Skip to content
Book on WhatsApp

P269B

Exhaust Aftertreatment Glow Plug Control Circuit / Open

The control line for the aftertreatment glow plug (used on some diesels to ignite injected HC during DPF regeneration) is open. Active regeneration cannot start.

  • Check engine light: Yes
  • Emissions related: No
  • Repair difficulty: medium

Symptoms

  • Glow plug warning light on (often orange coil symbol)
  • Hard cold start or no start in cold weather
  • White smoke from exhaust during warm-up

Common causes

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

  • Open coil in glow plug control relayCommon
  • Broken control wirePossible

Parts involved

  • Aftertreatment Glow Plug
  • Control Module
  • Wiring Harness

P269B 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.