P3448Cylinder 6 Exhaust Valve Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- If cylinder 6 had its own exhaust valve actuator, P3448 would report its control line shorted to battery voltage. No manufacturer documents this code publicly. A GM patent application on cylinder deactivation switches both sides through one shared hydraulic valve and only lets the exhaust valves go first, off and back on, so it shows no separate exhaust control either; GM's production V8s likewise put both lifters on one solenoid and publish only P3444 for a short to power on cylinder 6. That test, below 0.5 ohm to power with the driver switched on and 20 of 25 samples, is the reference for how such a fault would be judged. With the actuator unusable, deactivation is blocked. P3445 to P3447 are the sibling exhaust codes.
- What you may notice
- Check engine lamp on
- No switch to reduced-cylinder operation
- Likely causes
- PossibleExhaust actuator wire touching a supply line
- PossibleShorted turns in the exhaust actuator coil of cylinder 6
- RareEngine control module output stage faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.