P21E0 code meaning
Cylinder 3 Injector B Circuit Low
Powertrain system Generic code P21xx codes Check engine light
What P21E0 means
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.
P21E0 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyHard
- Typical labor1 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P21E0
- Check engine light on
- Misfire on cylinder 3 (P0303)
- Rough idle
Common causes of P21E0
- Most likelyCylinder 3 injector wire broken or shorted to ground
- PossibleInjector of cylinder 3 with open or shorted coil
- Less likelyEngine control module output faulty
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel injectorInjector wiringEngine control module
What each part of P21E0 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 1 | Area: fuel and air metering. |
| E0 | The exact fault in that area. |
What to do next
- Note P21E0 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P21E0
What does P21E0 mean?
P21E0 means "Cylinder 3 Injector B Circuit Low". P21E0 reports a low circuit state on the B injector of cylinder 3. It is a generic code, so it means the same on every make.
Is it safe to drive with P21E0?
Drive gently and only to a workshop. With P21E0 the car can go into limp mode (reduced power) to protect itself.
Will P21E0 fail an emissions test?
Yes, it can. P21E0 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P21E0 to fix?
Difficulty: hard. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P21E0 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.