Audi
Boost pressure is above what the engine asked for (overboost). Limp mode, usually on TDIs.
P1557 fault code: what it means
P1557: Boost pressure is above what the engine asked for (overboost). Limp mode, usually on TDIs.
Usual causes, most likely first
- sticking turbo vanes
- faulty boost control valve (N75)
- vacuum hose fault
P1557 by make
Skoda
Boost pressure is above what the engine asked for (overboost). Limp mode, usually on TDIs.
Volkswagen
Boost pressure is above what the engine asked for (overboost). Limp mode, usually on TDIs.
What the repair usually costs
- Automatic transmission rebuild, 6-speed and up (sent to specialist)NZ$7,190–NZ$13,080 · A$6,190–A$11,830
- DSG / dual-clutch mechatronic unit replacement (new or reman)NZ$4,300–NZ$7,160 · A$3,750–A$6,390
- DSG mechatronic repair / rebuild (unit sent to specialist)NZ$2,070–NZ$4,800 · A$1,890–A$4,250
- A/C compressor replace incl. drier and flush (European)NZ$1,560–NZ$3,200 · A$1,490–A$3,050
Not sure what P1557 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.