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P0797 – Pressure Control Solenoid C Stuck On (OBD2)

P0797 means "Pressure Control Solenoid C Stuck On". The pressure control solenoid stays active even when the control unit commands it off – it is mechanically stuck or hydraulically blocked in the applied position.

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P0797 quick summary

Fault codeP0797
MeaningPressure Control Solenoid C Stuck On
SystemPowertrain (Engine & Transmission)
VehiclesGeneric OBD2
SeverityHigh
Can I drive?Only carefully and preferably to a workshop. Harsh or slipping shifts can damage the gearbox.
Repair cost€100 – €2,000

How pressure control solenoids work

Pressure control solenoids set the hydraulic pressure that engages the gearbox clutches; these codes cover their electrical circuits and performance.

In an automatic gearbox, the clutches and brakes are applied by hydraulic pressure. Pressure control solenoids (often labelled A, B, C) in the valve body regulate main line pressure and the pressure for individual clutches. The control unit drives them with a variable current to make shifts smooth.

Codes P0745–P0749, P0775–P0779, P0795–P0799 and P0960–P0971 report circuit faults (open, low, high, electrical), performance or stuck off, stuck on and intermittent faults.

Wrong pressure causes harsh or slipping shifts and often limp mode. Besides solenoid failures, dirty fluid and worn valve bodies are common causes.

On VAG vehicles (VW, Audi, Škoda, Seat, Cupra), VCDS and older VAG testers can show this code as the five-digit VAG code 17181 (P0797). Both numbers mean the same fault.

Symptoms of P0797

  • Harsh or slipping shifts
  • Limp mode
  • Delayed engagement into Drive or Reverse
  • Check Engine or gearbox warning
  • Shift flare

Most common causes of P0797 (most likely first)

Mechanic's Pro Tip

On many modern gearboxes the solenoids are only sold as part of the valve body or mechatronic unit – but specialist rebuilders often offer individual solenoids or reconditioned units at a much lower price.

  1. 1.Sticking pressure control solenoid

    Most likely

    Dirt, varnish or wear stop the valve from returning.

  2. 2.Contaminated or degraded fluid

    Debris from clutch or bearing wear blocks small passages and valves.

  3. 3.Valve body problem (sticking spool valve)

  4. 4.Faulty pressure control solenoid

  5. 5.Internal harness or connector fault

  6. 6.Transmission control unit fault

Step-by-step diagnostic guide

  1. 1

    Read codes and pressure data

    Read the transmission codes and, where available, commanded and actual pressures or solenoid currents.

  2. 2

    Check fluid and command the component

    Check fluid level and condition first. Then command the pressure control solenoid on and off with a scan tool while watching the related data (pressure, slip, ratio). If it does not release, the solenoid or valve body needs cleaning or replacement.

  3. 3

    Check fluid

    Check fluid level and condition and look for debris.

  4. 4

    Measure the solenoid

    Measure the solenoid resistance through the gearbox connector.

    Multimeter: Variable force/pressure solenoids often read about 3–8 Ω; check the specification.

  5. 5

    Check line pressure

    Measure line pressure with a gauge if the gearbox has a test port.

  6. 6

    Repair and adapt

    Replace the solenoid, valve body or harness as needed, change the fluid and run the adaptations.

Frequently asked questions

Can I keep driving with P0797?

Only carefully and preferably to a workshop. Harsh or slipping shifts can damage the gearbox.

How much does it cost to fix P0797?

Typical repair costs are 100 € – 2000 €, depending on the cause and the vehicle. The most common fixes are: sticking pressure control solenoid; contaminated or degraded fluid; valve body problem (sticking spool valve). Always confirm the cause with the tests above before buying parts.

What does a pressure control solenoid do?

It regulates the hydraulic pressure that engages the clutches, so shifts are firm but smooth.

Can dirty fluid cause these codes?

Yes. Debris and degraded fluid can make the solenoids and valves stick.

What is the difference between P0797 and similar codes?

P0797 belongs to a group of codes for the same component that differ in the type or location of the fault: P0779 – Pressure Control Solenoid B Intermittent; P0795 – Pressure Control Solenoid C; P0796 – Pressure Control Solenoid C Performance or Stuck off; P0798 – Pressure Control Solenoid C Electrical; P0799 – Pressure Control Solenoid C Intermittent; P0960 – Pressure Control Solenoid A Control Circuit / Open. 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.