P0E9ADC/DC Converter Voltage Sensor C Circuit Intermittent/Erratic
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P0E9A completes the sensor C voltage series of a DC/DC converter. It is meant for a signal that jumps, flickers or drops out for brief moments, which the low and high tests miss because they need a fault to persist. No manufacturer documents P0E9A publicly. The GM tables for channels A and B (25OBDG03A) illustrate the gap: their limit checks sample every 12.5 ms and require 320 failures in a window of 400, roughly four seconds, before a code is stored. Under CARB rules inputs need circuit and range tests and, if possible, a check for implausible values; an erratic code covers the cases in between. Corroded pins, a solder joint with a hairline crack or a wire that rubs through under engine movement are the usual causes, so the warning may come and go.
- What you may notice
- Warning lamp that appears and disappears
- Short interruptions of start-stop or 12 V support
- Code often stored as history only
- Likely causes
- LikelyLoose or corroded terminal in the sensor C path
- PossibleHarness chafing intermittently at a moving point
- RareCracked solder joint in the converter's measuring circuit
- 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: €50 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.