What does it mean?
P3455 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Cylinder 7 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
- The check engine light (MIL) is on and the code is stored together with freeze frame data.
- Cylinder deactivation is switched off, so the engine runs on all cylinders and fuel consumption rises noticeably in steady cruising.
- Rough running, shudder or a misfire sensation traced to cylinder 7.
- Ticking from the valvetrain over that cylinder, most audible at idle.
- When the exhaust side does not switch as commanded, trapped combustion gas can cause popping in the intake or exhaust and unstable fuel trims.
- Other valve control solenoids on the same harness branch may report faults at the same time, because the module protects its outputs, and the MIL usually returns within one drive after clearing.
Likely causes
- Control wire rubbed through and shorted to ground against the cylinder head, a bracket or the valve cover edge.
- Internally shorted solenoid winding, measuring well below the specified resistance.
- Oil, water or coolant inside the connector creating a leakage path to ground.
- Harness pinched under the intake manifold, the valve cover or a clamp after earlier engine work.
- Corroded terminals bridging adjacent pins in the solenoid or module connector.
- Heat-hardened insulation on the exhaust-side branch cracking and letting the conductor touch the head or the manifold.
- Shorted ECM output driver, which is a valid conclusion only after the harness and the solenoid have both been proven good.
How to fix it
- Note the freeze frame conditions and check whether solenoids on the same harness branch also report low-side faults; a group of faults points at the harness, a single one at the solenoid.
- Unplug the solenoid and measure both its winding resistance and its resistance to engine ground; a shorted or grounded winding condemns the solenoid.
- With the solenoid disconnected, test the control wire from the module connector for a short to ground.
- Follow the harness where it crosses metal edges, brackets and the hot side of the engine, looking for melted, pinched or rubbed-through insulation.
- Open and dry the connector, check for oil or coolant intrusion and fix the leak that let the fluid in, otherwise the fault comes straight back.
- Repair the damaged harness section or fit a solenoid of original specification, so the coil resistance matches what the driver expects.
- Recheck the output with an actuator test after the repair; suspect the ECM only if the output stays shorted with nothing connected to it.