Powertrain, generic (extended)

P2A25 Alternative Fuel Tank Shutoff Valve B Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2A25 reports a voltage on the control circuit of tank valve B that is higher than the module expects, mostly because the wire touches a battery feed. TransEco Energy's fault table names a short to power as the cause, turns on the MIL and lets the gas system carry on. The real risk lies elsewhere: a solenoid held by foreign voltage stays open even when the module wants the cylinder isolated, for instance after the engine stops. Ford's 2003 bi-fuel CNG documentation shows why that matters, since its module shuts the tank valve once gas pressure falls under 517 kPa. Ford's Boss 302S list names P2A25 as well. P2A24 is the low-side partner; for valve A the equivalent code is P224F.

Likely causes

Control wire of valve B touching a battery feed
Output stage for valve B in the module stuck on
Wiring mistake during conversion or repair

Symptoms

  • Check engine light
  • Tank B may stay open with the engine off

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–1,200
Time0.5–3 h

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

Parts involved

alt fuel tank shutoff valve bwiring harnessafcm

Related codes

P2A22P2A23P2A24P2A29P224F

References: http:, performanceparts.ford.com, static.nhtsa.gov, law.cornell.edu.