P25FD: Turbocharger/Supercharger Bypass Valve C Temperature Too High

This code says bypass valve C has become too hot. Recirculation valves are placed in the charge air path close to the compressor and thus near the hot turbine side, and an electric valve's coil adds its own heat when energised for long periods. How the engine module learns the temperature – a sensor in the valve or an estimate from current and duty cycle – is not stated in any public manufacturer document, and none documents P25FD itself. To protect the coil the module will usually limit or stop driving the valve, which can then lead to surging on lift-off or reduced boost. Separate codes cover the same overheating for valves A and B (P00D7, P00D8); a valve that is jammed rather than overheated is P25FC.

Symptoms

• Check engine lamp on
• Fluttering on lift-off or reduced boost after hard driving

Most likely causes

• Heat soak from the turbocharger, e.g. after hard driving or with missing heat shields
• Valve coil drawing too much current due to an internal fault
• Sluggish valve held energised longer than intended

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the hoses, clamps, and intercooler
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Compare commanded and actual pressure in live data
4. Check the actuator's movement
5. Check the vacuum hoses and the solenoid valve
6. Check the oil and the turbo shaft play before replacing it

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P25FD means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 5: Speed and idle
• FD: Specific fault in that system

Frequently asked questions

Can I keep driving with code P25FD?

Drive without demanding power and go to a repair shop soon. If you see a lot of blue smoke or hear a metallic noise, shut off the engine.

What causes code P25FD?

The most common causes are: heat soak from the turbocharger, e.g. after hard driving or with missing heat shields; valve coil drawing too much current due to an internal fault; sluggish valve held energised longer than intended.

Related codes

• P25FCTurbocharger/Supercharger Bypass Valve C - Mechanical
• P25F8Turbocharger/Supercharger Bypass Valve C Control Circuit
• P00D7Turbocharger/Supercharger Bypass Valve A Temperature Too High
• P00D8Turbocharger/Supercharger Bypass Valve B Temperature Too High
• P2BC0Turbocharger/Supercharger Bypass Valve A Driver Current/Temperature Too High

Sources

• law.cornell.edu: 13 CCR 1968.2
• ms-motorservice.com: electric recirculating air valves
• en.wikipedia.org: Blowoff valve

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.