P21E7 code meaning
Cylinder 6 Injector B Circuit High
Powertrain system Generic code P21xx codes Check engine light
What P21E7 means
P21E7 is stored when the B injector of cylinder 6 shows a short toward power. GM's 2019 Corvette ZR1 with the LT5 V8 is the documented user; there the FICM checks the low side only in the driver-off state, flags 0.5 Ohm or less to power, and needs at least 11 V at the powertrain relay with the engine running. The result is a Type A fault after one trip. With the low side tied to supply, every switching attempt would push current straight into the driver, so the injector on the right-bank cylinder 6 delivers nothing. A useful check is to unplug the injector: if the voltage on the control wire stays, the harness is at fault; if it disappears, the injector coil is suspect. P21E6 is the matching low fault and P0277 the A injector high code.
P21E7 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 P21E7
- Check engine light on
- Lean condition on bank 2 under load
- Cylinder 6 misfire at high load
Common causes of P21E7
- Most likelyCylinder 6 B injector control wire in contact with a live wire
- PossibleShorted turns in the injector coil
- Less likelyOutput stage of the injection control module damaged by the short
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 P21E7 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. |
| E7 | The exact fault in that area. |
What to do next
- Note P21E7 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 P21E7
What does P21E7 mean?
P21E7 means "Cylinder 6 Injector B Circuit High". P21E7 is stored when the B injector of cylinder 6 shows a short toward power. It is a generic code, so it means the same on every make.
Is it safe to drive with P21E7?
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 P21E7 fail an emissions test?
Yes, it can. P21E7 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 P21E7 to fix?
Difficulty: hard. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P21E7 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.