than 10 ohms between the following low reference circuit terminal B and ground. 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.
3. Ignition ON, verify the scan tool Outside Air Temp. Raw parameter is less than -35°C (-39°F). If greater than the specified range, test the following signal circuit terminal A for a short to ground. If the circuit tests normal, replace the HVAC control module.
4. Install a 3A fused jumper wire between the following signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool Outside Air Temp. Raw parameter is greater than 85°C (185°F). If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
5. If all circuits test normal, test or replace the ambient air temperature sensor.

Inside Air Temperature Sensor Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the inside air temperature sensor.
2. Test for less than 1 ohm between the ground circuit terminal C and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify a test lamp illuminates between the control circuit terminal B and ground. If the test lamp does not illuminate, test the ground circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
4. Ignition OFF, test for less than 10 ohms between the low reference circuit terminal D and ground: 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.
5. Ignition ON, verify that the scan tool Inside Air Temp. Sensor parameter is less than -35°C (-39°F). If greater than the specified range, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the HVAC control module.
6. Install a 3A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal D. Verify the scan tool Inside Air Temp. Sensor is greater than 98°C (208°F). If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
7. If all circuits test normal, test or replace the inside air temperature sensor.

Duct Temperature Sensor Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the appropriate duct temperature sensor.
2. Ignition OFF, test for less than 10 ohms between the low reference circuit terminal 2 listed below and ground: 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.
3. Ignition ON, verify that the appropriate scan tool Duct Actual parameter is less than -35°C (-39°F). If greater than the specified range, test the signal circuit terminal 1 for a short to ground. If the circuit tests normal, replace the HVAC control module.
4. Install a 3A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 2. Verify the appropriate scan tool Duct Actual parameter is greater than 98°C (208°F). If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
5. If all circuits test normal, test or replace the appropriate duct temperature sensor.

1. A thermometer can be used to test the sensor off the vehicle in warn and or cold water. «Sensor Resistance Table»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic__sensor-resistance-table) for this test.
2. Test the appropriate temperature sensor by varying the sensor temperature in water while monitoring the sensor resistance.
3. Compare the readings with the Temperature VS Resistance table and verify that the resistance is within 5 percent of the specification. If not within the specified range, replace the sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Duct Air Temperature Sensor Replacement - Upper»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic)
2. «Duct Air Temperature Sensor Replacement - Lower»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic)
3. «Inside Air Temperature Sensor Replacement»(/chevrolet/captiva/i-2011-2013/remont/automatic-hvac-system/#hvac-system-automatic)
4. «Headlamp Automatic Control Ambient Light Sensor Replacement»(/chevrolet/captiva/i-2011-2013/remont/exterior-lights/#lighting-system)
5. «Control Module References»(/chevrolet/captiva/i-2011-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for HVAC replacement, setup, and programming

Ambient Air Temperature Display Updating

The HVAC control module will not request compressor clutch engagement when the ambient air temperature display is less than 2°C (35°F). In order to inspect compressor clutch operation during cold weather conditions, the vehicle must be brought inside and the ambient air temperature display must be updated. To update the ambient air temperature display on the HVAC control module, perform the following procedure

With out Scan Tool

1. Turn ON the ignition.
2. Simultaneously press the A/C and RECIRC switches.

With Scan Tool

1. Turn ON the ignition.
2. Use the Instant OAT Update procedure in the scan tool Special Functions.

Calibration Procedure

Use the following steps to perform the calibration update

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Select HVAC Control Module.
4. Select Special Functions.
5. Select recalibrate All Motors.
6. Select ON, wait 60 seconds.

Scheme 41

Heater and Air Conditioning Control Replacement

Scheme 42

Air Inlet Valve Actuator Replacement

Removal Procedure

1. Remove the driver knee bolster. Refer to «Driver Knee Bolster Replacement»(/chevrolet/captiva/i-2011-2013/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
2. Remove the communication interface module, if equipped. Refer to «Communication Interface Module Replacement»(/chevrolet/captiva/i-2011-2013/remont/entertainment-systems/#cellular-system-entertainment-system-and-navigation-system) .
3. Disconnect the electrical connector from the mode actuator.
4. Remove the mode actuator screws from the evaporator case assembly.
5. Remove the mode actuator from the evaporator case assembly.

