P0873
Transmission Fluid Pressure Sensor/Switch C Circuit High
Transmission fluid pressure sensing
Generic OBD-II
Medium
What it means
P0873 means the transmission fluid pressure sensor on circuit "C" is reporting a signal higher than the normal operating range, usually from a wiring short-to-power or a failed sensor. The engine runs fine, but the transmission depends on accurate pressure data to shift cleanly, so you may see harsh or missing shifts and, in some cases, a protective limp mode until it's corrected.
Medium
Can I keep driving? The engine starts and runs; the car is drivable, but shifting may be harsh or the transmission may limp into one gear — fix soon to avoid clutch and band wear.
Common symptoms
What you'll notice
- Check-engine light on
- Harsh or erratic shifting
- Transmission may fail to shift or enter limp mode
- Reduced power while in limp mode
Common causes
Most likely first
- Faulty transmission fluid pressure sensor/switch (circuit C)Likely
- Wiring shorted to voltage or open in the circuit (drives the signal high)Common
- Loose or corroded connectorsCommon
- Low or dirty transmission fluidLess often
- Failed transmission control module (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check transmission fluid level and condition.
- Inspect the sensor connector and wiring for shorts to power, opens, or corrosion.
- Measure the sensor signal voltage against specification.
- Replace the pressure sensor/switch if it reads out of range.
- Repair the wiring or, if needed, diagnose the TCM. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0873?+
For short trips usually, but harsh shifting or limp mode strains the transmission, so drive gently and get it repaired soon.
Can I just clear P0873?+
It clears, but a high-reading sensor or wiring fault brings it back until repaired.
Related codes
Often seen with P0873
Read & clear P0873 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