P0994 code meaning
Transmission Fluid Pressure Sensor/Switch F Circuit Low
Powertrain system Generic code P09xx codes Check engine light
What P0994 means
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.
P0994 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0994
- Harsh or delayed shifts
- Shift adaptation frozen
- Possible limp mode
Common causes of P0994
- Most likelySignal wire shorted to ground
- PossibleSwitch stuck closed by debris or damaged film
- Less likelyClutch circuit not reaching pressure (valve or seal leak)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Tfp sensor fWiring harnessTCM
What each part of P0994 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 9 | Area: transmission. |
| 94 | The exact fault in that area. |
What to do next
- Note P0994 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0994
What does P0994 mean?
P0994 means "Transmission Fluid Pressure Sensor/Switch F Circuit Low". The signal of pressure sensor or switch F stays low. It is a generic code, so it means the same on every make.
Is it safe to drive with P0994?
Drive gently and only to a workshop. With P0994 the car can go into limp mode (reduced power) to protect itself.
Will P0994 fail an emissions test?
Yes, it can. P0994 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0994 to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will P0994 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.