P21E6 code meaning
Cylinder 6 Injector B Circuit Low
Powertrain system Generic code P21xx codes Check engine light
What P21E6 means
P21E6 reports that the B injector circuit of cylinder 6 has found a path to ground. In GM's 2019 tables for the Corvette ZR1 LT5, cylinder 6 is the third position on the right bank, which GM counts as bank 2. The FICM samples the switched-off low side every 100 ms and needs 20 bad readings out of 25, so a solid fault is confirmed within about two and a half seconds; the limit is 0.5 Ohm or less toward ground, Type A. A ground on the low side completes the injector circuit whenever its feed is live, so fuel can enter cylinder 6 without a command. Typical traces are a rich bank 2, fuel-wetted spark plug on that cylinder and fuel trims at their lean limit. P21E7 is the high fault of the same injector, P0276 the low fault of the A injector.
P21E6 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 P21E6
- Check engine light on
- Rich condition on bank 2, possibly fuel smell
- Fouled spark plug or misfire on cylinder 6
Common causes of P21E6
- Most likelyCylinder 6 B injector harness chafed against engine metal
- PossibleInternal short to ground inside the injector
- Less likelyInjection control module output stuck low
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 P21E6 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. |
| E6 | The exact fault in that area. |
What to do next
- Note P21E6 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 P21E6
What does P21E6 mean?
P21E6 means "Cylinder 6 Injector B Circuit Low". P21E6 reports that the B injector circuit of cylinder 6 has found a path to ground. It is a generic code, so it means the same on every make.
Is it safe to drive with P21E6?
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 P21E6 fail an emissions test?
Yes, it can. P21E6 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 P21E6 to fix?
Difficulty: hard. A typical repair takes 1 to 4 hours of work. This is a job for a workshop.
Will P21E6 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.