P0994Transmission Fluid Pressure Sensor/Switch F Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- The signal of pressure sensor or switch F stays low. No manufacturer documents this code publicly. With a normally closed switch as described by Sonnax for GM's valve body modules, low means the contacts stay closed, so the module sees no pressure where pressure should be, or the signal wire is shorted to ground. GM's equivalent for switch E, P0989, flags a low signal when commanded pressure is 50 kPa or less and handles it as Special No Trip without MIL; Saab's 9-4X text gives 0 V as the low state and 12 V as high. For an analogue sensor, low would mean a voltage below its valid range. CARB requires such out-of-range checks on transmission inputs. P0995 is the high counterpart.
- What you may notice
- Harsh or delayed shifts
- Shift adaptation frozen
- Possible limp mode
- Likely causes
- LikelySignal wire shorted to ground
- PossibleSwitch stuck closed by debris or damaged film
- RareClutch circuit not reaching pressure (valve or seal leak)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.