Powertrain, generic (extended)

P21E0 Cylinder 3 Injector B Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P21E0 reports a low circuit state on the B injector of cylinder 3. Mitsubishi lists it for the 2022 Eclipse Cross as the direct injector code and does not use the open code P21D1, so an interrupted wire and a short to ground both end up here once they last 2 s. Its procedure measures the injector across its two DI terminals at the intermediate connector, then the harness on both sides of that connector, and only then suspects the ECM. Port injector faults on the same cylinder are P0267 and P0268. On GM's 2019 LT5 V8 cylinder 3 is the second cylinder on the left bank; its supplemental injector fails this test with less than 0.5 Ohm between low side and ground in 20 of 25 samples while the driver is off, Type A in one trip. Expect a cylinder 3 misfire; P21E1 is the high fault.

Likely causes

Cylinder 3 injector wire broken or shorted to ground
Injector of cylinder 3 with open or shorted coil
Engine control module output faulty

Symptoms

  • Check engine light on
  • Misfire on cylinder 3 (P0303)
  • Rough idle

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

P21E1P21D1P0267P21DEP21E2P0303

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