P1238 fault code: what it means

P1238: Turbo boost control valve fault. Boost may be low, high or surging.

Engine and gearbox (powertrain) · Costly if missed

Usual causes, most likely first

faulty boost control valve
split vacuum hose
wiring fault

P1238 by make

Volvo

Turbo boost control valve fault. Boost may be low, high or surging.

Usual causes: faulty boost control valve; split vacuum hose; wiring fault

What the repair usually costs

A/C compressor replace incl. drier and flush (European)NZ$1,560–NZ$3,200 · A$1,490–A$3,050

Not sure what P1238 means on your car? Ask Credov.

Before you clear it

Write the code down or photograph the scanner first. A code that comes straight back after clearing points to a fault that is still there. A car whose codes were cleared just before you arrived may be hiding one: the scanner's readiness monitors show "not ready" for a while after codes are cleared.

Researched by Credov from manufacturer and workshop sources. A fault code points to where a fault may be; a workshop confirms it with a diagnosis. Browse all fault codes.