Faulty oil control solenoid or valve actuator for cylinder 9's exhaust valve; Degraded or contaminated engine oil causing sluggish solenoid response; Wiring damage or poor electrical connection at the solenoid or actuator; Mechanical wear or sticking in the exhaust valve control mechanism; Failed oil pressure sensor or low oil pressure affecting the variable valve system; Software calibration issue in the powertrain control module (rare)

DTC codes / P34xx · Auxiliary emission controls / P3470

P3470Cylinder 9 Exhaust Valve Control Performance

Q: What does code P3470 mean?

Cylinder 9 Exhaust Valve Control Performance. P3470 indicates that the powertrain control module has detected a performance problem with the exhaust valve control system for cylinder 9, which is part of a variable valve timing or cylinder deactivation system on engines that use such technology. The computer monitors the valve's response to commanded changes and sets this code when the actual valve behavior does not match the expected performance within a calibrated threshold.

P3470 indicates that the powertrain control module has detected a performance problem with the exhaust valve control system for cylinder 9, which is part of a variable valve timing or cylinder deactivation system on engines that use such technology. The computer monitors the valve's response to commanded changes and sets this code when the actual valve behavior does not match the expected performance within a calibrated threshold.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

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 or under light load
Reduced engine power or sluggish acceleration due to improper valve timing
Increased fuel consumption as the engine compensates for poor cylinder efficiency
Audible ticking or tapping from the valve cover area if the control mechanism is mechanically worn
In some cases, the engine may enter limp mode to protect the valvetrain

Common causes, most likely first

Faulty oil control solenoid or valve actuator for cylinder 9's exhaust valve
Degraded or contaminated engine oil causing sluggish solenoid response
Wiring damage or poor electrical connection at the solenoid or actuator
Mechanical wear or sticking in the exhaust valve control mechanism
Failed oil pressure sensor or low oil pressure affecting the variable valve system
Software calibration issue in the powertrain control module (rare)

How to diagnose and fix it

Verify engine oil level and condition; change oil and filter if overdue or contaminated
Perform a visual inspection of the cylinder 9 exhaust valve control solenoid and its wiring for damage or corrosion
Use a scan tool to command the solenoid on and off and observe the actual valve timing response
Check oil pressure at the cylinder head to ensure the variable valve system receives adequate pressure
Test the solenoid resistance and compare to factory specifications; replace if out of range
Inspect the valve control mechanism for mechanical binding or wear, requiring disassembly if necessary
After repairs, clear the code and perform a drive cycle to verify the fix and ensure the monitor runs

Oil Quality and Solenoid Response

Many technicians replace the exhaust valve solenoid only to find the root cause is sludged oil blocking the oil passages to the actuator, so an oil flush may be necessary.
A failing oil pressure sensor can mimic a valve control fault by reporting low pressure to the PCM, causing it to set P3470 even when the valve system is healthy.
The code can be set by a momentary electrical glitch, so always check for related history codes and freeze-frame data before condemning parts.
On engines with cylinder deactivation, a stuck exhaust valve can cause the affected cylinder to pump air, leading to catalyst overheating and additional codes.
Wiring harness chafing near the valve cover is a common hidden cause, especially on engines with high vibration or after previous repairs.

Can I keep driving with P3470?

You can usually drive the vehicle with P3470 set, but avoid heavy acceleration and towing until the fault is repaired. Prolonged driving with a malfunctioning exhaust valve control can lead to catalyst damage or further engine wear.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

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