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P0993 – Transmission Fluid Pressure Sensor/Switch F Circuit Range/Performance (OBD2)

P0993 means "Transmission Fluid Pressure Sensor/Switch F Circuit Range/Performance". The transmission fluid pressure sensor/switch signal is electrically present but implausible: it does not match what the control unit expects for the current operating conditions or from other sensors. This is a performance fault, not a broken wire.

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P0993 quick summary

Fault codeP0993
MeaningTransmission Fluid Pressure Sensor/Switch F Circuit Range/Performance
SystemPowertrain (Engine & Transmission)
VehiclesGeneric OBD2
SeverityHigh
Can I drive?Carefully and only to a workshop. Low hydraulic pressure can cause slipping and damage.
Repair cost€50 – €2,500

How gearbox pressure sensors and switches work

Transmission pressure sensors and switches confirm that hydraulic pressure is present in each circuit; these codes cover their signals, low or high fluid pressure and deteriorated fluid.

Many automatic and dual-clutch gearboxes have pressure switches or sensors (A–F) that report whether pressure has reached a clutch circuit. The control unit uses them to confirm shifts and to detect slipping or hydraulic faults.

Codes P0840–P0849, P0870–P0879 and P0987–P0996 report circuit, range, low, high and intermittent faults; P0867–P0869 report fluid pressure that is too low or too high; P0897 means the control unit has calculated that the fluid has deteriorated.

Low pressure can be caused by low fluid level, a clogged filter, a weak pump or internal leaks; sensor faults by internal harness problems.

On VAG vehicles (VW, Audi, Škoda, Seat, Cupra), VCDS and older VAG testers can show this code as the five-digit VAG code 17377 (P0993). Both numbers mean the same fault.

Symptoms of P0993

  • Harsh, slipping or delayed shifts
  • Limp mode
  • Gearbox warning light
  • No drive or delayed engagement
  • Fluid service reminder (deteriorated fluid)

Most common causes of P0993 (most likely first)

Mechanic's Pro Tip

For P0897 (fluid deteriorated), a fluid change alone is not enough on many cars – the fluid ageing counter must also be reset with a scan tool, or the code will return.

  1. 1.Transmission fluid pressure sensor/switch worn, contaminated or out of calibration

    Most likely

    The signal drifts slowly, so it is still within the electrical limits but wrong.

  2. 2.Mechanical problem in the system the transmission fluid pressure sensor/switch measures or controls

    For example a leak, a sticking part or a restriction that really changes the measured value.

  3. 3.High resistance in a connector or ground

    Corrosion causes a voltage drop that shifts the reading.

  4. 4.Low fluid level or clogged filter

  5. 5.Faulty pressure sensor or switch

  6. 6.Weak oil pump or internal leak

  7. 7.Old, degraded fluid

Step-by-step diagnostic guide

  1. 1

    Read codes and pressure values

    Read the transmission codes and pressure values in live data.

  2. 2

    Compare live data with expected values

    Read the transmission fluid pressure sensor/switch values in live data and compare them with related readings (engine speed, load, temperature or pressure) and with the specification. A value that is electrically fine but wrong for the conditions confirms a performance fault – then check the mechanical side before replacing the part.

  3. 3

    Check fluid level and condition

    Check fluid using the manufacturer's procedure and temperature.

  4. 4

    Check the sensor circuit

    Measure the sensor supply, ground and signal or switch state.

  5. 5

    Measure line pressure

    Measure real pressure with a gauge where possible.

    Multimeter: Compare with the specification for the gear and engine speed.

  6. 6

    Repair and adapt

    Replace the sensor, filter or fluid, or repair the hydraulic fault, then run adaptations.

Frequently asked questions

Can I keep driving with P0993?

Carefully and only to a workshop. Low hydraulic pressure can cause slipping and damage.

How much does it cost to fix P0993?

Typical repair costs are 50 € – 2500 €, depending on the cause and the vehicle. The most common fixes are: transmission fluid pressure sensor/switch worn, contaminated or out of calibration; mechanical problem in the system the transmission fluid pressure sensor/switch measures or controls; high resistance in a connector or ground. Always confirm the cause with the tests above before buying parts.

What does 'transmission fluid deteriorated' mean?

The control unit has calculated, from temperature and time, that the fluid is worn out and should be changed.

Can a pressure sensor cause limp mode?

Yes. Without a reliable pressure signal, the gearbox may switch to a safe mode.

What is the difference between P0993 and similar codes?

P0993 belongs to a group of codes for the same component that differ in the type or location of the fault: P0990 – Transmission Fluid Pressure Sensor/Switch E Circuit High; P0991 – Transmission Fluid Pressure Sensor/Switch E Circuit Intermittent; P0992 – Transmission Fluid Pressure Sensor/Switch F Circuit; P0994 – Transmission Fluid Pressure Sensor/Switch F Circuit Low; P0995 – Transmission Fluid Pressure Sensor/Switch F Circuit High; P0996 – Transmission Fluid Pressure Sensor/Switch F Circuit Intermittent. The tests on this page apply to the whole group; the type of fault tells you where to start.

Related fault codes

This guide is for information only. Working on vehicles can be dangerous — if you are unsure, have the car checked by a qualified mechanic. Values can differ between model years; always check the manufacturer's repair information.