Powertrain, generic (extended)

P21E1 Cylinder 3 Injector B Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P21E1 is the high fault on the cylinder 3 B injector circuit. In Mitsubishi's 2022 Eclipse Cross that is the direct high-pressure injector, and the module reacts to a short circuit lasting 2 s, checked with 10 to 16.5 V battery voltage. To confirm a repair, the manual points to its OBD drive cycle pattern 1. GM's 2019 LT5 V8 monitors the low side of the supplemental cylinder 3 injector in its separate FICM module and flags under 0.5 Ohm toward power as Type A with the MIL in the first trip. A short to power keeps the low side from ever reaching ground, so the injector cannot open, and switching against the short can strain the driver stage. P21E0 covers the low fault and P0268 the port injector high fault on Mitsubishi; a cylinder 3 misfire often follows.

Likely causes

Cylinder 3 injector line shorted to supply voltage
Shorted injector coil
Damaged driver in the control module

Symptoms

  • Check engine light on
  • Cylinder 3 not firing properly
  • Torque reduction if several injectors fail (Mitsubishi)

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

P21E0P21D1P0268P21DFP21E3P0303

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