Faulty exhaust valve control solenoid or actuator; Damaged or chafed wiring harness to the solenoid (short to ground or open circuit); Corroded or loose electrical connector at the solenoid; Failed PCM driver for that circuit (rare but possible); Internal mechanical binding of the exhaust valve or rocker arm causing excessive current draw; Oil sludge or debris clogging the solenoid screen, leading to low voltage feedback

DTC codes / P34xx · Auxiliary emission controls / P3471

P3471Cylinder 9 Exhaust Valve Control Circuit Low

Q: What does code P3471 mean?

Cylinder 9 Exhaust Valve Control Circuit Low. P3471 means the powertrain control module (PCM) has detected a low-voltage condition on the electrical circuit that controls the exhaust valve for cylinder 9, which is typically managed by a variable valve timing or cylinder deactivation solenoid. The computer commands the valve to change position and monitors the circuit, finding the voltage below the expected threshold, indicating a short to ground, an open circuit, or a faulty actuator.

P3471 means the powertrain control module (PCM) has detected a low-voltage condition on the electrical circuit that controls the exhaust valve for cylinder 9, which is typically managed by a variable valve timing or cylinder deactivation solenoid. The computer commands the valve to change position and monitors the circuit, finding the voltage below the expected threshold, indicating a short to ground, an open circuit, or a faulty actuator.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough idle or misfire sensation, especially when the engine is cold or under light load
Reduced engine power or sluggish acceleration due to improper valve timing
Increased fuel consumption as the engine compensates for poor breathing
Occasional stalling or hesitation when coming to a stop
Audible ticking or tapping from the valve cover area if the solenoid is stuck

Common causes, most likely first

Faulty exhaust valve control solenoid or actuator
Damaged or chafed wiring harness to the solenoid (short to ground or open circuit)
Corroded or loose electrical connector at the solenoid
Failed PCM driver for that circuit (rare but possible)
Internal mechanical binding of the exhaust valve or rocker arm causing excessive current draw
Oil sludge or debris clogging the solenoid screen, leading to low voltage feedback

How to diagnose and fix it

Perform a visual inspection of the solenoid connector and wiring for damage, corrosion, or loose pins
Measure resistance of the solenoid with a multimeter and compare to manufacturer specification
Check for battery voltage at the solenoid connector with the key on and engine off; repair open circuit if absent
Test the control circuit for a short to ground using a multimeter or test light; repair wiring as needed
Swap the solenoid with a known-good one from another cylinder to see if the code moves
If the circuit and solenoid test good, check for mechanical binding of the exhaust valve and rocker arm
Clear the code and perform a road test to verify the repair; if the code returns, diagnose the PCM driver

Don't overlook the wiring harness

A chafed wire behind the valve cover or near a hot exhaust component is a common cause that many technicians miss when they replace the solenoid first.
The code can be set by a poor ground connection at the engine block, which raises the circuit's reference voltage and triggers a false low reading.
Oil sludge from infrequent oil changes can clog the solenoid screen, causing low voltage feedback without any electrical fault.
A failing PCM driver is rare, but it should be suspected only after all wiring and solenoid tests pass and the code persists.
On engines with cylinder deactivation, a stuck exhaust valve can cause the solenoid to draw excessive current, setting this code without a wiring issue.

Can I keep driving with P3471?

You can drive the vehicle short distances to a repair shop, but avoid heavy acceleration or towing because the engine may misfire or lose power. Prolonged driving with this code can damage the catalytic converter due to unburned fuel.

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.