HVAC System - Automatic Chevrolet Corvette C6

Fastener Tightening Specifications

Sensor Resistance Table (Air Temperature Duct Sensor)

Sensor Resistance Table (Inside and Ambient Air Temp Sensor)

Scheme 15

Scheme 16

Scheme 17

Scheme 18

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/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 air temperature through air temperature sensors. When the air is cold, the sensor resistance and signal voltage are high. When the air is warm, the sensor resistance and signal voltage are low. The HVAC control module requests A/C compressor clutch engagement and controls the appropriate mode and air temperature actuator door positions in order to maintain the selected air temperature on the HVAC control module.

The inside air temperature sensor provides the HVAC control module with the temperature of the air drawn through an aspirator from the passenger compartment across a sensor. A reference voltage is supplied to the sensor thermistor and the HVAC control module determines the voltage drop across that device which is proportional to temperature. As the air temperature increases, the resistance decreases and the voltage signal decreases. As the air temperature decreases, the resistance increases and the voltage signal increases.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The HVAC control module detects the air temperature sensor signal circuit is less than 2 counts or greater than 253 counts for 30 seconds.

Action Taken When the DTC Sets

A default value will be used for the sensor data by the HVAC control module.

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 50 fault-free ignition cycles.

Reference Information

Schematic Reference

HVAC Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Automatic HVAC Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

B0159, B0174, B0179, B0510, B0515

1. Ignition OFF, disconnect the harness connector at the appropriate temperature sensor.
2. Ignition OFF, test for less than 10.0 ohms between the 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 appropriate scan tool Temp. Sensor parameter is greater than 250 counts. If less 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.
4. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the appropriate scan tool Temp. Sensor parameter is less than 5 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.
5. If all circuits test normal, test or replace the temperature sensor.

B0164

1. Ignition OFF, disconnect the harness connector at the inside air temperature sensor.
2. Ignition OFF, test for less than 10.0 ohms between the low reference circuit terminal 3 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 Inside Air Temp. Sensor parameter is greater than 250 counts. If less 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 ground. Verify the scan tool Inside Air Temp. Sensor parameter is less than 5 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.
5. If all circuits test normal, test or replace the inside air temperature sensor.

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Duct Air Temperature Sensor Replacement - Upper Right Side»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
2. «Duct Air Temperature Sensor Replacement - Upper Left Side»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
3. «Duct Air Temperature Sensor Replacement - Lower Left Side»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
4. «Duct Air Temperature Sensor Replacement - Lower Right Side»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
5. «Ambient Air Temperature Sensor Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
6. «Inside Air Temperature Sensor Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
7. «Control Module References»(/chevrolet/corvette/c6-2004-2014/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/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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. Low reference 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 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 passenger compartment when in the Auto mode.

The ignition is ON.

The HVAC control module detects the signal circuit is less than 0.09 volt (5 counts) or more than 4.90 volts (250 counts).

If the DTC sets due to a low voltage condition, the HVAC control module will operate the system as if a maximum sunload condition exists. If the DTC sets due to a high voltage condition, the HVAC control module will operate the system as if a minimum 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 50 fault-free ignition cycles.

Schematic Reference

HVAC Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Automatic HVAC Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the sunload sensor assembly.
2. Test for less than 2.0 ohm between the low reference circuit terminal C 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 Left Sunload Sensor parameter is greater than 250 counts. If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the HVAC control module.
4. Ignition ON, verify the Right Sunload Sensor parameter is greater than 250 counts. If not the specified value, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the HVAC control module.
5. Install a 3A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal C. Verify the Left Sunload Sensor parameter is less than 5 counts. If not the specified value, 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. Install a 3A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal C. Verify the Right Sunload Sensor parameter is less than 5 counts. If not the specified value, 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 sunload sensor assembly.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Sun Load Temperature Sensor Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/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/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The actuator is an electronic stepper motor. The HVAC control module supplies power and ground to the actuator. The HVAC control module controls the direction of the actuator by changing the polarity of the control circuits. When the actuator reaches its desired position, both circuits are fixed to the same value 0 volts. The HVAC control module determines the door or mode film position by counting pulses, voltage fluctuations, caused by the brush to commutator action generated during normal motor operation. The HVAC control module monitors a voltage drop across an internal resistance to detect the pulses. The HVAC control module converts the pulses to counts with a range of 0-255 counts.

When a calibration or recalibration procedure is performed, the HVAC control module calculates the door or mode film travel range. The HVAC control module commands the actuator in one extreme position then counts pulses starting from 0 counts. The HVAC control module compares the total number of pulses to calibrated limits. If the total pulse count is less than or equal to the maximum calibrated limit and greater than or equal to the minimum calibrated limit, then the calibration is considered successful.

1. Air flow control 3 circuit refers to the mode actuator.
2. Air flow control 7 circuit refers to the recirculation actuator.
3. Temperature control 1 circuit refers to the left air temperature.
4. Temperature control 2 circuit refers to the right air temperature.

1. The ignition is ON.
2. Ignition voltage is between 9-16 volts.
3. 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 7 counts or greater than 250 counts.

Driver A and driver B circuits are deactivated for the appropriate actuator.

