AutoCodes – Generic – P2646

P2646 Code - 'A' Rocker Arm Actuator System Performance/Stuck Off Bank 1

Quick Answer

The Engine Control Module (ECM) commands the Rocker Arm Actuator to control the oil hydraulic circuit. Common causes include Low or overfilled engine oil, Incorrect engine oil type, Faulty 'A' Rocker Arm Actuator. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P2646 indicates 'A' Rocker Arm Actuator System Performance/Stuck Off Bank 1.
Common causes: Common causes include Low or overfilled engine oil, Incorrect engine oil type, Faulty 'A' Rocker Arm Actuator.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 50,585

How popular is this code, among other codes? Medium

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jan 24, 2019

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P2646 Description

The Engine Control Module (ECM) commands the Rocker Arm Actuator to control the oil hydraulic circuit. Oil flows through the Rocker Arm Actuator to the variable valve timing system to adjust the engine's valve timing. The variable valve timing (VVT) system is used to improve engine's performance, fuel economy or emissions. The ECM monitors the Rocker Arm Actuator circuit and sets the OBDII when the 'A' Rocker Arm Actuator circuit is out of factory specifications.

OBDII Code P2646 - 'A' Rocker Arm Actuator System Performance/Stuck Off Bank 1 - AutoCodes.com — P2646 Code - 'A' Rocker Arm Actuator System Performance/Stuck Off Bank 1

What does this mean?

What are the Possible Causes of the DTC P2646?

Low or overfilled engine oil
Incorrect engine oil type
Faulty 'A' Rocker Arm Actuator
'A' Rocker Arm Actuator harness is open or shorted
'A' Rocker Arm Actuator circuit poor electrical connection

How to Fix the DTC P2646?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P2646 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Information for Specific Makes

P2646 Acura — Rocker Arm Oil Pressure Switch Circuit Low Voltage
P2646 Buick — Intake Rocker Arm Solenoid Valve 1 Stuck Off
P2646 Cadillac — Intake Rocker Arm Solenoid Valve 1 Stuck Off
P2646 Chevrolet — Intake Rocker Arm Solenoid Valve 1 Stuck Off
P2646 Dodge — 'A' Rocker Arm Actuator System Performance/Stuck Off Bank 1
P2646 GMC — Intake Rocker Arm Solenoid Valve 1 Stuck Off
P2646 Honda — Rocker Arm Oil Pressure Switch Circuit Low Voltage

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.