P2652 — Rocker arm actuator stuck on bank 1

The engine's rocker arm actuator on bank 1 is stuck in the 'on' position, affecting valve timing. This usually triggers the code because the actuator's control system detects it isn't moving as expected. It can cause rough running, reduced fuel efficiency, or increased emissions.

Common causes

The cause is almost always one of a few things. Here they are — P2652 rarely comes from anything outside this list:

• Faulty rocker arm actuator solenoid
• Wiring or connector issues in actuator circuit
• Low or dirty engine oil affecting actuator movement
• Mechanical failure inside the actuator
• Faulty engine control module (rare)

Where to start

In the order a sensible mechanic would work — the cheap checks first, the expensive replacements only after:

1. Check and clean electrical connectors at actuator
2. Inspect wiring for damage or shorts
3. Change engine oil and filter if dirty or old
4. Test actuator operation and replace if faulty
5. Replace engine control module only if all else fails

That is what holds for P2652 in general. From here it depends on your engine — tell me which car it is and what it does, and I will give you the steps for it: real procedures, torque figures and diagrams instead of general advice.