P12A1 fault code: what it means

P12A1: Fuel rail pressure reading too low (direct injection). Hesitation, power loss or long cranking.

Engine and gearbox (powertrain) · Costly if missed

Usual causes, most likely first

weak high-pressure fuel pump
faulty rail pressure sensor
low-pressure supply fault

P12A1 by make

Porsche

Fuel rail pressure reading too low (direct injection). Hesitation, power loss or long cranking.

Usual causes: weak high-pressure fuel pump; faulty rail pressure sensor; low-pressure supply fault

What the repair usually costs

CVT valve body replacement (remanufactured, in car)NZ$1,280–NZ$2,420 · A$1,200–A$2,400
Direct-injection petrol injectors (set)NZ$1,490–NZ$3,850 · A$1,350–A$3,520
High-pressure fuel pump (GDI petrol or common-rail diesel)NZ$1,140–NZ$4,280 · A$1,060–A$3,800
Intake valve carbon clean (walnut blast, direct injection)NZ$530–NZ$1,190 · A$560–A$1,240

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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.