P0937Generic code

P0937 Code: Hydraulic Oil Temperature Sensor Circuit

The P0937 code means the computer found an electrical fault in the circuit of the hydraulic oil temperature sensor in an automated manual transmission. The main effect is shifting that feels slower or harsher, mostly when the car is cold. The fault is usually in the connector or the wiring, so check those before buying a sensor.

Severity
Medium
Can I keep driving?
Yes, but with caution
Estimated cost
$40 to $400
Difficulty
Medium
System
Transmission
Applies to
All OBD2 vehicles

Updated Reviewed by Renzo Chacca

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What the P0937 code means

Automated manual transmissions (Opel Easytronic, Fiat Dualogic, Toyota MMT, BMW SMG, Ford Durashift, Volkswagen ASG) and many dual-clutch gearboxes use electric or hydraulic actuators to release the clutch, pick the gear plane (selection) and engage the gear (engagement). The transmission computer watches every actuator through position sensors. The temperature of the hydraulic fluid changes how thick it is, and the computer uses that temperature to adjust the timing of each actuation.

The sensor changes its resistance as the fluid warms up and the computer reads the resulting voltage. The P0937 code means that circuit is not behaving electrically. The cause can be the sensor, the wiring or the supply to it.

Without this signal the computer falls back on a fixed value, so shifts can come out slower or harsher, especially on a cold start.

Always start with the simple things: fuse, relay and connector. Then check the supply, ground and signal with the component plugged in (use back-probe pins), and finally the continuity of each wire to the computer. Replace the component only if all of that checks out.

P0937 code symptoms

  • Check engine light on.
  • Shifts that are slower or harsher than normal.

Likely causes of the P0937 code

  1. Damaged or corroded connector. The most common cause.
  2. Wiring that is cut or shorted between the sensor and the computer.
  3. Failed sensor. Open or shorted inside.
  4. Missing reference voltage. Check whether other sensors are also out.
  5. Computer. Uncommon, so rule out everything above first.

How to diagnose the P0937 code step by step

  1. Read the sensor value on the scan tool and compare it with the expected temperature.
  2. Inspect the connector for corrosion, water or loose pins.
  3. Check the supply and ground with the key on: the reference should be correct and the ground should drop less than 0.1 volt.
  4. Measure the signal with the connector plugged in and see whether it changes as the fluid warms up.
  5. Do the wiggle test on the harness with the scan tool in graph mode.
  6. Check continuity of each wire to the computer, which should be under 1 ohm.

How to fix the P0937 code

  • Repair the connector or the wiring.
  • Replace the sensor if the tests confirm it is bad.
  • Correct the real condition if there is one.
  • Clear the P0937 code and verify with a road test.

Technical reference data

  • NTC thermistor: its resistance drops as the fluid gets hotter.
  • Reference values only: check the manufacturer data for your vehicle.

Brand-specific notes

Gearboxes of this type are the ones that most often set this code. On many hydraulic systems the actuator fluid is a specific one, and the reservoir should be checked regularly.

P0937 on Opel

Very common on the Opel Easytronic.

P0937 on Fiat

Very common on the Fiat Dualogic.

P0937 on Toyota

Very common on the Toyota MMT.

P0937 on Smart

Very common on Smart cars with this kind of transmission.

P0937 on BMW

Very common on the BMW SMG.

Frequently asked questions about P0937

Can I drive with a P0937 code?
Yes, with caution. Expect slower or rougher shifts, and have the circuit checked before it gets worse.
Does the sensor have to be replaced?
Only if the tests confirm it. The connector and the wiring fail just as often as the sensor does.
What does the hydraulic oil temperature sensor do?
Automated manual transmissions (Opel Easytronic, Fiat Dualogic, Toyota MMT, BMW SMG, Ford Durashift, Volkswagen ASG) and many dual-clutch gearboxes use electric or hydraulic actuators to release the clutch, pick the gear plane (selection) and engage the gear (engagement). The transmission computer watches each actuator with position sensors. The temperature of the hydraulic fluid changes its thickness, and the computer uses it to adjust the timing of each actuation.
How much does it cost to fix P0937?
As a rough guide, between $40 and $400. A connector repair is cheap, and a new sensor with labor costs more.
What does the P0937 code mean?
It means there is an electrical fault in the hydraulic oil temperature sensor circuit. The computer can no longer read the fluid temperature correctly.
What is the most common cause of P0937?
A damaged or corroded connector. Wiring faults come next, and a bad sensor or computer is less likely.

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