1. The DTC will become history if the HVAC control module no longer detects a failure.
2. The history DTC will clear after 50 fault-free ignition cycles.

Schematic Reference

HVAC Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Automatic HVAC Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Engine running, select HVAC manual operation, command the air to flow through the vent outlets, floor outlets, defrost outlets by using the appropriate mode switch on the HVAC control module. The air flow should follow the commanded states and blow through the vent, floor and defrost outlets.
2. Command the air temperature from the full COLD to the full HOT by using the temperature control switch on the HVAC control module. The air temperature should follow the commanded states of full HOT to full COLD through the vent or panel positions.
3. Ignition ON, observe the operation of the drive shaft of the recirculation actuator while using the recirculation control switch on the HVAC control module. The drive shaft of the recirculation actuator should rotate.

1. Ignition OFF, disconnect the harness connector at the appropriate actuator.
2. Ignition ON, connect a test lamp between the control circuit terminal A and control circuit terminal B or C (mode actuator). Command the actuator in each direction. The test lamp should briefly illuminate when commanding the actuator in one direction to the other direction. If the test lamp is always OFF, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HVAC control module. If the test lamp continuously illuminates, test the appropriate control circuit for a short to B+. If the circuit tests normal, replace the HVAC control module.
3. If all circuits test normal, test or replace the appropriate actuator.

Component Testing

1. Install a 10-amp fused jumper wire between the control terminal A and 12 volts. Momentarily install a jumper wire between the control terminal B or C (mode actuator) and ground. The appropriate actuator shaft should rotate. If the function does not perform as specified, replace the appropriate actuator.
2. Reverse the jumper wires; the appropriate actuator shaft should rotate. If the function does not perform as specified, replace the appropriate actuator.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Air Inlet Valve Actuator Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
2. «Mode Valve Actuator Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
3. «Control Module References»(/chevrolet/corvette/c6-2004-2014/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/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/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 causing the A/C refrigerant pressure sensor signal to the ECM to vary. When the pressure is high, the signal voltage is high. When the pressure is low, the signal voltage is low. When 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. Any of the conditions for setting the DTC are met for 15 seconds

P0532

The ECM detects that the A/C pressure is less than 0 psi.

P0533

The ECM detects that the A/C pressure is more than 428 psi.

1. The malfunction indicator lamp (MIL) will not illuminate.
2. The ECM stores the DTC in the Failure Records.
3. The A/C compressor clutch is disabled.

1. The DTC will become history if the ECM no longer detects a failure.
2. The history DTC will clear after 40 consecutive ignition cycles have occurred without a malfunction.
3. The DTC can be cleared by using the scan tool.

Diagnostic Aids

Test the following conditions

1. Visually inspect the sensor for contamination or damage.
2. Inspect for the following that may affect the sensors accuracy: A malfunction within the refrigerant system causing high pressure Visually inspect the A/C components and lines for damage.

Schematic Reference

HVAC Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Automatic HVAC Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Ignition ON, with the engine OFF. Observe the scan tool A/C Refrigerant Pressure parameter. The reading should be between 4.8-5.2 volts and change with A/C pressure.

1. Ignition OFF, disconnect the harness connector at the A/C refrigerant pressure sensor.
2. Ignition OFF, test for less than 1.0 ohm of resistance 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 Refrigerant Pressure parameter is greater than 5.2 volts. If less than the specified range, test the signal circuit terminal for a short to ground. If the circuit tests normal, replace the ECM.
5. Install a 3-amp fused jumper wire between the signal circuit terminal 3 and the low reference circuit terminal 1. Verify the scan tool A/C Refrigerant Pressure parameter is less than 4.8 volt. 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 ECM.
6. If the circuit tests normal, replace the A/C refrigerant pressure sensor.

1. Install a 3-amp fused jumper harness between the 5-volt reference circuit terminal 2 and 5 volts. Install a jumper wire between the low reference terminal 1 and ground.
2. Sweep the sensor through the entire range while monitoring the voltage between the signal terminal 3 and the low reference terminal 1. The voltage should vary between 4.8 and 5.2 volts without any spikes or dropouts. If the voltage is not within the specified range or is erratic, replace the A/C refrigerant pressure sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming
2. «Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Ignition voltage is supplied directly to the air conditioning (A/C) compressor clutch relay. The engine control module (ECM) controls the relay by grounding the A/C clutch relay control circuit.

1. The ignition voltage is between 9-18 volts.
2. The engine speed is greater than 80 RPM.
3. The ECM A/C Compressor Clutch Relay Control transitions between ON to OFF or from OFF to ON.

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

Description and Operation

Automatic HVAC Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition OFF, disconnect the A/C COMP relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal H8 and ground. If the test lamp illuminates, test the control circuit for a short to voltage.
3. Verify that a test lamp illuminates between the ignition circuit terminal F9 and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and ignition circuit fuse is open, test or replace the relay.
4. Connect a test lamp between the ignition circuit terminal F9 and the control circuit terminal H8.
5. Command the A/C relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM. If the test lamp is always OFF, test the control circuit for a short to voltage, 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 COMP relay.

