P24EE
NH3 Sensor Processor Performance
What it means
The microcontroller inside the smart NH3 slip sensor reports an internal performance fault — failed self-test, watchdog reset, or out-of-range plausibility checks. The sensor cannot guarantee its output value, the ECM marks the channel invalid and disables SCR closed-loop control on this branch.
Is it safe to drive?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Internal processor or firmware fault
highOne of the most commonly reported causes for this code — check this first.
Brown-out from supply voltage dips
mediumA plausible cause — test and verify before replacing parts.
Module software outdated, reflash may resolve
lowLess common, but worth ruling out after the more likely causes.
Related help
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