KlaroFault codeP2646
MODERATEA Rocker Arm Actuator System Performance or Stuck Off (Bank 1)
What this code means
A Rocker Arm Actuator System Performance or Stuck Off (Bank 1).
“Bank 1” is the side of the engine that holds cylinder number 1; “Bank 2” only exists on V and flat engines. An in-line engine has a single bank.
P2646 is a generic code: it means the same thing on every make. P2646 belongs to family P26xx — Control unit and auxiliary outputs. Its page explains how to read a code and groups all its codes by part.
Type of fault
The controlled part — solenoid, torque converter clutch — does not respond as commanded and stays stuck in one position. The cause can be electrical, but also hydraulic or mechanical: dirty fluid, a sticking valve. On an automatic gearbox, the fluid level and condition are the first thing to check.
Variable valve lift (rocker arm actuator)
Some engines change their valve lift with engine speed, using rocker arms locked together by small oil-pressure pistons and controlled by a solenoid valve. Honda's VTEC is the best-known example.
What you notice
Lack of power at high revs when the high lift does not engage, or a rough idle if it stays engaged.
How to check it
Oil is the first suspect: check the level, the viscosity and the service history. Then the control solenoid, its fine filter screen and its oil pressure switch, often bolted to the cylinder head.
Watch it live in Klaro
With an OBD2 adapter plugged in, these live readings show the part at work, when your car reports them:
- Engine RPM
- Engine oil temperature
What to do
Have it checked this week. The car remains usable, but the fault will not clear itself and will fail the roadworthiness test.
Clearing a code switches the light off but repairs nothing: if the fault remains, the code comes back. Clearing a fault code yourself →
How to read this code
- PPowertrain
- 2standardised code
- 6Control unit and auxiliary outputs
- 46P2646