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. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/corvette/c6-2004-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/corvette/c6-2004-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)
2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for ECM replacement, setup, and programming

Symptoms - HVAC Systems - Automatic

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) before using the Symptom Tables in order to verify that all of the following are true: There are no DTCs set. The control modules can communicate via the serial data link.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to the following information: «Automatic HVAC Description and Operation»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the HVAC System. Refer to «Checking Aftermarket Accessories»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__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. Verify that the customer is using the correct key to enable personalization and is not inadvertently activating auxiliary HVAC controls.
5. The A/C compressor will not operate in cold outside air temperatures.
6. The following conditions may 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
7. 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/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
2. «Blower Motor Malfunction»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
3. «Air Temperature Malfunction»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
4. «Leak Testing»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
5. «Noise Diagnosis - Blower Motor»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__noise-diagnosis-blower-motor)
6. «Noise Diagnosis - Air Conditioning (A/C) System»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__noise-diagnosis-air-conditioning-ac)
7. «Odor Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning__odor-diagnosis)

1. Perform the «Diagnostic System Check - Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/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 module grounds the A/C request signal circuit. This input will request the engine control module (ECM) to ground the A/C compressor clutch relay control circuit, which will switch the A/C COMP 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 9-18 volts.
2. Engine coolant temperature (ECT) is less than 123°C (253°F).
3. Engine speed is less than 4,760 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

Description and Operation

Automatic HVAC Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

Engine running, observe the function of the A/C compressor clutch while commanding the A/C relay ON and OFF with a scan tool. The A/C compressor clutch should engage and disengage.

1. Ignition OFF, disconnect the A/C COMP relay.
2. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal H9 and ground. If the test lamp illuminates, test the control circuit for a short to voltage.
3. Verify that a test lamp illuminates between the ignition circuit terminal F9 and ground. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test or replace the A/C COMP relay.
4. Verify that a test lamp illuminates between the B+ circuit terminal F8 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 is open, test the control circuit terminal for a short to ground.
5. Disconnect the harness connector at the A/C compressor clutch.
6. Test for less than 1.0 ohm between the ground circuit terminal A and ground. If greater than the specified range, test the ground circuit for an open/high resistance.
7. Connect the harness connector at the A/C compressor clutch.
8. Connect a 10A fused jumper wire between the B+ circuit terminal F8 and the control circuit terminal H9. Verify the A/C compressor clutch is activated. If the A/C compressor clutch does not activate, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the A/C compressor clutch.
9. Connect a test lamp between the ignition circuit terminal F9 and the control circuit terminal H8.
10. Command the A/C relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states. If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM. If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
11. If all circuits test normal, test or replace the A/C COMP relay.

Relay Test

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. «Relay Replacement (Attached to Wire Harness)»(/chevrolet/corvette/c6-2004-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction) or «Relay Replacement (Within an Electrical Center)»(/chevrolet/corvette/c6-2004-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-introduction)
2. «Air Conditioning Compressor Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
3. «Control Module References»(/chevrolet/corvette/c6-2004-2014/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/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

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 and ground circuits enable the control processor to operate. The HVAC control module provides a pulse width modulation (PWM) signal to the blower motor speed 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 as a low side control to adjust the blower motor speed.

Schematic Reference

HVAC Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Automatic HVAC Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__wiring-repairs)

Scan Tool Reference

Control Module References for scan tool information

1. Ignition ON, command the blower motor ON and OFF with a scan tool, the blower motor should turn ON and OFF when changing between the commanded states.
2. Observe the scan tool Blower Motor Speed parameter while changing the blower motor switch from Off through to the High speed positions. The display should change from 0-100 percent. If the display does not change, replace the HVAC control module.

1. Ignition OFF, disconnect the harness connector at the blower motor control processor.
2. Test for less than 1.0 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 that a test lamp illuminates between B+ and the 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 and the B+ circuit fuse is open, replace the blower motor control processor.
4. Connect a DMM between B+ and the control circuit terminal B.
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 ground. 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 voltage 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. If all circuits test normal, replace the blower motor control processor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Blower Motor Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning)
2. «Control Module References»(/chevrolet/corvette/c6-2004-2014/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/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/chevrolet/corvette/c6-2004-2014/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The HVAC control module supplies inside and ambient air temperature sensors with a low reference circuit and 5-volt signal circuit. The inside air temperature sensor has a fan motor that operates using body ground and a 12-volt supply from the body control module (BCM) when the ignition and HVAC control module are ON. The HVAC control module determines the voltage drop across the sensors, 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.

Schematic Reference

HVAC Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Automatic HVAC Description and Operation

Electrical Information Reference

1. «Circuit Testing»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__circuit-testing)
2. «Connector Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis)
4. «Wiring Repairs»(/chevrolet/corvette/c6-2004-2014/remont/body-electrical/#wiring-systems-and-power-management-service-troubleshooting-diagnosis__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 «Sunload Sensor Circuit Malfunction»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic__sunload-sensor-circuit-malfunction) .
2. Measure actual outside air temperature using a thermometer. Compare this value to the scan tool Ambient Air Temp. Sensor 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»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic__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. 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»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic__inside-air-temperature-sensor-circuit-malfunction) .
4. Measure actual air temperature using a thermometer at each duct temperature sensor. Compare this value to the appropriate scan tool Duct Temp. Sensor parameter. The measured temperature should be within 5 degrees of parameter. If not within the specified range, refer to «Duct Temperature Sensor Circuit Malfunction»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic__duct-temperature-sensor-circuit-malfunction) .

