P0993: Transmission Fluid Pressure Sensor/Switch F Circuit Range/Performance

What does P0993 mean?

Pressure sensor or switch F is electrically intact, but its reading does not match what the module expects from the commanded clutch state. No manufacturer documents this code publicly. The closest documented logic is GM's for switch E (TFP switch 5, 6T70/6T75): the module checks after each clutch release whether the switch returns to its exhausted state and counts failures, at 50 kPa or less commanded pressure for the low case. A sixth switch would be checked the same way, plausibility against commanded pressure and gear, which CARB requires for transmission inputs. Typical causes are sticking regulator valves, debris and worn switch films rather than wiring. P0992 is the plain circuit fault, P0994/P0995 are low and high.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Harsh or flared shifts
• Shift adaptation frozen
• Warning light depending on calibration

Common causes

• High Sticking clutch regulator valve feeding the switch
• Medium Worn or delaminated switch film, debris in the switch
• Medium Low or contaminated transmission fluid

Likelihood is a general estimate across vehicles; your make and model may differ.