What does it mean?
P3448 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Cylinder 6 Exhaust Valve Control Circuit High . This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms
- MIL (check engine lamp) on and the exhaust valve strategy locked out
- Weak pull at higher rpm and a generally lifeless engine
- Slightly rough idle and an uneven exhaust note
- Valve train ticking that does not change with commanded switching
- Fuel consumption above normal
- Cylinder 6 misfire codes may be stored alongside
Likely causes
- Control wire shorted to a battery-fed circuit inside the engine harness
- Open or corroded ground return leaving the driver output floating high
- Open coil in the exhaust valve control solenoid, so the circuit is never loaded down
- Oil-fouled, corroded or loose terminals in the solenoid connector
- Heat damage to the connector or harness branch near the exhaust side
- Failed PCM (powertrain control module) driver, considered only after wiring and load tests pass
How to fix it
- Note the freeze frame conditions and try to reproduce the fault while commanding the solenoid
- Inspect the connector for oil, corrosion, heat distortion and weak terminal tension
- Back-probe the control circuit with the key on and compare with a healthy solenoid on the same bank
- With solenoid and module unplugged, check the control wire for a short to any power source
- Measure the coil resistance; an open coil alone will set a high circuit code
- Confirm the ground return is clean and low resistance
- Repair the harness or replace the solenoid, then verify normal switching with output commands