Sunload Sensor Circuit Malfunction

1. Ignition OFF, disconnect the harness connector at the sunload sensor assembly.
2. Test for less than 2.0 ohm between the low reference circuit terminal C 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 Left Sunload Sensor parameter is greater than 250 counts. If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the HVAC control module.
4. Ignition ON, verify the Right Sunload Sensor parameter is greater than 250 counts. If not the specified value, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the HVAC control module.
5. Install a 3A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal C. Verify the Left Sunload Sensor parameter is less than 5 counts. If not the specified value, 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. Install a 3A fused jumper wire between the signal circuit terminal B and the low reference circuit terminal C. Verify the Right Sunload Sensor parameter is less than 5 counts. If not the specified value, 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 sunload sensor assembly.

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 10.0 ohms between the 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 Ambient Air Temp. Sensor parameter is greater than 250 counts. If less 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.
4. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the appropriate Ambient Air Temp. Sensor parameter is less than 5 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.
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. Ignition ON, verify a test lamp illuminates between the ignition circuit terminal 1 and ground. If the test lamp does not illuminate, test the ignition circuit for short to ground or an open/high resistance.
3. Ignition ON, HVAC control module ON. Verify that a test lamp illuminates between the ignition circuit terminal 1 and the control circuit terminal 3. If the test lamp does not illuminate, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
4. Ignition OFF, test for less than 10.0 ohms between the low reference circuit terminal 3 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 the scan tool Inside Air Temp. Sensor parameter is greater than 250 counts. If less 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.
6. Install a 3A fused jumper wire between the signal circuit terminal 1 and ground. Verify the scan tool Inside Air Temp. Sensor parameter is less than 5 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.
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 temperature sensor.
2. Ignition OFF, test for less than 10.0 ohms between the 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 appropriate scan tool Temp. Sensor parameter is greater than 250 counts. If less 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.
4. Install a 3A fused jumper wire between the signal circuit terminal A and ground. Verify the appropriate scan tool Temp. Sensor parameter is less than 5 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.
5. If all circuits test normal, test or replace the temperature sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Duct Air Temperature Sensor Replacement - Upper Right Side»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
2. «Duct Air Temperature Sensor Replacement - Upper Left Side»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
3. «Duct Air Temperature Sensor Replacement - Lower Left Side»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
4. «Duct Air Temperature Sensor Replacement - Lower Right Side»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
5. «Ambient Air Temperature Sensor Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
6. «Inside Air Temperature Sensor Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
7. «Sun Load Temperature Sensor Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic)
8. «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for HVAC control module replacement, setup, and programming

Afterblow Enabling

The afterblow mode can be enabled using the scan tool. The afterblow mode allows the blower motor to operate after the engine has been turned off. This operation of the blower motor dries the evaporator core, which reduces the amount of microbial growth which can create undesirable odors.

Use the following procedure in order to enable the afterblow mode

1. Connect the scan tool.
2. Turn ON the ignition, with the engine OFF.
3. Select HVAC Module.
4. Select HVAC Systems Automatic.
5. Select Special Functions.
6. Select HVAC.
7. Select Afterblow Option.
8. Select ENTER to enable the afterblow.
9. When done, use the soft key to save changes.

When afterblow has been enabled by the scan tool the blower motor will operate between medium and high speed for 4 minutes after the engine has been turned off.

The following conditions must be met for the HVAC module to operate the afterblow

1. The outside air temperature must be at least 21°C (70°F).
2. The A/C compressor must operate for more than 2 minutes.
3. The engine must be turned off for at least 45 minutes.
4. The system voltage must be at least 12 volts.

Calibration Procedure with a Scan Tool

Use the following steps to perform the calibration update

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. With a scan tool, select HVAC Systems Automatic.
4. Select Special Functions.
5. Select HVAC.
6. Select Calibrate HVAC Module.
7. Select ON, wait 30 seconds.

Calibration Procedure without a Scan Tool

1. Turn OFF the ignition.
2. Remove the battery positive voltage circuit fuse of the HVAC control module.
3. Wait 60 seconds.
4. Install the fuse.

Removal Procedure

1. Remove the instrument panel (I/P) accessory trim plate. Refer to «Instrument Panel Accessory Trim Plate Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
2. Remove the HVAC control module retaining screws.
3. Remove the HVAC control module.
4. Disconnect the HVAC control module electrical connections.

Installation Procedure

1. Connect the HVAC control module electrical connections.
2. Install the HVAC control module to the I/P trim plate.
3. Install the HVAC control module retaining screws. Tighten: Tighten the screws to 1.9 N.m (17 lb in).
4. Connect the electrical connectors to the HVAC control module.
5. Install the I/P accessory trim plate. Refer to «Instrument Panel Accessory Trim Plate Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
6. Start and allow the engine to run for at least one minute.
7. Refer to «Control Module References»(/chevrolet/corvette/c6-2004-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for programming and setup information.

