P21E8Cylinder 7 Injector B Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P21E8 covers a low, ground-side fault on the cylinder 7 B injector. GM lists it for the 2019 Corvette ZR1, where the LT5 V8 carries a direct and a supplemental injector per cylinder and cylinder 7 is the rearmost cylinder of the left bank (bank 1). The supplemental injectors have their own control module, the FICM, and that module stores the code: below 0.5 Ohm between low side and ground while its driver is off, 20 failures in 25 samples, continuous monitoring, Type A with the MIL in the first trip. Since the limit is close to a dead short, a slowly corroding connector usually shows up as a misfire before it trips this code. Expect rich running on bank 1. The neighbours are P21E9 (high) and, for the A injector, P0279; an open circuit on other makes appears as P21D5.
- What you may notice
- Check engine light on
- Rich mixture reported for bank 1
- Misfire on cylinder 7
- Likely causes
- LikelyCylinder 7 B injector wire grounded at the rear of the engine
- PossibleInjector coil leaking to ground
- RareFICM output faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.