Powertrain, generic (extended)

P21E6 Cylinder 6 Injector B Circuit Low

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modeNo

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.

Likely causes

Cylinder 6 B injector harness chafed against engine metal

Internal short to ground inside the injector

Injection control module output stuck low

Symptoms

Check engine light on
Rich condition on bank 2, possibly fuel smell
Fouled spark plug or misfire on cylinder 6

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, law.cornell.edu.