P24EC
NH3 Sensor Supply Voltage Circuit High
What it means
The NH3 slip sensor supply voltage rises above the upper limit. Either the supply is shorted to battery voltage or an internal regulator in the dosing module has failed open. The sensor electronics may be damaged if the condition persists, so the ECM disables the input.
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
Supply line shorted to battery voltage
highOne of the most commonly reported causes for this code — check this first.
Failed voltage regulator in the dosing module
mediumA plausible cause — test and verify before replacing parts.
Connector pins corroded - high contact resistance
lowLess common, but worth ruling out after the more likely causes.
Related help
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