P0720 fault code: what it means

P0720: Transmission output speed sensor circuit fault.

Engine and gearbox (powertrain) · Costly if missed

Usual causes, most likely first

faulty output speed sensor
damaged wiring
low or dirty transmission fluid

P0720 by make

Mercedes-Benz

Gearbox output speed sensor fault. On Mercedes usually the 13-pin connector or conductor plate; limp mode.

Usual causes: leaking 13-pin gearbox connector; failed conductor plate; oil leak at connector O-ring

Mitsubishi

CVT output (secondary pulley) speed sensor circuit fault.

Usual causes: faulty output speed sensor; wiring or connector fault; metal debris on the sensor

Nissan

CVT output (secondary) speed sensor signal missing or erratic. May show with speedo or ABS-related speed codes.

Usual causes: output (secondary) speed sensor fault; sensor wiring or connector fault; sensor power supply fuse; TCM fault (rare)

What the repair usually costs

Parking sensor replace, one sensorNZ$130–NZ$520 · A$130–A$510
Valve (rocker) cover gasket (inline 4 / 6)NZ$180–NZ$560 · A$190–A$580
Valve (rocker) cover gaskets (V6 / V8, both banks)NZ$380–NZ$980 · A$390–A$1,010
Sump (oil pan) gasket resealNZ$250–NZ$770 · A$270–A$810

Not sure what P0720 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.