PRE-RELEASE
DTC B0173, B0178, B0509, B0514, B0519, B3583, or B3933
| DTC B0173, B0178, B0509, B0514, B0519, B3583, or B3933 |
| Diagnostic Instructions |
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Perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
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Review
Strategy Based Diagnosis
for an overview of the diagnostic approach.
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Diagnostic Procedure Instructions
provides an overview of each diagnostic category.
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| 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 B0519 02
Rear Upper Duct Air Temperature Sensor Circuit Short to Ground
DTC B0519 05
Rear Upper Duct Air Temperature Sensor Circuit High Voltage/Open
DTC B3583 02
Rear Lower Duct Air Temperature Sensor Circuit Short to Ground
DTC B3583 05
Rear Lower 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
| Circuit/System Description |
The air temperature sensors are a 2-wire negative temperature co-efficient thermistor. The vehicle uses the following air temperature sensors:
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Air temperature sensor - left upper
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Air temperature sensor - left lower
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Air temperature sensor - right upper
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Air temperature sensor - right lower
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Air temperature sensor - rear upper (only with CJ4)
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Air temperature sensor - rear lower (only with CJ4)
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A/C evaporator temperature sensor
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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 +85°C (-40 to +185°F). The sensor signal varies between 0-5 V. 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 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 |
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Ignition ON.
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The HVAC control module is ON.
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| 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
Connector End View Reference
Component Connector End Views
Description and Operation
Automatic HVAC Description and Operation
Electrical Information Reference
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Circuit Testing
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Connector Repairs
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Testing for Intermittent Conditions and Poor Connections
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Wiring Repairs
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Scan Tool Reference
Control Module References for scan tool information
| Circuit/System Verification |
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°C (9°F) difference of appropriate Duct Actual parameter value.
| Circuit/System Testing |
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Ignition OFF, disconnect the harness connector at the appropriate temperature sensor.
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Test for less than 10 Ω between the temperature sensor ground circuit terminal B and ground.
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If greater than the specified value, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the K33 HVAC Control Module.
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Ignition ON, test for 4.8-5.2 V between the signal circuit terminal A and ground.
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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 K33 HVAC Control Module.
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If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K33 HVAC Control Module.
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If all circuits test normal, replace the temperature sensor.
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| Repair Instructions |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
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HVAC Component Replacement Reference
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Control Module References
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