P0934
Hydraulic Pressure Sensor Circuit Low
Transmission hydraulics
Generic OBD-II
Medium
What it means
P0934 means the transmission's hydraulic pressure sensor is sending a signal that's too low — often a short to ground, an open, or a failed sensor rather than an actual pressure problem. The engine starts and runs normally, but because the controller can't trust the pressure reading, shift quality can suffer and the transmission may enter a protective mode. Check the wiring and fluid level, then the sensor itself.
Medium
Can I keep driving? Usually drivable, but shifts may feel rough or lazy — get it checked soon to protect the transmission.
Common symptoms
What you'll notice
- Check-engine light on
- Rough, harsh, or delayed shifting
- Transmission may enter a fail-safe (limp) mode
- Slightly reduced fuel efficiency
Common causes
Most likely first
- Faulty hydraulic pressure sensorLikely
- Short to ground or open in the sensor signal circuitCommon
- Loose or corroded connector at the sensorCommon
- Low or dirty transmission fluid affecting real pressureLess often
- Failed transmission control module (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm the sensor is reading low (near zero).
- Check transmission fluid level and condition.
- Inspect the hydraulic pressure sensor connector and wiring for a short to ground or open.
- Measure the sensor's reference and signal voltages against spec.
- Replace the pressure sensor if it reads low, repair wiring as needed, then clear and road-test.
FAQ
Quick answers
Is it safe to drive with P0934?+
Short trips are usually okay, but rough or slipping shifts stress the transmission. Have it diagnosed before long drives.
Can I just clear P0934?+
It returns until the sensor or wiring is repaired. A low reading is often a wiring short or a failed sensor rather than a real pressure loss.
Related codes
Often seen with P0934
Read & clear P0934 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX