Powertrain, generic (extended)

P21DE Cylinder 2 Injector B Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P21DE is the low fault of the cylinder 2 B injector circuit. In Mitsubishi's 2022 Eclipse Cross manual, B means the direct injector; the code covers both a break and a grounded wire on the two DI lines of cylinder 2, held for 2 s at 10 to 16.5 V, while the port injector of the same cylinder reports P0264. Diagnosis starts with the coil resistance at the intermediate connector, which should be 1.74 to 2.04 Ohm at 20 °C. On GM's 2019 LT5 V8 cylinder 2 is the front cylinder of the right bank; there a low side shorted to ground on the supplemental injector, below 0.5 Ohm, sets a Type A fault from its separate module. GM runs this check while the driver is switched off; a grounded low side can energise the injector without a command. P21DF is the high fault, P21D0 the open.

Likely causes

Injector line of cylinder 2 touching ground
Injector coil resistance outside specification
Fault at the intermediate connector of the injector harness

Symptoms

  • Check engine light on
  • Misfire on cylinder 2 (P0302)
  • Possible fuel smell or rich running if an injector stays open

Repair estimate

DifficultyHardWorkshop job
Parts and labour€100–900
Time1–4 h

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

Parts involved

fuel injectorinjector wiringengine control module

Related codes

P21DFP21D0P0264P21DBP21E0P0302

References: mitsubishitechinfo.com, gsi.ext.gm.com, mitsubishitechinfo.com.