Powertrain, generic (extended)

P2A32 AFCM Power Relay Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Gas installations that carry a separate control unit for the gas side, the AFCM, may feed that unit through a relay whose coil is switched by a driver stage. P2A32 means this coil circuit shows no current path: the driver output sees an open line, a missing plug or a burnt coil. Ford's 2003 bi-fuel CNG pickups show how such a module manages relays itself; it energises the ALT fuel relay feeding the tank and rail solenoids. No manufacturer publishes P2A32 itself, so the logic is inferred from the engine-module counterpart P0685: on Saab's 2010 V6, GM Europe compares commanded and actual driver state and reports a mismatch lasting 4 s, or 30 s in total. If the relay never pulls in, the gas side stays dead and a bi-fuel vehicle keeps running on petrol.

Likely causes

Broken control wire or unplugged relay socket
Relay coil burnt out
Blown fuse in the coil feed of the relay
Output driver in the controlling module faulty

Symptoms

  • Check engine light, depending on calibration
  • Gas mode cannot be selected, vehicle stays on petrol
  • Dedicated gas engine: no start

Repair estimate

DifficultyMediumDIY possible
Parts and labour€20–400
Time0.5–2 h

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

Parts involved

afcm power relayafcmwiring harness

Related codes

P2A33P2A34P2A35P0685U0108

References: law.cornell.edu, static.nhtsa.gov, saabwisonline.com.