P0E31DC/DC Converter Voltage Sensor A Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P0E31 is the general circuit code of voltage sensor A in a DC/DC converter, the measurement the converter or its controller uses to regulate output voltage. It is used for electrical faults that do not fit the low, high or erratic categories. P0E31 itself is not documented publicly by any manufacturer. GM's 2025 engine tables use the neighbouring codes for the same sensor in a converter that steadies the 12 V supply during engine auto-starts: P0E33 below 1 V, P0E34 above 28 V, P0E32 for implausible values. FCA names sensor A as voltage sensor 1 on the 2021 Ram 1500 eTorque. CARB wants open circuits and out-of-range signals of such inputs reported separately where feasible. With a lost voltage signal the converter tends to stop or run in a fallback mode.
- What you may notice
- Warning light and possibly 12 V battery warning
- Engine auto-stop disabled or reduced 12 V supply
- Likely causes
- LikelyVoltage measurement inside the DC/DC converter failed
- PossibleWiring or connector fault on the converter
- RarePoor ground connection of the converter
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.