P3420 GMC Code - Cylinder 3 Deactivation/Intake Valve Control Circuit High
Quick Answer
The P3420 GMC code indicates an issue with the Cylinder 3 Deactivation/Intake Valve Control Circuit being too high. Common causes include Faulty intake valve control solenoid, Wiring issues in the intake valve control circuit, Malfunctioning Engine Control Module (ECM). 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
- P3420 GMC indicates Cylinder 3 Deactivation/Intake Valve Control Circuit High.
- Common causes
- Common causes include Faulty intake valve control solenoid, Wiring issues in the intake valve control circuit, Malfunctioning Engine Control Module (ECM).
- 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 P3420 GMC Description
The P3420 GMC code indicates an issue with the Cylinder 3 Deactivation/Intake Valve Control Circuit being too high. This code is typically found in vehicles with variable displacement systems, where certain cylinders are deactivated to improve fuel efficiency. In this case, Cylinder 3 is not responding properly to the deactivation command, leading to a high voltage in the intake valve control circuit.
Common Causes of P3420 GMC
- Faulty intake valve control solenoid
- Wiring issues in the intake valve control circuit
- Malfunctioning Engine Control Module (ECM)
- Mechanical issues in the engine
Symptoms of P3420 GMC
- Decreased fuel efficiency
- Rough idling
- Reduced power output
- Poor acceleration
How to Fix P3420 GMC
- Perform a comprehensive diagnostic scan to confirm the P3420 code and identify the specific cause of the issue.
- Inspect the intake valve control solenoid and wiring for any signs of damage or malfunction. Replace any faulty components.
- Test the Engine Control Module (ECM) for proper functionality and replace if necessary.
- Verify that the cylinder deactivation system is operating correctly after repairs are completed.
- Clear the fault code from the ECM memory and test drive the vehicle to ensure the issue has been resolved.
Cost to Fix P3420 GMC
The typical repair costs for addressing the P3420 GMC code can range from $200 to $500, depending on the specific cause of the issue and the cost of parts and labor in your location. It's important to note that diagnosis time and labor rates at auto repair shops can vary, so it's advisable to get a detailed estimate from a qualified mechanic before proceeding with the repairs.
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