Installation Procedure

1. Install the mode actuator to the evaporator case assembly.
2. Install the mode actuator screws to the evaporator case assembly and tighten to 1.5 N.m (13 lb in).
3. Connect the electrical connector to the mode actuator.
4. Install the communication interface module, if equipped. Refer to «Communication Interface Module Replacement»(/chevrolet/captiva/i-2011-2013/remont/entertainment-systems/#cellular-system-entertainment-system-and-navigation-system) .
5. Install the driver knee bolster. Refer to «Driver Knee Bolster Replacement»(/chevrolet/captiva/i-2011-2013/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
6. Calibrate the actuators. Refer to «Actuator Recalibration»(/chevrolet/captiva/i-2011-2013/remont/manual-hvac-system/#hvac-system-manual) .
7. Cycle the ignition and verify proper operation.

1. Remove the driver knee bolster. Refer to «Driver Knee Bolster Replacement»(/chevrolet/captiva/i-2011-2013/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
2. Remove the communication interface module, if equipped. Refer to «Communication Interface Module Replacement»(/chevrolet/captiva/i-2011-2013/remont/entertainment-systems/#cellular-system-entertainment-system-and-navigation-system) .
3. Disconnect the electrical connector from the mode actuator.
4. Remove the mode actuator screws from the evaporator case assembly.
5. Remove the mode actuator from the evaporator case assembly.
6. Remove the screws retaining the mode cam bracket (1) to the evaporator case assembly.
7. Remove the mode cam bracket (1) from the evaporator case assembly.
8. Remove the mode cam (2) and the mode cam levers (3) from the evaporator case assembly.

1. Install the mode cam levers (3) to the evaporator case assembly.
2. Align and install the mode cam (2) to the mode cam levers (3). Rotate the mode cam (2) to verify mode door operation.
3. Install the mode cam bracket (1) to the evaporator case assembly.
4. Install the mode cam bracket screws to the evaporator case assembly and tighten the screws to 1.5 N.m (13 lb in).
5. Install the mode actuator to the evaporator case assembly.
6. Install the mode actuator screws to the evaporator case assembly and tighten the screws to 1.5 N.m (13 lb in).
7. Connect the electrical connector to the mode actuator.
8. Install the communication interface module, if equipped. Refer to «Communication Interface Module Replacement»(/chevrolet/captiva/i-2011-2013/remont/entertainment-systems/#cellular-system-entertainment-system-and-navigation-system) .
9. Install the driver knee bolster. Refer to «Driver Knee Bolster Replacement»(/chevrolet/captiva/i-2011-2013/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
10. Calibrate the actuators. Refer to «Actuator Recalibration»(/chevrolet/captiva/i-2011-2013/remont/manual-hvac-system/#hvac-system-manual) .
11. Cycle the ignition and verify proper operation.

1. Remove the instrument panel compartment. Refer to «Instrument Panel Compartment Replacement»(/chevrolet/captiva/i-2011-2013/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
2. Disconnect the electrical connector from the air temperature actuator.
3. Remove the air temperature actuator screws from the HVAC module.
4. Remove the air temperature actuator from the HVAC module.

1. Align the air temperature actuator with the door shaft and rotate into position.
2. Install the air temperature actuator screws to the HVAC module. Tighten Tighten the screws to 1.5 N.m (13 lb in).
3. Connect the electrical connector to the air temperature actuator.
4. Calibrate the actuators. Refer to «Actuator Recalibration»(/chevrolet/captiva/i-2011-2013/remont/manual-hvac-system/#hvac-system-manual) .
5. Cycle the ignition and verify proper operation.
6. Install the instrument panel compartment. Refer to «Instrument Panel Compartment Replacement»(/chevrolet/captiva/i-2011-2013/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .

Scheme 43

Air Conditioning Refrigerant Temperature Sensor Replacement

Scheme 44

Duct Air Temperature Sensor Replacement - Upper

Scheme 45

Duct Air Temperature Sensor Replacement - Lower

Scheme 46

Inside Air Temperature Sensor Replacement

Air Delivery Description and Operation

The air delivery description and operation is divided into 4 areas

1. HVAC control components
2. Air speed
3. Air delivery
4. Recirculation operation

HVAC Control Components

HVAC Control Module

The HVAC control module is a non-class 2 device that interfaces between the operator and the HVAC system to maintain air temperature and distribution settings. The battery positive and ignition 1 voltage circuits provide power to the control module. The control module supports the following features

Mode Actuator

The mode actuator is a 5-wire bi-directional electric motor that incorporates a feedback potentiometer. Low reference, 5-volt reference, position signal, and 2 control circuits enable the actuator to operate. The control circuit uses either a 0 or 12-volt value to coordinate the actuator movement. When the actuator is at rest, both control circuits have a value of 0 volt. In order to move the actuator, the HVAC control module grounds one of the control circuits while providing the other with 12 volts. The HVAC control module reverses the polarity of the control circuits to move the actuator in the opposite direction. When the actuator shaft rotates, the potentiometer's adjustable contact changes the door position signal between 0-5 volts.

