Chassis, generic

C0912 TPMS Initiator Front Circuit Malfunction

Check engine lightUsually off
EmissionsNot relevant
Drive cycleRequired
Limp modeNo

C0912 could not be found in any code list, bulletin or service index, so its use remains unproven. The title refers to the front initiator: a coil near the wheel that wakes the tire sensor with a low frequency field so the system can tell which corner answered. A TRW patent mounts one such induction coil per wheel well and sends at about 125 kHz, relying on the field fading quickly with distance so only the adjacent sensor reacts. A Ford patent wires each initiator straight to the controller and raises the drive current step by step until the sensor replies. Honda reports a shorted initiator line as code 45. An open or shorted front circuit leaves the front sensors unlocated, so pressure values may lack their position.

Likely causes

Initiator wiring in the wheel arch chafed, corroded or unplugged
Initiator coil open or shorted internally
Initiator knocked out of its mount by wheel arch liner damage
Output stage in the TPMS module defective

Symptoms

  • TPMS malfunction lamp on
  • Front tire pressures shown without wheel position or not at all after a tire change

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–300
Time0.5–2 h

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

Parts involved

tpms initiatortpms moduleinitiator wiring

Related codes

C0901C0903C0910

References: patents.google.com, patents.google.com, ateq-tpms.com.