Powertrain, generic · Fuel and air metering (injector circuit)

P02FF Propulsion System Inactive Timer Performance

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

Many diagnostics need to know how long the engine – or, on hybrids, the whole propulsion system – has been off: thermostat and evaporative checks and the cold-start strategy, for which CARB requires at least 6 hours of standstill. A timer measures this time, and the engine module checks its plausibility, for example against coolant cooling – a GM patent describes such a check. P02FF means that timer is implausible. Mercedes documents it on M256, M260, M264 and M274 engines of around 2020: after an internal reset the instrument cluster clock ran wrong; the fix is a software update for engine, transmission and instrument cluster modules. Readiness of standstill-dependent monitors may stay incomplete.

Likely causes

Time source in another module (instrument cluster, body module) gives an implausible time after a reset or voltage loss
Software level of engine, transmission or instrument cluster module
Battery discharged or disconnected, voltage dips
Instrument cluster or timer in the engine module faulty
Coolant temperature sensor distorting the cooling check

Symptoms

  • Check engine light on, otherwise usually nothing noticeable
  • Clock in the instrument cluster wrong or reset
  • Readiness of standstill-dependent monitors incomplete

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–900
Time0.3–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

engine control moduleinstrument clusterengine off timer

Related codes

P2610P0603P0128P0116U0155

References: static.nhtsa.gov, law.cornell.edu, patents.google.com, newtonnet.co.uk.