P21EB code meaning
Cylinder 8 Injector B Circuit High
Powertrain system Generic code P21xx codes Check engine light
What P21EB means
P21EB is set when the cylinder 8 B injector circuit is shorted toward power. It closes GM's run of B-injector codes for the 2019 Corvette ZR1 LT5: the FICM sees the switched-off low side within 0.5 Ohm of supply in 20 of 25 samples and stores a Type A fault, lighting the MIL in the first trip. The supplemental injector of the right-rear cylinder can then no longer be opened, while the direct injector keeps working, so the car usually drives normally until high boost, where bank 2 may lean out. If several of these high codes appear together, a common feed or a shared connector is more likely than eight bad injectors. P21EA is the matching low fault, P0283 the A injector high fault and P0308 the misfire counter of this cylinder.
P21EB 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 P21EB
- Check engine light on
- Lean bank 2 under boost
- Normal behaviour at part load
Common causes of P21EB
- Most likelyCylinder 8 B injector control wire shorted to a feed wire
- PossibleShared harness connector shorted when several injectors are affected
- PossibleInjector coil shorted
- Less likelyInjection control module damaged
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 P21EB 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. |
| EB | The exact fault in that area. |
What to do next
- Note P21EB 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 P21EB
What does P21EB mean?
P21EB means "Cylinder 8 Injector B Circuit High". P21EB is set when the cylinder 8 B injector circuit is shorted toward power. It is a generic code, so it means the same on every make.
Is it safe to drive with P21EB?
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 P21EB fail an emissions test?
Yes, it can. P21EB 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 P21EB to fix?
Difficulty: hard. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P21EB clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.