P24EB
NH3 Sensor Supply Voltage Circuit Low
The NH3 slip sensor supply voltage drops below the lower limit. Usually a partial short to ground in the supply line, an undersized ground path with high resistance, or an internal supply collapse in the SCR/dosing module. Sensor output is held invalid until the supply recovers.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Supply line shorted to groundCommon
- High-resistance ground at the SCR modulePossible
- Connector pins corroded - high contact resistanceLess likely
Parts involved
- Nh3 Sensor
- Supply Wiring
- Dosing Module
P24EB is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.