Powertrain, generic (extended)

P2C27 Fuel Injector Group B Supply Sense Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2C27 reports that the voltage read back on the supply sense line of injector group B is too low while the module expects the group to be powered. In practice the feed never reaches the injectors – a blown fuse, a relay that does not close, a broken supply wire or a grounded feed – or only the sense wire itself is grounded. In the first case the cylinders of group B receive no fuel and misfire or stay dead; in the second the engine may run normally. No publicly accessible manufacturer source documents P2C27; CARB requires out-of-range low checks of such circuits. GM's direct-injection logic, documented for the Saab 9-5 2.0T, disables an injector once its supply voltage is wrong for more than 1 s and stores a Type B fault. The high case is P2C28.

Likely causes

Blown fuse in the injector group B supply
Injector relay not closing or burnt contacts
Supply or sense wire shorted to ground
Internally shorted injector pulling the group supply down

Symptoms

  • Check engine light
  • Misfire on several cylinders, rough idle
  • Clearly reduced power or engine will not start

Repair estimate

DifficultyMediumDIY possible
Parts and labour€20–600
Time0.3–3 h

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

Parts involved

fuel injector group bwiring harnessecm

Related codes

P2C26P2C28P2150P2149P0300

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