DTC Descriptors
DTC B3933 03: Evaporator Temperature Sensor Voltage Below ThresholdDTC B3933 07: Evaporator Temperature Sensor Voltage Above Threshold
Diagnostic Fault Information
Perform the Diagnostic System Check - Vehicle , prior to using this diagnostic procedure.
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Evaporator Temperature Sensor Signal | B0183 03 | B0183 03 | B0183 07 | -- |
Low Reference | -- | B0183 07 | B0183 07 | -- |
Circuit Description
The HVAC control module monitors the evaporator temperature via the evaporator temperature sensor. 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.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The HVAC control module detects the evaporator temperature sensor signal circuit is less than 0.09 volt (5 counts) or greater than 4.90 volts (250 counts).
Action Taken When the DTC Sets
| • | A warning will display on the Driver Information Centre (DIC) "SERVICE A/C SYSTEM" |
| • | The A/C compressor will be disabled. |
Conditions for Clearing the DTC
| • | The condition for setting the DTC is no longer present. |
| • | The history DTC will clear after 50 fault-free ignition cycles. |
| • | The DTC can be cleared with a scan tool. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
| • | Air Delivery Description and OperationAir Temperature Description and Operation |
| • | Air Temperature Description and Operation Air Delivery Description and Operation |
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Ignition ON, using a scan tool, observe the evaporator temperature sensor parameter. The scan tool should display between 0.09 and 4.90 volts.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the evaporator air temperature sensor.
- Ignition OFF, test for less than 10 ohms between the low reference circuit terminal A and ground.
- Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal A and low reference circuit terminal B.
- If all circuits test normal, test or replace the evaporator air temperature sensor.
| ⇒ | 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. |
| ⇒ | If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the HVAC control module. |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HVAC control module. |
Repair Instructions
Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.