1. Remove the RH lower insulator panel. Refer to «Instrument Panel Insulator Panel Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
2. Disconnect the HVAC module wiring harness from the recirculation housing wire harness retainer.
3. Remove the recirculation actuator mounting screws.
4. Remove the recirculation actuator.
5. Disconnect the electrical connector from the recirculation actuator.

1. Connect the recirculation actuator electrical connector.
2. Install the recirculation actuator. Install the recirculation actuator mounting screws. Tighten: Tighten the screws to 1.6 N.m (14 lb in).
3. Connect the HVAC module wiring harness to the recirculation housing wire harness retainer.
4. Install the RH lower insulator panel. Refer to «Instrument Panel Insulator Panel Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .

1. Remove the SIR bracket. Refer to «Instrument Panel Inflatable Restraint Module Bracket Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
2. Disconnect the mode actuator electrical connector.
3. Remove the mode actuator mounting screws.
4. Remove the mode actuator.

1. Install the mode actuator.
2. Install the mode actuator mounting screws. Tighten: Tighten the screws to 1.6 N.m (14 lb in).
3. Connect the mode actuator electrical connector.
4. Install the SIR bracket. Refer to «Instrument Panel Inflatable Restraint Module Bracket Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
5. Recalibrate the actuators. Refer to «Actuator Recalibration»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic) .

1. Remove the SIR bracket. Refer to «Instrument Panel Inflatable Restraint Module Bracket Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
2. Disconnect the RH air temperature actuator electrical connector.
3. Remove the RH air temperature actuator mounting screws.
4. Remove the RH air temperature actuator.

1. Install the RH air temperature actuator.
2. Install the RH air temperature actuator mounting screws. Tighten: Tighten the screws to 1.6 N.m (14 lb in).
3. Connect the RH air temperature actuator electrical connector.
4. Install the SIR bracket. Refer to «Instrument Panel Inflatable Restraint Module Bracket Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
5. Recalibrate the actuators. Refer to «Actuator Recalibration»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic) .

1. Remove the instrument panel (I/P) cluster assembly. Refer to «Instrument Cluster Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges) .
2. Disconnect the electrical connector from the left air temperature actuator.
3. Remove the actuator mounting screws.
4. Remove the actuator.

1. Install the left air temperature actuator.
2. Install the actuator mounting screws. Tighten: Tighten the screws to 1.6 N.m (14 lb in).
3. Connect the actuator electrical connector.
4. Install the I/P cluster assembly. Refer to «Instrument Cluster Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges) .
5. Recalibrate the actuators. Refer to «Actuator Recalibration»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#hvac-system-automatic) .

1. Remove the instrument panel (I/P) assembly. Refer to «Instrument Panel Assembly Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
2. Disconnect the right upper air temperature sensor electrical connector.
3. Remove the right upper air temperature sensor from the air distribution duct.

1. Install the right upper air temperature sensor to the air distribution duct.
2. Connect the right upper air temperature sensor electrical connector.
3. Install the I/P assembly. Refer to «Instrument Panel Assembly Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .

1. Remove the instrument panel cluster (IPC). Refer to «Instrument Cluster Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges) .
2. Disconnect the left upper air temperature sensor electrical connector.
3. Remove the left upper air temperature sensor from the air distribution duct.

1. Install the left upper air temperature sensor to the air distribution duct.
2. Connect the left upper air temperature sensor electrical connector.
3. Install the IPC. Refer to «Instrument Cluster Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges) .

1. Remove the HVAC module. Refer to «HVAC Module Assembly Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Disconnect the lower LH diagnostic test mode (DTM) sensor electrical connector.
3. Remove the lower LH DTM sensor from the HVAC module.

1. Install the lower LH DTM sensor to the HVAC module.
2. Connect the lower LH DTM sensor electrical connector.
3. Install the HVAC module. Refer to «HVAC Module Assembly Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

1. Remove the HVAC module. Refer to «HVAC Module Assembly Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Disconnect the lower RH DTM sensor electrical connector.
3. Remove the lower RH DTM sensor from the HVAC module.

1. Install the lower RH DTM sensor to the HVAC module.
2. Connect the lower RH DTM sensor electrical connector.
3. Install the HVAC module. Refer to «HVAC Module Assembly Replacement»(/chevrolet/corvette/c6-2004-2014/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/corvette/c6-2004-2014/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
2. Disconnect the ambient air temperature sensor electrical connector.
3. Remove the push-in retainer securing the ambient air temperature sensor to the lower RH side of the radiator support.
4. Remove the ambient air temperature sensor from the radiator support.

1. Install the ambient air temperature sensor to the lower radiator support.
2. Install the push-in retainer to secure the ambient air temperature sensor to the radiator support.
3. Connect the ambient air temperature sensor electrical connector.

1. Remove the knee bolster. Refer to «Driver Knee Bolster Panel Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .
2. Remove the driver information center (DIC) retaining screw.
3. Disconnect DIC from the instrument panel (I/P).
4. Disconnect the inside air temperature sensor from the DIC bezel.
5. Disconnect the inside air temperature sensor electrical connector.

