Credov

P1477 fault code: what it means

P1477: Leak diagnosis pump reed switch did not open. The DMTL pump is sticking.

Engine and gearbox (powertrain) · Minor

Usual causes, most likely first

  1. sticking DMTL pump
  2. water or dirt in the DMTL

P1477 by make

BMW

Leak diagnosis pump reed switch did not open. The DMTL pump is sticking.

Usual causes: sticking DMTL pump; water or dirt in the DMTL

Not sure what P1477 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.