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P23D4

Cylinder 1 Fuel Heater Performance

Cylinder 1 fuel heater is electrically intact yet does not deliver the expected heat - aged element or contact resistance high.

  • Check engine light: Yes
  • Emissions related: Yes
  • Repair difficulty: medium

Common causes

Ordered by how often each turns out to be the cause.

  • Heater element agedCommon

Parts involved

  • Fuel Heater Cyl 1

P23D4 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.