1. Connect the inside air temperature sensor electrical connector.
2. Install the inside air temperature sensor.
3. Connect DIC to the I/P.
4. Install the DIC retaining screw. Tighten: Tighten the screw to 1.9 N.m (17 lb in).
5. Install the knee bolster. Refer to «Driver Knee Bolster Panel Replacement»(/chevrolet/corvette/c6-2004-2014/remont/gauges-instrument-panels/#instrument-panel-trim-and-console-trim) .

Scheme 19

HVAC Control Module

The HVAC control module is a class 2 device that interfaces between the operator and the HVAC system to maintain air temperature and distribution settings. The battery positive voltage circuit provides power that the control module uses for keep alive memory (KAM). If the battery positive voltage circuit loses power, all HVAC DTCs and settings will be erased from KAM. The body control module (BCM), which is the vehicle power mode master, provides a device on signal. The control module supports the following features

Personalization

The HVAC control module will receive information that defines the current driver of the vehicle from the driver door module (DDM) through class 2 communication. The HVAC system will memorize the following system configurations for up to three unique drivers

1. Driver set temperature
2. Passenger set temperature
3. Mode
4. Blower motor speed (auto, speed 1, 2, 3, 4, 5, 6)
5. A/C compressor request, auto ON or A/C OFF

This information shall be stored inside the HVAC control module memory. When a different driver identification button is selected the HVAC control module will recall the appropriate driver settings. When the HVAC control module is first turned on, the last stored settings for the current driver will be activated except for the rear defrost and heated seat settings.

Air Temperature, Mode and Recirculation Actuators

The actuators are 2 wire bi-directional electric motors. Two control circuits enable the actuator to operate. The control circuits use either a 0 or 12 volt value to co-ordinate the actuator movement. When the actuator is at rest, both control circuits have a value of 12 volts. In order to move the actuator, the HVAC control module grounds the appropriate control circuit for the commanded direction. The HVAC control module reverses the polarity of the control circuits to move the actuator in the opposite direction.

The HVAC control module determines the door position by counting motor pulses on one of the control circuits. These pulses are small voltage fluctuations that occur when the brush is shorted across two commutator contacts as the motor rotates. As the actuator shaft rotates, the HVAC control module monitors the voltage drop across an internal resistance to detect the pulses. The HVAC control module converts the pulses to counts with a range of 0 to 255 counts. The HVAC control module uses a range of 0-255 counts to index the actuator position.

Air Temperature Sensors

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

1. Outside
2. Inside
3. Upper right
4. Upper left
5. Lower right
6. Lower left

The upper and lower duct sensors are divided into left and right zone operation. The left side upper and lower duct sensors will only effect the operation of the left air temperature actuator and the right side upper and lower duct sensors will only effect the operation of the right air temperature actuator. The duct sensors are used to measure the temperature of the air exiting the ducts. The sensors operate within a temperature range between -6.5°C (20.3°F) to 57.5°C (135.5°F). When temperature increases the sensor signal decreases. The HVAC control module converts the 0-5 volt sensor signal to a range between 0-255 counts. If the HVAC control module detects that one of the duct temperatures must change, the HVAC control module will adjust the appropriate air temperature actuator. The following list shows the duct sensors that are monitored by the HVAC control module in each mode position

If the HVAC control module detects a malfunctioning sensor, the HVAC system will only malfunction when the sensor is monitored.

The inside temperature sensor operates within a temperature range between -6.5°C (20.3°F) to 57.5°C (135.5°F). If the sensor is shorted to ground, an open, or shorted to voltage, the HVAC system will use a default value.

The outside temperature sensor operates within a temperature range between -30°C (-22°F) to 51°C (123.8°F). The radio displays the OAT value that it receives from the HVAC control module through a class 2 message. If the HVAC control module has determined that the outside temperature sensor has failed, the radio shall display, 75, in place of the outside air temperature. If the sensor is shorted to ground, an open, or shorted voltage, the HVAC control module will use a default value.

The radio displays the outside air temperature value that it receives from the HVAC control module through a class 2 message. The scan tool has the ability to update the displayed ambient air temperature. The outside air temperature value is displayed or 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 two sensors are integrated into the sunload sensor assembly along with the ambient light sensor. Low reference 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 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 sensor is open or shorted, the HVAC control module acts as if no sunload condition occurs.

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 prevents the A/C system from operating when an excessively high or low pressure condition exists. The ECM disables the compressor clutch under the following conditions

1. A/C pressure is more than 2850 kPa (413 psi). The clutch will be enabled after the pressure decreases to less than 2100 kPa (254 psi).
2. A/C pressure is less than 204 kPa (30 psi). The clutch will be enabled after the pressure increases to more than 220 kPa (32 psi).

If the ECM detects a failure in the A/C refrigerant pressure sensor or circuit, the class 2 message sent to the HVAC control module will be invalid. The HVAC control module will display A/C OFF on the module as long as the condition is present.

