What does it mean?
P3407 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Cylinder 1 Exhaust Valve Control Circuit Low . 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
- Malfunction indicator lamp on and the valve control system switched off by the module
- Tick or tap from the valvetrain on that cylinder
- Misfire and rough idle when the fault occurs during a mode change
- Reduced power, especially at light throttle
- Worse fuel economy on the highway
- Fault may set immediately at start-up or only after the engine warms
Likely causes
- Control wire grounded where it chafes against the head, a bracket or the engine cover
- Solenoid winding shorted internally
- Oil or coolant contamination inside the connector bridging pins
- Harness pinched during a previous repair and now touching metal
- Damaged terminal contacting the connector shell
- Loss of the supply side so the module reads the circuit as low
- PCM low-side driver stuck on
How to fix it
- Check oil level, condition and pressure before condemning any electrical part
- Unplug the solenoid and see whether the code becomes an open or high-circuit code
- Measure the solenoid resistance and its resistance to engine ground
- With the solenoid disconnected, check the control wire for a short to ground along its route
- Inspect the connector for oil ingress and repair or replace the pigtail if it is contaminated
- Repair the shorted harness section and secure it away from sharp edges and hot components
- Replace the solenoid if it tests shorted; the PCM is the last item to consider