Powertrain, generic (extended)

P2A58 Alternative Fuel Vaporizer B Outlet Temperature Sensor Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Here the signal of the vaporizer B outlet sensor rests at or near the reference voltage, so the module would see a deep-frozen unit. Typical reasons are an open wire, a plug that has backed out, a sensor element that has failed open or a short to a supply line. Telling a wiring fault from a real problem matters on gas engines: CA2862664C warns that coolant inside and next to an LNG heat exchanger may turn to ice during a cold start, and such a frozen vaporizer would also read very cold, though not at the electrical limit. The control unit therefore stops trusting vaporizer B, which can mean reduced gas delivery or a fall-back fuel. AC STAG calls the open case a missing sensor. No manufacturer documents P2A58.

Likely causes

Open wire or plug of the B sensor backed out
Vaporizer B sensor element open
Signal lead touching a supply line

Symptoms

  • Check engine light, depending on calibration
  • Gas delivery reduced or fall-back fuel used
  • Vaporizer B shown at an impossibly low temperature

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€100–600
Time0.5–2.5 h

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

Parts involved

alt fuel vaporizer b outlet temp sensorwiring harnessafcm

Related codes

P2A55P2A56P2A57P2A59P2A53

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