Hydraulic Oil Temperature Sensor Circuit
The engine computer detects a problem with the hydraulic oil temperature sensor circuit, which monitors fluid heat in automatic transmissions. It's like a thermometer that's either broken, disconnected, or sending false readings to the transmission control module.
The ECU monitors voltage output from the hydraulic oil temperature sensor to track fluid temperature and optimize shift timing and pressure. The sensor typically uses a thermistor that changes resistance with temperature. If voltage is out of range, too high, too low, or unstable, the ECU triggers P0937.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Sensor Voltage | 0.5–4.5V (proportional to 40–120°C) | <0.1V or >4.9V for extended duration |
| Oil Temperature Rate of Change | Gradual, realistic changes | Implausible spikes or no change over time |
Code P0937 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P0937 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.