AutoCodes – GMC – P2647 GMC

P2647 GMC Code - Intake Rocker Arm Solenoid Valve 1 Stuck On

Quick Answer

The rocker arm actuator system enables the Engine Control Module (ECM) to change the camshaft lift and duration while the engine is operating. Common causes include Faulty Intake Rocker Arm Solenoid Valve 1, Intake Rocker Arm Solenoid Valve 1 harness is open or shorted, Intake Rocker Arm Solenoid Valve 1 circuit poor electrical connection. 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: P2647 GMC indicates Intake Rocker Arm Solenoid Valve 1 Stuck On.
Common causes: Common causes include Faulty Intake Rocker Arm Solenoid Valve 1, Intake Rocker Arm Solenoid Valve 1 harness is open or shorted, Intake Rocker Arm Solenoid Valve 1 circuit poor electrical connection.
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 1,621

How popular is this code, among other codes? Low

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 10, 2020

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P2647 GMC Description

The rocker arm actuator system enables the Engine Control Module (ECM) to change the camshaft lift and duration while the engine is operating. The camshaft has 3 lobes for each intake valve. The inner lobe is for low lift and the 2 outer lobes are for high lift. The rocker arm solenoid valve controls the 2-step lift by controlling the oil flow to the rocker arm. In default mode, a locking pin locks the inner and outer mechanisms of the rocker arm together to provide high lift. When low lift is commanded, oil pressure retracts a locking pin within the rocker arm.
The rocker arm solenoid valve receives a signal from the ECM. The ECM controls the rocker arm solenoid valve by supplying a 12 V PWM signal. The ECM supplies a ground to the low reference circuit.

OBDII Code P2647 GMC - Intake Rocker Arm Solenoid Valve 1 Stuck On - AutoCodes.com — P2647 GMC Code - Intake Rocker Arm Solenoid Valve 1 Stuck On

What does this mean?

What are the Possible Causes of the DTC P2647 GMC?

Faulty Intake Rocker Arm Solenoid Valve 1
Intake Rocker Arm Solenoid Valve 1 harness is open or shorted
Intake Rocker Arm Solenoid Valve 1 circuit poor electrical connection

How to Fix the DTC P2647 GMC?

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 P2647 GMC 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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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.

Frequently Asked Questions about P2647 GMC Code

1. What does the OBDII code P2647 mean on a GMC vehicle?

The code P2647 indicates that the Intake Rocker Arm Solenoid Valve 1 is stuck in the "on" position, which can affect the valve timing and engine performance.

2. What are common symptoms of code P2647 in GMC vehicles?

Symptoms may include poor engine performance, rough idling, reduced fuel efficiency, an illuminated check engine light, and potentially a lack of acceleration.

3. What causes the Intake Rocker Arm Solenoid Valve to get stuck on?

Common causes include a faulty rocker arm solenoid valve, clogged oil passages, low or dirty engine oil, or an issue with the engine control module (ECM).

4. Can low oil levels cause the P2647 code to appear?

Yes, low oil levels or dirty oil can cause insufficient lubrication, leading to the solenoid valve becoming stuck.

5. How do you diagnose the P2647 code on a GMC?

Diagnosis typically involves checking oil levels and condition, inspecting the rocker arm solenoid valve for damage, testing the solenoid with a multimeter, and scanning for additional trouble codes.

6. Is it safe to drive with the P2647 code active?

It is not recommended to drive with this code active, as it can lead to engine damage or poor performance if not addressed promptly.

7. How do you fix the P2647 code on a GMC vehicle?

Repairs may include replacing the rocker arm solenoid valve, cleaning oil passages, performing an oil change, or reprogramming or replacing the ECM if necessary.

8. How much does it cost to fix the P2647 code on a GMC?

Costs can vary, but replacing the rocker arm solenoid valve typically ranges from $150 to $300, depending on parts and labor.

9. What tools are needed to troubleshoot the P2647 code?

Youâ€™ll need an OBDII scanner, a multimeter, and basic hand tools to inspect and test the solenoid valve and related components.

10. Can regular maintenance help prevent the P2647 code?

Yes, maintaining proper oil levels and performing regular oil changes with the recommended oil type can prevent issues with the rocker arm solenoid valve.