The auxiliary HVAC control module uses a range of 0-255 counts to index the actuator position. The door position signal voltage is converted to a 0-255 count range. When the module sets a commanded, or targeted, value, one of the control circuits is grounded. As the actuator shaft rotates the changing position signal is sent to the module. Once the position signal and the commanded value are the same, the module grounds both control circuits.

Blower Motor Control Processor

The blower motor control processor is an interface between the HVAC control module and the blower motor. The blower motor speed control, battery positive voltage and ground circuits enable the control processor to operate. The HVAC control module provides a pulse width modulation (PWM) signal to the control processor in order to command the blower motor speed. The processor supplies 12 volts to the blower motor through the blower motor voltage supply circuit. The control processor uses the blower motor ground or low reference as a low side control to adjust the blower motor speed.

Air Speed

The blower motor forces air to circulate within the vehicles interior. The vehicle operator determines the blower motors speed by placing the blower motor switch in a desired speed position. The blower motor will only operate if the blower motor switch is in any position other than OFF, and the ignition switch is in the RUN position.

Once a blower speed is selected, the blower speed remains constant until a new speed is selected.

As the requested blower speed increases, the following conditions occur

1. The HVAC control module increases the amount of time that the blower motor speed control circuit is modulated to ground.
2. The voltage and duty cycle, measured between the blower motor speed control circuit and ground, decrease.

As the requested blower speed decreases, the following conditions occur

1. The HVAC control module decreases the amount of time that the blower motor speed control circuit is modulated to ground.
2. The voltage and duty cycle, measured between the blower motor speed control circuit and ground, increase.

Afterblow

Afterblow is a feature that dries the evaporator core by operating the blower motor after the engine is turned off. This reduces the microbial growth that can create undesireable odors. The vehicle does not come with the afterblow feature enabled. If the afterblow feature is required due to an odor concern, it must be turned on by the scan tool. Certain items need to have happened for afterblow to operate

1. The A/C compressor operated on the latest key cycle.
2. The system voltage is at least 11 volts to start and 10 volts to continue to run.
3. The ignition has been in the OFF position for at least 30 minutes.

Once the above conditions have been met the following events will occur

1. The blower will run for roughly 2 minutes.
2. The recirculation door moves to the outside air position.
3. The mode valve moves to the floor position.

Air Delivery

The mode actuator controls air delivery. The HVAC control module controls the actuator in order to distribute airflow to a desired outlet. When the vehicle operator selects the defrost, mix-blend or floor positions, the A/C compressor clutch engages and the recirculation actuator will be moved to the outside air position. The flow of air during the various modes of operation is as follows

1. Panel-Outside Air and Recirculation inlet air setting, full air from Instrument Panel (I/P) outlets
2. Bi-Level-I/P and front and rear floor outlets
3. Floor-Small amount of air to the right and left side window outlets and a larger amount of air to the Front and Rear floor outlets
4. Mix-Blend-Floor and defroster outlets with a slight bleed to the I/P outlets
5. Defrost-Defrost outlets with a small amount of air to the right and left side window outlets and to the Driver Side floor outlet and a very small amount to the Rear floor outlet

Recirculation Operation

The recirculation actuator is a 5-wire bi-directional electric motor that incorporates a feedback potentiometer. Low reference, 5-volt reference, position signal, and 2 control circuits enable the actuators to operate. The control circuits use either a 0 or 12-volt value to coordinate the actuator movement. When the actuator is at rest, both control circuits have a value of 0 volt. In order to move the actuator, the HVAC control module grounds one of the control circuits while providing the other with 12 volts. The HVAC control module reverses the polarity of the control circuits to move the actuator in the opposite direction. When the actuator shaft rotates, the potentiometer's adjustable contact changes the door position signal between 0-5 volts.

