What does code P2891 mean?

Q: What does code P2891 mean?

Cylinder 1 Ion Current Sense Circuit Range/Performance. P2891 indicates that the engine control module has detected an out-of-range or erratic signal from the ion current sense circuit for cylinder 1, which is used to monitor combustion quality. The computer compares the expected ion current signature against what it actually receives and sets this code when the signal falls outside the acceptable performance window.

DTC codes / P28xx · Transmission / P2891

P2891Cylinder 1 Ion Current Sense Circuit Range/Performance

P2891 indicates that the engine control module has detected an out-of-range or erratic signal from the ion current sense circuit for cylinder 1, which is used to monitor combustion quality. The computer compares the expected ion current signature against what it actually receives and sets this code when the signal falls outside the acceptable performance window.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.