P3451 indicates that the engine computer has detected a low voltage condition in the control circuit for the intake valve deactivation solenoid on cylinder 7. This usually means there is a short to ground, high resistance, or an internal failure in the solenoid, preventing the cylinder deactivation system from operating properly.
The solenoid itself may have an internal short or open circuit, causing the low voltage reading at the computer.
Chafed, corroded, or disconnected wiring and connectors in the solenoid circuit can cause a short to ground or high resistance.
Insufficient oil level or sludge can prevent the solenoid from actuating properly, sometimes triggering circuit codes alongside performance codes.
If the system uses a separate pressure switch to monitor the circuit, its failure can trigger a false low voltage condition.
The engine computer's internal driver for this specific circuit may have failed, though this is extremely rare.
Yes, the vehicle can usually be driven, but the cylinder deactivation system will be disabled, meaning the engine will run on all cylinders. You may experience a rough idle or reduced fuel economy, but it is generally not an immediate breakdown risk.
'Circuit low' means the Powertrain Control Module is seeing a lower-than-expected voltage on the control wire for the solenoid. This usually points to a short to ground, a failed solenoid, or a poor electrical connection.
No, replacing the PCM is almost never the correct fix for this code. The vast majority of the time, the issue is a failed intake valve control solenoid or a wiring problem in the engine bay. The PCM should only be considered after all solenoids and wiring have been thoroughly tested and verified as good.