P21EA code meaning
Cylinder 8 Injector B Circuit Low
Powertrain system Generic code P21xx codes Check engine light
What P21EA means
P21EA is the ground-short code for the B injector of cylinder 8 and the last low code in GM's 2019 FICM table for the Corvette ZR1 LT5, because the V8 ends there. Cylinder 8 is the rearmost of the right bank (bank 2). The module flags 0.5 Ohm or less between the switched-off low side and ground in 20 of 25 samples of 100 ms, with the engine running and 11 V or more at the powertrain relay, as a Type A fault. Mitsubishi's four-cylinder dual-injection engine never reaches this code, and Ford treats a B-injector short on cylinder 8 as P21D6. A grounded low side can hold the injector open, so bank 2 runs rich and fuel can wash the cylinder wall. P21EB is the high fault; the A injector low fault is P0282.
P21EA at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor1 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P21EA
- Check engine light on
- Rich running on bank 2
- Hard hot start or misfire on cylinder 8
Common causes of P21EA
- Most likelyCylinder 8 B injector wiring chafed through to ground
- PossibleWater or corrosion in the cylinder 8 injector plug
- PossibleInjector shorted to its body
- Less likelyFICM driver stuck on
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 P21EA 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. |
| EA | The exact fault in that area. |
What to do next
- Note P21EA 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 P21EA
What does P21EA mean?
P21EA means "Cylinder 8 Injector B Circuit Low". P21EA is the ground-short code for the B injector of cylinder 8 and the last low code in GM's 2019 FICM table for the Corvette ZR1 LT5, because the V8 ends there. It is a generic code, so it means the same on every make.
Is it safe to drive with P21EA?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P21EA fail an emissions test?
Yes, it can. P21EA 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 P21EA to fix?
Difficulty: hard. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P21EA clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.