P3470 code meaning
Cylinder 9 Exhaust Valve Control Performance
Powertrain system Generic code P34xx codes Check engine light
What P3470 means
P3470 covers a cylinder 9 exhaust valve that does not follow its deactivation command although the control circuit shows no electrical fault. No manufacturer documents this code publicly; J2012 reserves the codes for cylinders 9 to 12 for engines with more than eight cylinders. The risk behind it is described in a Ford patent: an exhaust valve that keeps opening after shut-off spoils the gas cushion in the cylinder and can be detected from changes in exhaust pressure. The opposite case, a valve that stays shut on reactivation, traps hot gas under pressure. Neither the Lamborghini Aventador V12 nor the Huracán V10 publishes how their bank shut-off works, and Audi's V10 simply cuts injection and ignition, so this check has no known user. Electrical faults of the same actuator: P3469, P3471, P3472.
P3470 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 12 hours
- Clears after repairAfter a drive cycle
Symptoms of P3470
- Check engine lamp on
- Knock or jolt when cylinder 9 comes back in
- Misfire on cylinder 9 (P0309)
Common causes of P3470
- PossibleExhaust switching element of cylinder 9 stuck
- PossibleInsufficient oil pressure for the exhaust switch
- Less likelyExhaust actuator sluggish
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Cylinder deactivation solenoidLifterEngine oil
What each part of P3470 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 3 | Mixed range: generic and manufacturer-specific codes. |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| 70 | The exact fault in that area. |
What to do next
- Note P3470 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P3470
What does P3470 mean?
P3470 means "Cylinder 9 Exhaust Valve Control Performance". P3470 covers a cylinder 9 exhaust valve that does not follow its deactivation command although the control circuit shows no electrical fault. It is a generic code, so it means the same on every make.
Is it safe to drive with P3470?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P3470 fail an emissions test?
Yes, it can. P3470 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P3470 to fix?
Difficulty: hard. A typical repair takes 0.5 to 12 hours of work. This is a job for a workshop.
Will P3470 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.