Air Temperature Description and Operation

The air temperature controls are divided into 4 areas

1. HVAC control components
2. Heating and A/C operation
3. Engine coolant
4. A/C cycle

HVAC Control Module

The HVAC control module is a serial data device that interfaces between the operator and the HVAC system to maintain air temperature and distribution settings. The battery positive and ignition 1 voltage circuits provide power to the control module. The control module supports the following features

Air Temperature Actuator

The air temperature actuator is a 5-wire bi-directional electric motor that incorporate a feedback potentiometer. Low reference, 5-volt reference, position signal, and 2 control circuits enable the actuator to operate. The control circuits use either a 0 or 12-volt value to coordinate the actuator movement. When the actuator is at rest, both control circuits have a value of 0 volts. In order to move the actuator, the HVAC control module grounds one of the control circuits while providing the other with 12 volts. The HVAC control module reverses the polarity of the control circuits to move the actuator in the opposite direction. When the actuator shaft rotates, the potentiometer's adjustable contact changes the door position signal between 0-5 volts.

The HVAC control module uses a range of 0-255 counts to index the actuator position. The door position signal voltage is converted to a 0-255 count range. When the module sets a commanded, or targeted, value, one of the control circuits is grounded. As the actuator shaft rotates the changing position signal is sent to the module. Once the position signal and the commanded value are the same, the module removes power from both control circuits.

Air Temperature Sensors

The air temperature sensors are a 2-wire negative temperature co-efficient thermistor. The vehicle uses the following air temperature sensors

1. Ambient Air Temperature Sensor
2. Inside air temperature sensor assembly
3. Sunload Sensor
4. Upper air temperature sensor
5. Lower air temperature sensor

A signal and low reference circuit enables the sensor to operate. As the air temperature surrounding the sensor increases, the sensor resistance decreases. The sensor signal voltage decreases as the resistance decreases. The sensor operates within a temperature range between -40 to +87.5°C (-40 to +190°F). The sensor signal varies between 0-5 volts.

The input of the duct air temperature sensors are different from the ambient and inside sensors. The HVAC control module converts the signal to a range between 0-255 counts. As the air temperature increases the count value will decrease.

If the HVAC control module detects a malfunctioning sensor, then the control module software will use a defaulted air temperature value. The default value for the inside air temperature sensor will be displayed on the scan tool. The default value for the duct air temperature sensors will not be displayed on the scan tool. The scan tool parameter for the duct air temperature sensors are the actual state of the signal circuit. The default action ensures that the HVAC system can adjust the inside air temperature near the desired temperature until the condition is corrected.

The ambient air temperature sensor mounts underhood and can be affected by city traffic, by idling, and by restarting a hot engine. Therefore, the HVAC control module filters the value of the ambient air temperature sensor for temperature display. The ambient air temperature value is updated under the following conditions

Sunload Sensor

The sunload sensor is a 2-wire photo diode. The vehicle uses left and right sunload sensors. The 2 sensors are integrated into the sunload sensor assembly. Low reference and signal circuits enable the sensor to operate. As the light shining upon the sensor gets brighter, the sensor resistance increases. The sensor signal decreases as the resistance increases. The sensor operates within an intensity range between completely dark and bright. The sensor signal varies between 0-5 volts. The HVAC control module converts the signal to a range between 0-255 counts.

The sunload sensor provides the HVAC control module a measurement of the amount of light shining on the vehicle. Bright, or high intensity, light causes the vehicles inside temperature to increase. The HVAC system compensates for the increased temperature by diverting additional cool air into the vehicle.

If the HVAC control module detects a malfunctioning sensor, then the control module software will use a defaulted sunload value. This value will not be displayed on the scan tool. The default action ensures that the HVAC system can adjust the inside air temperature near the desired temperature until the condition is fixed. The scan tool parameter for the sunload sensor is the actual state of the signal circuit.

A/C Refrigerant Pressure Sensor

The A/C refrigerant pressure sensor is a 3-wire piezoelectric pressure transducer. A 5-volt reference, low reference, and signal circuits enable the sensor to operate. The A/C pressure signal can be between 0-5 volts. When the A/C refrigerant pressure is low, the signal value is near 0 volts. When the A/C refrigerant pressure is high, the signal value is near 5 volts.

The A/C refrigerant pressure sensor protects the A/C system from operating when an excessively high or low pressure condition exists. The engine control module (ECM) disables the compressor clutch under the following conditions

1. The A/C high side pressure is more than 2 929 kPa (425 psi).
2. The clutch will be enabled after the high side pressure decreases to less than 1 376 kPa (200 psi).
3. A/C low side pressure is less than 269 kPa (39 psi).
4. The clutch will be enabled or will allow engagement again after the low side pressure increases to more than 296 kPa (43 psi).

