Powertrain, generic (extended)

P2E61 Alternative Fuel Misfire Detected With Low Fuel

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P2E61 records misfire that occurs while the engine burns its gaseous fuel and that fuel is almost used up. No manufacturer documents the code publicly. CARB treats a bi-fuel car as alternate-fueled only while it runs on gas and lets makers seek approval to suspend misfire monitoring at 15 % fuel or less, since a nearly empty tank can cause misfire by itself. Ford patents explain it for CNG: the regulator keeps the rail at a few bar, but near 500 psi tank pressure the flow chokes and rail pressure wavers, so metering suffers; one known answer is switching to petrol at low tank pressure. Another Ford patent reads low rail pressure despite gas in the tank, e.g. from ice, as a supply restriction. Refill and recheck; misfire with ample gas is P2E58 to P2E60.

Likely causes

Gas tank close to empty, so the regulator can no longer hold rail pressure
Tank pressure or level signal reads too high, so the system stays on gas too long
Restriction in the gas line (clogged filter, ice) that only shows when tank pressure is low
Worn plugs or coils that cannot ignite the leaner gas mixture near empty

Symptoms

  • Stumbling or power loss on gas when the gas gauge is near empty
  • Vehicle changes over to petrol on its own
  • Check engine light on

Repair estimate

DifficultyEasyDIY possible
Parts and labour€0–400
Time0.2–2 h

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

Parts involved

alt fuel injectorsalt fuel railignition coils

Related codes

P2E58P2E59P0300P0460P0171

References: law.cornell.edu, image-ppubs.uspto.gov, image-ppubs.uspto.gov.