P0604 fault code: what it means

P0604: Engine computer self-check (RAM) fault.

Engine and gearbox (powertrain) · Costly if missed

Usual causes, most likely first

DME internal fault
low voltage or bad grounds

P0604 by make

BMW

Engine computer self-check (RAM) fault.

Usual causes: DME internal fault; low voltage or bad grounds

Mini

Engine computer self-check (RAM) fault.

Usual causes: DME internal fault; low voltage or bad grounds

Subaru

ECM RAM error. Engine may not start or may stall.

Usual causes: ECM internal fault; low voltage event

Volvo

Engine computer RAM error.

Usual causes: engine computer internal fault; power or ground fault

What the repair usually costs

Alternator replace (small / medium car, petrol)NZ$510–NZ$1,020 · A$480–A$1,000
Alternator replace (SUV / ute / diesel)NZ$750–NZ$1,560 · A$710–A$1,490
Alternator replace (European, smart charging)NZ$930–NZ$2,130 · A$850–A$1,990

Not sure what P0604 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.