P2655
"A" Rocker Arm Actuator Control Circuit/Open (Bank 2)
- Severity
- High
- Driving
- Drive only to a garage
An open circuit in the "A" rocker arm actuator control on bank 2. Switching rocker arms change how far the valves open - or stop them opening at all, on engines that deactivate cylinders - and this actuator is how the module controls them. With the circuit open, the rockers stay in whichever state they were last in.
Possible causes
- CommonLow, dirty or wrong-viscosity engine oil
- CommonFailed rocker arm actuator solenoid
- CommonOil control valve blocked with debris
- CommonCorroded or oil-contaminated connector
- CommonWiring damage in the valve cover harness
- PossibleFailed or collapsed switching rocker arm
- PossibleLow oil pressure from a worn pump or clogged pickup
What you might notice
- Misfire or rough running
- Ticking or tapping from the top of the engine
- Loss of power at one end of the rev range
- Worse fuel economy
- Check engine light on
What to check, in order
- Check the engine oil level, condition and viscosity first. These actuators are driven by oil pressure through small solenoid valves, so oil that is low, degraded or the wrong grade causes more faults here than wiring ever does.
- Ask when the oil was last changed. Extended or missed oil changes are the biggest single cause of failures in oil-actuated valve systems.
- Listen for a tick from the top of the engine, which points at the rocker mechanism rather than the solenoid.
- Inspect the connector for oil contamination and corrosion.
- Measure the solenoid winding resistance against specification.
- Read all codes - misfire codes alongside these identify which cylinders are affected.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Computer output circuits and control module
P2600P2601P2602P2603P2604P2605P2606P2607P2608P2609P2610P2611P2612P2613P2614P2615P2616P2617P2618P2619P2620P2621P2622P2623P2624P2625P2626P2627P2628P2629P2630P2631P2632P2633P2634P2635P2636P2637P2638P2639P2640P2641P2642P2643P2644P2645P2646P2647P2648P2649P2650P2651P2652P2653P2654P2655P2656P2657P2658P2659P2660P2661P2662P2663P2664P2665P2666P2667P2668P2669P2670P2671