P2652 OBD-II Trouble Code: B Rocker Arm Actuator System Stuck On Bank1

P2652 code definition

B Rocker Arm Actuator System Stuck On Bank1

What the P2652 code means

The Engine control module (ECM) has a wide variety of jobs, but one of the most critical is to keep the supply of oil within mechanically safe ranges. The engine depends on oil to produce a frictionless environment for the engine components moving at extremely rapid speeds. Without oil, internal engine components, such as rocker arms, will overheat and may scrape against their mating surface, instead of sliding.

The ECM uses sensors such as a rocker arm actuator, or oil pressure switch, to regulate the flow of oil to the engine. If trouble code P2652 sets, it means the ECM has detected an abnormality regarding the feedback it is receiving from the rocker arm actuator.

The rocker arm actuator is an oil pressure switch which controls the flow of oil to critical upper engine cylinder head components. The rocker arm actuator is a unit consisting of oil passages governed by the ECM; passage operation will alternate depending on the driving conditions, and each particular passage will vary oil pressure to the cylinder head.

The ECM has a “blueprint” of the manufacturer’s required oil pressure for the vehicle, and it will try to keep the oil pressure within that range by operating the passages within the rocker arm actuator to increase or limit the oil flow to the cylinder head. The actuator will measure how much oil is flowing through it and report it to the ECM. The ECM will administer changes where it sees fit. If the rocker arm actuator is out of range and the ECM is unable to make the changes needed to bring the response from the actuator back to a desirable range, a code P2652 may set.

What causes the P2652 code?

• Low or overfilled oil
• Faulty rocker arm actuator
• Incorrect oil type
• Faulty ECM
• Engine mechanical fault

What are the symptoms of the P2652 code?

• Check Engine Light illumination
• Audible tap or tick from engine
• Vehicle may enter limp mode and limit speed to under 40 miles per hour
• Faulty oil pressure sensor
• Faulty oil pump

How does a mechanic diagnose the P2652 code?

• Checks the oil pressure of the engine
• Inspects the screens of the oil pressure sensor and rocker arm actuator
• Inspects the quality and level of the engine oil
• Inspects the wiring of the oil pressure sensor and rocker arm actuator for opens or shorts in the circuit (also tests with a multimeter)
• Checks Technical Service Bulletins (TSB’s) - some vehicles do have a TSB related to the P2652 trouble code

Common mistakes when diagnosing the P2652 code

Many mechanics may misidentify the location of the rocker arm actuator at fault. Generally, there are two rocker arm actuators (A, B). It is important to use a proper diagram for your specific vehicle to distinguish the two actuators.

How serious is the P2652 code?

It is fairly serious because the rocker arm actuator controls the oil flow to critical upper engine components. The rocker arm actuator must be in working order for the engine to receive proper lubrication. Lack of lubrication is a common cause of engine failure.

What repairs can fix the P2652 code?

• Replacing a faulty oil pump
• Cleaning the screens on the oil pressure sensor or rocker arm actuator
• Changing the oil and filter
• Repairing or replacing the ECM
• Replacing a faulty oil pressure sensor or rocker arm actuator
• Repairing any damaged wiring, open or shorted circuits related to the oil pressure sensor or rocker arm actuator

Additional comments for consideration regarding the P2652 code

Researching the TSB’s pertaining to your specific vehicle can greatly assist in a proper, correct, and expedited repair

Need help with a P2652 code?

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