P0291 Cylinder 11 Injector Circuit Low

P0291 points to a low injector circuit on cylinder 11. The injector 11 control path is grounded, missing voltage, or below expected current.

Code status

Needs verification

Not yet verified against SAE J2012_202509 / J2012DA. Treat unverified rows as a lookup aid, not repair authority.

System: Injector
Scope: iso-sae-controlled-p0
Standard: SAE J2012 / ISO 15031-6
Source: legacy-import

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not replace injector 11 before confirming the low circuit path through power feed, wiring, and driver output.

Useful checks before replacing parts

Measure cylinder 11 injector feed, control voltage, resistance, and current while checking for short-to-ground conditions.
Compare cylinder 11 misfire counters, balance, injector pulse, contribution data, and freeze-frame load conditions.
Inspect injector 11 connector terminals, harness routing, shared feed circuits, oil intrusion, moisture, and rubbed insulation.

Related OBD-II codes

These nearby injector entries can help compare wording and fault area. They may share the same verification status as the source database.