Powertrain, generic (extended)

P2311 Ignition Coil D Secondary Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P2311 concerns the secondary side of coil D, usually cylinder 4. The secondary winding has thousands of turns of fine wire and delivers roughly 15–40 kV, so insulation that is merely tired can let the spark escape to ground instead of crossing the plug gap. Few control units watch this side as a circuit of its own; FCA's 3.6 Pentastar V6 does, naming P2311 coil 4 secondary circuit with insufficient ionization in bulletin 18-069-16 (2015–2016 Caravan and Town & Country, fixed by a new PCM). Most other makers leave such faults to misfire detection, so P0304 is the more frequent companion. Because misfire can overheat the catalyst, CARB lets misfire be evaluated in blocks of 200 revolutions and demands a flashing MIL at damaging rates.

Likely causes

Aged insulation in coil D or its boot letting the spark leak to ground
Spark plug of cylinder 4 worn, gap grown
Oil in the plug well softening the boot
PCM ion-sense fault (FCA bulletin 18-069-16)

Symptoms

  • Check engine light on
  • Misfire on cylinder 4, worse in damp weather or under load
  • Flashing MIL at heavy misfire

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–900
Time0.3–3 h

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

Parts involved

ignition coilspark plug

Related codes

P2309P2310P2308P0304P0300

References: static.nhtsa.gov, en.wikipedia.org, law.cornell.edu.