Heating and A/C Operation

The purpose of the heating and A/C system is to provide the following

1. Heated air
2. Cooled air
3. Remove humidity from the interior of the vehicle
4. Reduce windshield fogging

Regardless of the temperature setting, the following can effect the rate that the HVAC system can achieve a desired temperature

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

The HVAC control module commands or monitors the following actions when an air temperature setting is selected.

WARMEST POSITION - The air temperature actuator door position directs maximum air flow through the heater core.

COLDEST POSITION - The air temperature actuator door position directs maximum air flow around the heater core.

BETWEEN THE WARMEST AND COLDEST POSITION - The following sensors are monitored to direct the appropriate amount of air through the heater core to achieve the desired temperature

1. Sunload
2. Outside temperature
3. Inside temperature
4. Duct temperatures

The A/C system is engaged by selecting any switch on the HVAC control module except the, A/C OFF switch. The A/C switch will illuminate, A/C OFF, when the A/C switch is selected. The HVAC control module sends a class 2 A/C request message to the body control module (BCM) for A/C compressor clutch operation. The BCM must communicate with the ECM in order for the A/C clutch to be engaged. The HVAC system uses a compact variable swash plate compressor. The following conditions must be met in order for the ECM to turn on the compressor clutch from the HVAC control module request

1. BCM will allow A/C operation if the following limits are within normal operating range A/C line pressure A/C refrigerant low temperature Ambient temperature Engine coolant temperature Battery voltage
2. HVAC control module OAT temperature more than 1.5°C (35°F) Control module operating range 9 and 16 volts
3. ECM Engine coolant temperature (ECT) is less than 128°C (262°F) Engine RPM is more than 0 RPM A/C pressure is between 2850 kPa (413 psi) and 204 kPa (30 psi).

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

1. Throttle position is 100%
2. A/C pressure is more than 2850 kPa (413 psi)
3. A/C pressure is less than 204 kPa (30 psi)
4. Engine coolant temperature (ECT) is more than 128°C (262°F)

If there is a malfunction in the A/C system, the driver information center will read, SERVICE A/C SYSTEM, to alert the driver.

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

Dual Zone Operation

The HVAC control module has temperature settings for the driver and the passenger. If the passengers setting is turned off then the drivers setting controls both driver and passenger temperature actuators. The passengers setting can not be used without the drivers setting also being ON. The passengers setting can be turned ON or OFF by pressing the temperature switch on the passengers side of the HVAC control module. When the passengers setting is ON, the passenger temperature can be adjusted independently from the drivers setting and the passenger temperature is displayed on the passengers side of the control module. A different sunload or duct temperature on one side of the vehicle may cause different discharge air temperatures even when the passengers setting is not turned ON.

Automatic Operation

In automatic operation, the HVAC control module will maintain the comfort level inside of the vehicle by controlling the A/C compressor clutch, the blower motor, the air temperature actuators, mode actuator and recirculation.

To place the HVAC system in automatic mode, the following is required

1. The blower motor switch must be in the AUTO position.
2. The air temperature switch must be in any other position other than 60 or 90 degrees.
3. The mode switch must be in the AUTO position.

Once the desired temperature is reached, the blower motor, mode, recirculation and temperature actuators will automatically adjust to maintain the temperature selected, except in the extreme temperature positions. The HVAC control module performs the following functions to maintain the desired air temperature

1. Regulate blower motor speed
2. Position the air temperature actuator
3. Position the mode actuator
4. Position the recirculation actuator

When the warmest position is selected in automatic operation the blower speed, based on coolant temperature, will increase gradually until the vehicle reaches normal operating temperature. When normal operating temperature is reached the blower will stay on high speed and the air temperature actuators will stay in the full heat position. When the coldest position is selected in automatic operation the blower will stay on high and the air temperature actuators will stay in the full cold position.

In cold temperatures, the automatic HVAC system will provide heat in the most efficient manner. The vehicle operator can select an extreme temperature setting but the system will not warm the vehicle any faster. In warm temperatures, the automatic HVAC system will also provide air conditioning in the most efficient manner. Selecting an extreme cool temperature will not cool the vehicle any faster.

Air Speed

The blower motor forces air throughout the vehicles interior. The vehicle operator determines the blower motor's speed by toggling the blower motor switch manually or by using the automatic mode. The blower motor will always operate at some speed as long as the HVAC control module is in any position other than OFF, as long as the ignition switch is in the RUN position.

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 PWM signal to the control processor in order to command the blower motor speed. The processor supplies 12volts to the blower motor through the blower motor voltage supply circuit. The control processor uses the blower motor ground as a low side PWM control to adjust the blower motor speed.

Off Mode

When the vehicle is moving, air flowing over the vehicle increases the air pressure just ahead of the windshield. This forces air into the outside air inlet, into the HVAC module and out through the floor outlets. The HVAC control module attempts to match the inside air temperature and driver selected temperatures. Since the A/C compressor is not running, the incoming air may be warmed but not cooled.

Recirculation Mode

The recirculation mode can be used in both automatic and manual operation. The only time recirculation is not available is when FRONT DEFROST and mix blend mode is selected. The RECIRC LED will flash to alert the driver that recirculation mode is not available. Pressing the recirculation switch, from the OFF position, will set the blower, mode and A/C compressor clutch into automatic mode.

