What it means
The hydraulic pressure sensor reports a circuit intermittent fault. Hydraulic system pressure feedback is unreliable.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The hydraulic pressure sensor sends pressure feedback to the TCM so it can manage transmission operation. P0936 sets when that sensor circuit's signal becomes intermittent, making the pressure feedback unreliable rather than consistently high or low.
Common causes
Most likely first.
- Pressure sensor failed
- Wiring fault
- Connector with intermittent contact under vibration
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Save freeze-frame data and monitor live pressure-sensor data while noting when the warning or shifting symptoms occur.
- Inspect the pressure sensor connector and harness for loose pins, corrosion, chafing, or damage, especially where movement or vibration could interrupt contact.
- With live data displayed, carefully move accessible sections of the harness and connector to see whether the signal drops out or jumps.
- Check the sensor signal, power or reference, and ground connections against the manufacturer's wiring information, looking for an intermittent open or high-resistance contact.
- If the wiring remains stable, test the pressure sensor and compare its feedback with an appropriate pressure check before replacing parts.
Common fixes
- Reseat or clean a loose or corroded pressure sensor connector.
- Repair a chafed or broken wire causing intermittent pressure feedback.
- Replace a pressure sensor that drops out despite a stable circuit.
- Address any confirmed hydraulic pressure problem contributing to erratic readings.
Can I keep driving?
Avoid driving if shifts are slipping, shuddering, or missing, or if the transmission is locked in one gear; unreliable pressure feedback can lead to sudden loss of drive or further transmission damage. If symptoms are mild, drive only as needed to reach a safe place for repair.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.