P3464Cylinder 8 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
- P3464 is stored once the line to a stand-alone cylinder 8 exhaust actuator sits at a high level, typically a wire touching battery voltage. No manufacturer documents this code publicly. According to GM bulletin 20-NA-038, cylinder 8 is switched off only by DFM engines and by the LTA and LT2, whose fixed pattern is 2, 3, 5 and 8; classic AFM uses 1, 7, 6 and 4. On those engines a single solenoid also moves the exhaust lifter, and GM lists a short to power on it as P3460: with the low-side driver commanded on, less than 0.5 ohm to supply, 20 of 25 samples, Type B. Its malfunction text says cylinder 7, a copy slip in the 2019 table. The shorted output cannot pull in, so cylinder 8 simply stays active. P3463 is the ground fault.
- What you may notice
- Check engine lamp on
- Engine keeps running on all eight cylinders, slightly higher fuel use
- Likely causes
- PossibleControl wire of the cylinder 8 actuator touching a battery feed
- PossibleShorted turns in the actuator coil, resistance far too low
- RareOutput stage in the engine control module failed
- 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.