When in automatic mode, recirculation will stay on until either the vehicle operator selects outside air, by pressing the RECIRCULATION switch, or the HVAC control module automatically moves the recirculation actuator. Automatic recirculation is only available when air temperatures are 21°C (70°F) or warmer. The recirculation actuator position will vary to obtain a cooler duct air temperature when cool air is selected. This will assist in cooling the vehicle quicker.

The HVAC control module will move the recirculation actuator to the outside air position at ignition off to bring fresh air to replace stale air that has accumulated in the HVAC module during shut down.

When requested the recirculation actuator will be able to move to the 100% recirculation position for a limited time, after that limited time the actuator will move to the 90% position. In the auto mode only, the recirculation actuator will move faster to the recirculation position when vehicle is at an idle compared to the normal speed of the actuator during normal operation.

If the recirculation actuator or related circuits has a failure the HVAC control module will attempt to drive the actuator to the outside air position regardless of mode selection. If there is a failure with one of the air temperature actuators the HVAC control module will allow the recirculation actuator to move to the outside air position.

Automatic Modes

The automatic HVAC system will warm up/cool down and maintain the interior temperature of the vehicle by controlling the A/C compressor clutch, blower motor, air temperature, mode and recirculation actuators to achieve the desired temperature. For fully automatic operation, both the blower and mode buttons must be in the AUTO position. Blower speeds will change automatically based on inputs to the HVAC control module. Only RECIRCULATION will have to be reset after each ignition cycle.

Moisture tends to accumulate in the HVAC module assembly after the engine has been shut off. The HVAC control module will purge the HVAC module of stale air and moisture to prevent window fogging. The mode actuator will move to the floor mode and run the low speed blower for 10 seconds to purge out the air and moisture. The recirculation actuator will be in the outside air position. Purge mode can be bypassed if any manual modes are selected.

In cold temperatures, the automatic HVAC system will provide heat in the most efficient manner. On cold engine start-up, when temperatures are -1°C (30°F) or colder, low blower speeds will be selected and airflow will be directed on the windshield for 3 minutes. This is done to prevent windshield fogging. To warm the interior quickly, maximum heat mode is used where the blower is at maximum speed, floor mode, both air temperature actuators are in full hot position and outside air is being drawn in. The vehicle operator can select the extreme warm setting of 32°C (90°F), but the system will be out of automatic operation and not warm the vehicle any faster or regulate the blower speed. Once the desired temperature is reached, the blower motor, mode, recirculation and temperature will be adjusted automatically by the HVAC control module.

In warm temperatures, the automatic HVAC system will provide A/C in the most efficient manner. On vehicle start up, the HVAC control module will monitor for conditions that indicate the possible presence of moisture in the HVAC module. To avoid blowing hot air and moisture out at the driver, the HVAC control module moves the mode door toward the floor and runs the low speed blower for a 3 seconds. This purge mode can be bypassed if the vehicle is started with the blower switch in maximum speed position. To cool the interior quickly, maximum cool mode is used where the blower is at maximum speed, both air temperature actuators are in full cold position and the recirculation actuator is drawing air from inside the vehicle. The vehicle operator can select the extreme cool setting of 16°C (60°F), but the system will be out of automatic operation and not cool the vehicle any faster or regulate the blower speed. Once the desired temperature is reached, the blower motor, mode, recirculation and temperature will be adjusted automatically by the HVAC control module.

Front Defrost Mode

The front defrost mode is the only setting that is not controlled by the automatic HVAC system. When defrost is selected, by the vehicle operator, the A/C compressor is activated and outside air is brought into the vehicle. The blower motor will be activated, regardless of coolant temperature and air will be directed toward the windshield, the side windows and some air flow to the floor. Recirculation mode is not available in front defrost. The recirculation LED will flash on their respective displays if any of those switches are pressed when in front defrost mode. This indicates that these modes are not available. The rear window defogger does not affect the HVAC system in any setting.

Special Tools

Illustration Tool Number/Description J 34142-B 12-V Unpowered Test Lamp J 35616-A Connector Test Adapter Kit J 39200 Digital Multimeter 7000081 Tech 2 Kit

Scheme 20

Scheme 21

Scheme 22

Scheme 23

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Component Connector End Views
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Control Module References
• Diagnostic Repair Verification
• Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement
• Relay Replacement (Attached to Wire Harness)
• Checking Aftermarket Accessories
• Noise Diagnosis - Blower Motor
• Noise Diagnosis - Air Conditioning (A/C) System
• Odor Diagnosis
• Instrument Panel Accessory Trim Plate Replacement
• Fastener Caution
• Instrument Cluster Replacement
• Lifting and Jacking the Vehicle
• DTC B0159, B0164, B0174, B0179, B0510, or B0515
• Sunload Sensor Circuit Malfunction
• Ambient Air Temperature Sensor Circuit Malfunction
• Inside Air Temperature Sensor Circuit Malfunction
• Duct Temperature Sensor Circuit Malfunction
• Fastener Tightening Specifications