Evaporator Low Ambient Protection

The refrigerant temperature at the temperature sensor on the evaporator case controls cycling of the compressor clutch to prevent freezing of the evaporator core. The compressor is disabled when the temperature goes below 3°C (37°F) and vehicle speed is greater than 8 km/h (5 mph). The compressor is enabled when the temperature exceeds 4°C (40°F). The minimum cycling time off is 4 seconds.

Heating and A/C Operation

The purpose of the heating and A/C system is to provide heated and cooled air to the interior of the vehicle. The A/C system will also remove humidity from the interior and reduce windshield fogging. The vehicle operator can determine the passenger compartment temperature by adjusting the air temperature control. Regardless of the temperature setting, the following can effect the rate that the HVAC system can achieve the desired temperature

1. Recirculation
2. Difference between inside and desired temperature
3. Difference between ambient and desired temperature
4. Blower motor speed setting
5. Mode setting

The vehicle operator can activate the A/C system by pressing the A/C switch. The A/C system can operate regardless of the temperature setting.

The engine control module (ECM) will operate the A/C system automatically in FRONT DEFROST mode to help reduce moisture inside the vehicle. The A/C LED will not illuminate unless the driver presses the A/C request switch on the HVAC control module. The A/C system maybe running without the A/C LED indicator illuminated when in FRONT DEFROST mode. The HVAC system uses a compressor that incorporates a thermal switch that opens once the compressor temperature exceeds 211-217°C (380-454°F) creating an open circuit. The following conditions must be met in order for the ECM to turn on the compressor clutch

1. BCM Battery voltage between 11-16 volts A/C request from the HVAC control module
2. ECM Engine coolant temperature (ECT) is greater than 117°C (243°F). Engine speed is less than 4,760 RPM. A/C pressure is between 2,929-2,706 kPa (425-39 psi).

Once engaged, the compressor clutch will be disengaged for the following conditions

1. Throttle position is 100 percent
2. A/C pressure is more than 2,929 kPa (425 psi).
3. A/C pressure is less than 269 kPa (39 psi).
4. ECT is more than 120°C (248°F).
5. Engine speed is more than 6240 RPM.
6. Transmission shift
7. ECM detects excessive torque load.
8. ECM detects insufficient idle quality.
9. ECM detects a hard launch condition.

When the compressor clutch disengages, the compressor clutch diode protects the electrical system from a voltage spike.

Special Tools

Illustration Tool Number/Description BO-38185 J-38185 Hose Clamp Pliers GE-806 J-33027-A 3-0206952 Holding Wrench GE-8800 J-43600 South America Use Local Equivalent. ACR 2000 Air Conditioning Service Center GE-39400-A J-39400-A South America Use Local Equivalent. Halogen Leak Detector GE-41447 J-41447 South America Use Local Equivalent. R-134A A/C Tracer Dye-Box of 24 GE-42220 J-42220 South America Use Local Equivalent. Universal 12V Leak Detection Lamp GE-43872 J-43872 Fluorescent Dye Cleaner GE-45037 J-45037 South America Use Local Equivalent. A/C Oil Injector GE-45268 J-45268 South America Use Local Equivalent. A/C Flushing Adapter Kit GE-46246 J-46246 South America Use Local Equivalent. Valve Core Tool GE-46297 J-46297 South America Use Local Equivalent. A/C Dye Injector Kit GE-46297-12 J-46297-12 South America Use Local Equivalent. Replacement Dye Cartridges GE-47851 Armature Installer GE-48997 Hybrid Polyolester (POE) Oil Adapter Hose

Scheme 47

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Scheme 51

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Scheme 53

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Scheme 55

Scheme 56

Scheme 57

Scheme 58

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• COMPONENT CONNECTOR END VIEWS - INDEX
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Control Module References
• Diagnostic Repair Verification
• Ambient Air Temperature Sensor Replacement
• Headlamp Automatic Control Ambient Light Sensor Replacement
• Relay Replacement (Within an Electrical Center)
• Relay Replacement (Attached to Wire Harness)
• Checking Aftermarket Accessories
• Noise Diagnosis - HVAC Module
• Noise Diagnosis - Blower Motor
• Odor Diagnosis
• Air Conditioning Clutch Assembly Replacement
• Front Floor Console Accessory Trim Plate Replacement (Lower)
• Fastener Caution
• Actuator Recalibration
• Communication Interface Module Replacement
• DTC B0158
• Air Temperature Description and Operation
• Air Delivery Description and Operation
• Sensor Resistance Table