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

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.

Likely causes

Symptoms

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

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: law.cornell.edu, gsi.ext.gm.com, sonnax.com.