P2647 code meaning
"A" Rocker Arm Actuator System Stuck On (Bank 1)
Powertrain system Generic code P26xx codes Check engine light
What P2647 means
Here actuator A on bank 1 is believed to stay engaged: the rocker arms remain locked in the switched mode although the controller has asked for the default lift. GM's 2015 four-cylinder table 15OBDG05 detects this with the same intrusive lift toggle as P2646 but flags a filtered pressure-ripple value that falls below its limit; conditions are 1,200 to 1,800 rpm, 40 to 230 Nm, oil pressure 50 to 1,000 kPa, Type A after one trip. On the Honda-built 3.5 L V6 (L66) in GM's 2004 and 2005 tables, the VTEC pressure switch keeps signalling oil pressure for 5 s while the solenoid is off. On i-VTEC four-cylinders, Honda's bulletin 13-021 files a high-voltage switch reading under P2647 instead. Further causes: a solenoid leaking oil or a jammed locking pin. Expect rough idle, misfire or poor low-speed response.
P2647 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 3 hours
- Clears after repairAfter a drive cycle
Symptoms of P2647
- Rough or lumpy idle
- Misfire at low load
- Sluggish response when pulling away
Common causes of P2647
- Most likelyOil control solenoid leaks oil while switched off
- PossibleLocking pin jammed in the engaged position
- PossibleFaulty rocker arm oil pressure switch (Honda VTEC)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Rocker arm actuator a b1Oil control valveOil pressure switch
What each part of P2647 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 6 | Area: computer (engine control module) and output circuits. |
| 47 | The exact fault in that area. |
What to do next
- Note P2647 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 P2647
What does P2647 mean?
P2647 means ""A" Rocker Arm Actuator System Stuck On (Bank 1)". Here actuator A on bank 1 is believed to stay engaged: the rocker arms remain locked in the switched mode although the controller has asked for the default lift. It is a generic code, so it means the same on every make.
Is it safe to drive with P2647?
Drive gently and only to a workshop. With P2647 the car can go into limp mode (reduced power) to protect itself.
Will P2647 fail an emissions test?
Yes, it can. P2647 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 P2647 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2647 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.