Powertrain, generic (extended)

P21EB Cylinder 8 Injector B Circuit High

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modeNo

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.

Likely causes

Cylinder 8 B injector control wire shorted to a feed wire

Shared harness connector shorted when several injectors are affected

Injector coil shorted

Injection control module damaged

Symptoms

Check engine light on
Lean bank 2 under boost
Normal behaviour at part load

Repair estimate

DifficultyHardWorkshop job

Parts and labour€100–900

Time1–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel injectorinjector wiringengine control module

References: gsi.ext.gm.com, lsxmag.com.