OBD-II Generic Error Code P0937: How to Fix It

Medium 1-3 hours Medium Severity Verified July 2026
Error Code
P0937
Brand
OBD-II Generic
Product Type
automotive
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
1-3 hours
The OBD-II P0937 error code indicates a problem with the hydraulic oil temperature sensor circuit in your vehicle's transmission or hydraulic system. This sensor monitors fluid temperature to help the transmission control module (TCM) make proper shift decisions — when the circuit fails, the TCM can't regulate the system correctly. While this is a medium-severity code, ignoring it can lead to transmission overheating or damage, so prompt diagnosis is recommended.
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Tools You'll Need

How to Fix Error Code P0937

  1. Read and Record All Fault Codes

    Do not clear codes without first recording all of them. You may lose critical diagnostic data needed for accurate repairs.
  2. Check the Hydraulic Transmission Fluid Level and Condition

    Hot transmission fluid can cause serious burns. Allow the vehicle to cool slightly before handling fluid. Wear gloves and safety glasses.
  3. Inspect the Hydraulic Oil Temperature Sensor Wiring and Connector

    Always disconnect the negative battery terminal before probing connectors or handling wiring to avoid short circuits or accidental airbag deployment.
  4. Test the Hydraulic Oil Temperature Sensor Resistance

    Perform resistance testing with the ignition off and the sensor connector unplugged to get accurate readings and avoid damaging the multimeter.
  5. Check the Reference Voltage and Ground at the Connector

    Be careful when back-probing connectors. Do not force probes into tight terminals — use proper back-probe pins to avoid damaging the connector.
  6. Inspect Wiring Between the Sensor and the TCM

    When routing repaired wiring, keep it away from heat sources and moving parts. Use proper automotive-grade wire and connectors for long-lasting repairs.
  7. Replace the Hydraulic Oil Temperature Sensor If Faulty

    Use a drain pan to catch any fluid that escapes when removing the sensor. Dispose of used transmission fluid responsibly at an automotive recycling center. Do not overtighten the sensor — it can crack or strip the housing.
  8. Clear Codes and Perform a Test Drive

Parts You May Need

Hydraulic oil temperature sensor
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Transmission fluid
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Wiring harness repair kit
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Electrical contact cleaner
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Sensor connector pigtail
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Hydraulic oil temperature sensor
Check Price on Amazon
Transmission fluid
Check Price on Amazon
Wiring harness repair kit
Check Price on Amazon
Electrical contact cleaner
Check Price on Amazon
Sensor connector pigtail
Check Price on Amazon
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When to Call a Professional

You should consult a professional mechanic or transmission specialist if: the wiring harness requires extensive repair or routing through the firewall; the fault traces back to the Transmission Control Module (TCM) itself, which requires specialized reprogramming tools; the transmission fluid is severely burnt and a full fluid flush or transmission service is needed; you are uncomfortable working near transmission components or tracing electrical circuits; or if P0937 returns after a sensor and wiring repair, suggesting an internal transmission issue or TCM failure.

Frequently Asked Questions

Can I drive my car with a P0937 code?
You can often drive short distances with a P0937 code, but it is not recommended for extended driving. The hydraulic oil temperature sensor helps the TCM protect the transmission from overheating. Without accurate temperature data, the transmission may not receive proper cooling adjustments, increasing the risk of overheating and long-term damage. Get it diagnosed and repaired as soon as possible.
What causes a P0937 code?
P0937 is most commonly caused by a failed hydraulic oil temperature sensor, damaged or corroded wiring and connectors in the sensor circuit, low or degraded transmission fluid, a short or open circuit in the wiring harness, or in rare cases, a faulty Transmission Control Module (TCM). Wiring issues and sensor failures are by far the most frequent culprits.
How much does it cost to fix a P0937 code?
If it's a simple sensor replacement, parts typically cost between $20 and $80 depending on the vehicle, and labor at a shop may add $75 to $150. Wiring repairs vary widely based on the extent of damage. If the TCM needs replacement or reprogramming, costs can range from $300 to $1,000 or more. DIY repairs can significantly reduce costs if you have the tools and skills.
Will P0937 cause my transmission to shift badly?
Yes, it can. The hydraulic oil temperature sensor data is used by the TCM to determine safe operating conditions and shift strategies. A faulty sensor signal may cause erratic shifting, delayed shifts, the transmission to enter a failsafe or limp mode, or harsh gear changes. Fixing P0937 typically restores normal shift behavior.
Is P0937 the same on all vehicles?
The P0937 code definition — Hydraulic Oil Temperature Sensor Circuit — is standardized across OBD-II compliant vehicles, but the exact sensor location, wiring configuration, resistance specifications, and repair procedures vary by make and model. Always refer to a vehicle-specific service manual or a reputable online service database for accurate specifications before performing repairs.