FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.
Home >> Buick >> 2013 >> Verano L4-2.0L Turbo >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> B Code Charts >> B0509

B0509




DTC B0173, B0178, B0509, B0514 or B3933

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B0173 02
- Upper Left Duct Air Temperature Sensor Circuit Short to Ground

DTC B0173 05
- Upper Left Duct Air Temperature Sensor Circuit High Voltage/Open

DTC B0178 02
- Lower Left Duct Air Temperature Sensor Circuit Short to Ground

DTC B0178 05
- Lower Left Duct Air Temperature Sensor Circuit High Voltage/Open

DTC B0509 02
- Upper Right Duct Air Temperature Sensor Circuit Short to Ground

DTC B0509 05
- Upper Right Duct Air Temperature Sensor Circuit High Voltage/Open

DTC B0514 02
- Lower Right Duct Air Temperature Sensor Circuit Short to Ground

DTC B0514 05
- Lower Right Duct Air Temperature Sensor Circuit High Voltage/Open

DTC B3933 02
- Air Conditioning Evaporator Temperature Sensor Circuit Short to Ground

DTC B3933 05
- Air Conditioning Evaporator Temperature Sensor Circuit High Voltage/Open

Diagnostic Fault Information






Circuit/System Description

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

* Air temperature sensor - left upper

* Air temperature sensor - left lower

* Air temperature sensor - right upper

* Air temperature sensor - right lower

* A/C evaporator temperature sensor

This sensor operates using signal and low reference circuits. As the air temperature surrounding the sensor increases, the sensor resistance decreases. The sensor is capable of reading temperatures ranging from -40 to +115°C (-40 to +240°F), with a signal voltage between 0-5 V. If the HVAC control module detects a malfunctioning sensor the software uses a default air temperature value. The default action ensures that the HVAC system can adjust the inside air temperature near the desired temperature until the condition is corrected.

Conditions for Running the DTC

* Ignition ON.

* The HVAC control module is ON.

Conditions for Setting the DTC

The HVAC control module detects the sensor signal out of range. The signal voltage is less than 0.1 V or greater than 4.9 V for more than 50 ms.

Action Taken When the DTC Sets

The system operates using a default value.

Conditions for Clearing the DTC

The sensor signal is within specified range between 0.1-4.9 V.

Reference Information

Schematic Reference

HVAC Schematics HVAC - Automatic

Connector End View Reference

Component Connector End Views Outside Rearview Mirror - Driver

Description and Operation

Automatic HVAC Description and Operation HVAC - Automatic

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON.

2. Verify the temperature sensor at fault has a parameter displayed in HVAC scan tool information.

• If there is no scan tool parameter
Refer to Circuit/System Testing - Without Scan Tool Support.

• If there is a scan tool parameter

3. Refer to Circuit/System Testing - With Scan Tool Support

Circuit/System Testing

With Scan Tool Support

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate temperature sensor. It may take up to 10 minutes for all vehicle systems to power down.

2. Test for less than 10 ohms between the low reference circuit terminal B and ground.

• If 10 ohms or greater

1. Ignition OFF, disconnect the harness connector at the K33 HVAC control module.

2. Test for less than 2 ohms in the low reference circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K33 HVAC control module control module.

• If less than 10 ohms

3. Ignition ON.

4. Verify the appropriate scan tool Temperature Sensor parameter is less than -37°C (-35°F)

• If greater than -37°C (-35°F)

1. Ignition OFF, disconnect the harness connector at the K33 HVAC control module.

2. Test for infinite resistance between the signal circuit terminal A and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance, replace the K33 HVAC control module.

• If -37°C (-35°F) or less

5. Install a 3 A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B.

6. Verify the scan tool temperature sensor parameter is greater than 110°C (230°F).

• If less than 110°C (230°F)

1. Ignition OFF, disconnect the harness connector at the HVAC control module, ignition ON.

2. Test for less than 1 V between the signal circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V

3. Ignition OFF

4. Test for less than 2 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K33 HVAC control module.

• If 110°C (230°F) or greater

7. Test or replace the temperature sensor.

Without Scan Tool Support

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate temperature sensor. It may take up to 10 minutes for all vehicle systems to power down.

2. Test for less than 10 ohms between the low reference circuit terminal B and ground.

• If 10 ohms or greater

1. Ignition OFF, disconnect the harness connector at the K33 HVAC control module.

2. Test for less than 2 ohms in the low reference circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K33 HVAC control module control module.

• If less than 10 ohms

3. Test for 4.8-5.2 V between the signal circuit terminal A and ground.

• If less than 4.8 V

1. Ignition OFF, disconnect the harness connector at the K33 HVAC control module.

2. Test for infinite resistance between the signal circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance

3. Test for less than 2 ohms in the signal circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the K33 HVAC control module control module.

• If greater than 5.2 V

1. Ignition OFF, disconnect the harness connector at the K33 HVAC control module, ignition ON.

2. Test for less than 1 V between the signal circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V, replace the K33 HVAC control module.

• If between 4.8-5.2 V

4. Test or replace the temperature sensor.

5. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

6. Verify the DTC does not set.

• If the DTC sets
Replace the K33 HVAC control module.

• If the DTC does not set

7. All OK

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* HVAC Component Replacement Reference Removal and Replacement

* Control Module References Control Module References for HVAC control module replacement, programming and setup

pro multis Credits:Operation CHARM About Operation CHARM