Open or damaged wiring in the exhaust valve control circuit, such as a broken wire or corroded connector; Short to voltage on the control circuit, often from chafed insulation against a power wire; Failed exhaust valve control solenoid or actuator, causing the circuit to read high voltage; Poor electrical connection at the solenoid or PCM connector, including loose pins or water intrusion; Faulty powertrain control module (PCM) driver circuit, though this is less common; Internal mechanical binding of the exhaust valve mechanism, overloading the actuator and altering circuit feedback

DTC codes / P34xx · Auxiliary emission controls / P3472

P3472Cylinder 9 Exhaust Valve Control Circuit High

Q: What does code P3472 mean?

Cylinder 9 Exhaust Valve Control Circuit High. P3472 is a generic powertrain code indicating that the powertrain control module (PCM) has detected an abnormally high voltage on the control circuit for cylinder 9's exhaust valve. This circuit typically commands a solenoid or actuator that varies exhaust valve timing or lift, and a high-voltage condition means the PCM sees voltage above the expected range, often signaling an open circuit, a short to power, or a failed actuator.

P3472 is a generic powertrain code indicating that the powertrain control module (PCM) has detected an abnormally high voltage on the control circuit for cylinder 9's exhaust valve. This circuit typically commands a solenoid or actuator that varies exhaust valve timing or lift, and a high-voltage condition means the PCM sees voltage above the expected range, often signaling an open circuit, a short to power, or a failed actuator.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Rough idle or misfire-like shudder, especially when the engine is cold
Reduced engine power or poor acceleration due to incorrect exhaust valve timing
Decreased fuel economy as the engine management system defaults to a limp mode
Occasional stalling or hesitation during light-throttle cruising
Audible ticking or unusual noise from the valve cover area if the actuator is stuck

Common causes, most likely first

Open or damaged wiring in the exhaust valve control circuit, such as a broken wire or corroded connector
Short to voltage on the control circuit, often from chafed insulation against a power wire
Failed exhaust valve control solenoid or actuator, causing the circuit to read high voltage
Poor electrical connection at the solenoid or PCM connector, including loose pins or water intrusion
Faulty powertrain control module (PCM) driver circuit, though this is less common
Internal mechanical binding of the exhaust valve mechanism, overloading the actuator and altering circuit feedback

How to diagnose and fix it

Perform a visual inspection of the exhaust valve control solenoid, its connector, and the wiring harness for damage, corrosion, or loose pins
Use a digital multimeter to check for battery voltage on the control circuit with the key on and engine off, comparing to manufacturer specifications
Disconnect the solenoid and measure resistance across its terminals to verify it is within the specified range and not open or shorted
Check for a short to power by measuring voltage on the control wire with the solenoid disconnected and the PCM connector removed
Inspect the PCM connector for corrosion or pushed-out pins, and perform a wiggle test on the harness while monitoring live data
If the circuit and solenoid test good, substitute a known-good solenoid to see if the code clears and returns
As a last resort, diagnose the PCM driver circuit or replace the PCM only after all other causes are ruled out

What a high-voltage valve code really means

A high-voltage code on an actuator circuit often results from an open circuit rather than a short, because the PCM pulls the control line up to a reference voltage and sees that voltage when the load is missing.
Technicians frequently replace the exhaust valve solenoid when the real fault is a chafed wire inside the loom near the exhaust manifold, where heat and vibration damage insulation.
This code can set intermittently due to a poor ground connection at the engine block, which raises the reference voltage seen by the PCM without any hard failure.
Some vehicles use a single control circuit for multiple cylinders, so a fault on cylinder 9 may actually be caused by a shared power or ground splice affecting other cylinders as well.
The PCM may command a default valve timing strategy when this code is active, masking driveability symptoms and leading drivers to believe the fault is minor.

Can I keep driving with P3472?

You can usually drive the vehicle short distances to a repair shop, but avoid heavy acceleration or towing because incorrect exhaust valve timing can cause overheating and further damage. If the check engine light flashes or the engine runs very poorly, stop driving and seek immediate service.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.