Powertrain, generic · Ignition system or misfire

P0314 Single Cylinder Misfire (Cylinder Not Specified)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0314 means the misfire is attributable to a single cylinder, but the module does not say which one. CARB generally requires cylinder-specific codes and allows a general code only with approval where the cylinder cannot be identified reliably; for diesels identification is required only where possible without extra hardware. GM and Ford do not use P0314. It is documented on Saab's 2.2 TiD diesel with a Bosch distributor pump, as a mechanical misfire fault in two speed and quantity windows with the warning light and limp mode limiting injection quantity; the cylinder can still be read out with a scan tool. Typical causes are a faulty injector, leaking high-pressure lines, air or water in the fuel, or low compression.

Likely causes

Injector of one cylinder clogged or leaking (diesel), or coil/plug (petrol)
Leaking high-pressure line, fuel bridge or injector washer
Air, water or petrol in the diesel, clogged filter, low supply pressure
Compression loss (valve, piston)

Symptoms

  • Check engine light on
  • Loss of power, limp mode with quantity limit (Saab diesel)
  • Rough running, vibration

Repair estimate

DifficultyHardWorkshop job
Parts and labour€80–1,500
Time1–6 h

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

Parts involved

fuel injectorshigh pressure linesignition system

Related codes

P0300P0301P0263P0201P0087

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