Powertrain, generic (extended)

P2A94 Alternative Fuel Tank Select Valve A Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2A94 reports a control voltage at tank select valve A above what the module expects for the commanded state. On a valve switched to ground by the module, an open coil or broken lead leaves the line floating at supply voltage; alternatively a chafed wire contacts a battery feed that the output stage cannot pull down. Either way, valve A does not respond to commands and stays wherever its spring or the foreign voltage holds it. In the staged two-supply strategy patented by Cespira, the controller then cannot move to the second supply when the first falls below its threshold, or cannot leave it. Range shrinks or the engine falls back to its other fuel. No maker publishes P2A94. Check coil resistance, then the harness to the valve.

Likely causes

Open coil or broken lead on a ground-switched valve A
Control wire of valve A touching a battery feed
Corroded pins with high resistance at valve A

Symptoms

  • Malfunction lamp on
  • No change to the next tank, gas runs out early
  • Engine switches to its other fuel or reduced power

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–1,200
Time1–4 h

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

Parts involved

alt fuel tank select valve awiring harnessafcm

Related codes

P2A91P2A92P2A93P2A98P2A9C

References: law.cornell.edu, patents.google.com.