BMW DTC P0939 – Hydraulic Oil Temperature Sensor Circuit Low
DTC P0939 meaning on BMW
DTC P0939 on a BMW refers to the Hydraulic Oil Temperature Sensor Circuit Low. This diagnostic trouble code indicates that the signal from the hydraulic oil temperature sensor is below the expected range.
BMW DTC P0939 symptoms
Symptoms of DTC P0939 on a BMW may include:
- Check Engine Light illuminated on the dashboard
- Inaccurate temperature readings on the instrument cluster
- Issues with the transmission shifting smoothly
BMW DTC P0939 causes
Common causes of DTC P0939 on a BMW include:
- Faulty hydraulic oil temperature sensor
- Wiring or connector issues in the sensor circuit
- Low hydraulic oil level
BMW DTC P0939 seriousness
While DTC P0939 may not cause immediate drivability issues, it is important to address this code promptly to prevent potential damage to the transmission system. Ignoring this code could lead to more severe problems in the long run.
How to diagnose DTC P0939 on BMW
To diagnose DTC P0939 on a BMW, you can follow these steps:
- Use a diagnostic scanner to retrieve the fault codes stored in the vehicle’s computer.
- Inspect the hydraulic oil temperature sensor and its wiring for any visible damage or corrosion.
- Check the hydraulic oil level and quality to ensure it meets the manufacturer’s specifications.
How to fix DTC P0939 on BMW
To fix DTC P0939 on a BMW, you can try the following:
- Replace the faulty hydraulic oil temperature sensor if it is determined to be the cause of the issue.
- Repair any damaged wiring or connectors in the sensor circuit.
- Top up the hydraulic oil to the correct level and ensure it is of the recommended quality.
How to erase DTC P0939 on BMW
To erase DTC P0939 on a BMW, you can use a diagnostic scanner to clear the fault codes stored in the vehicle’s computer. Once the codes are cleared, you can drive the vehicle and monitor if the Check Engine Light reappears. If the issue has been successfully resolved, the code should not return.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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