Powertrain, generic (extended)

P26A1 Exhaust Aftertreatment Glow Plug Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P26A1 describes a load circuit of the exhaust glow plug that reads too low: the feed or the element has found a path to ground, so the current bypasses the heater or exceeds what the circuit allows. Shorted elements, insulation damage at the hot plug body and wiring melted against the exhaust are the expected causes; a fuse in the glow plug feed may blow repeatedly. No manufacturer documents this code publicly. Ford's 3.2 L Transit, which uses the neighboring codes for its vaporizer glow plug, files a grounded control line under P269D instead. CARB's output component rules call for detection of such circuit faults on emission-related heaters. The vaporizer cannot heat, so exhaust dosing and filter regeneration are restricted.

Likely causes

Glow element shorted to its housing
Feed wire melted or chafed against the exhaust
Fuse blown as a result of the short

Symptoms

  • MIL on
  • Fuse for the glow plug circuit blows again after replacement
  • Regeneration blocked

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–450
Time0.5–2 h

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

Parts involved

aftertreatment glow plugsupply circuit

Related codes

P269FP26A0P26A2P269D

References: law.cornell.edu, fordservicecontent.com.