Engine-CodesGMC – P1406 GMC

P1406 GMC Code - EGR Valve Pintle Position Circuit

Quick Answer

The P1406 code for GMC vehicles specifically relates to the EGR (Exhaust Gas Recirculation) Valve Pintle Position Circuit. Common causes include Faulty EGR Valve: The EGR valve itself may be faulty, leading to issues with the pintle position circuit, Wiring Issues: Loose or damaged wiring connections related to the EGR system can trigger the P1406 code, Carbon Build-Up: Accumulation of carbon deposits in the EGR valve or passages can impede proper operation. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means
P1406 GMC indicates EGR Valve Pintle Position Circuit.
Common causes
Common causes include Faulty EGR Valve: The EGR valve itself may be faulty, leading to issues with the pintle position circuit, Wiring Issues: Loose or damaged wiring connections related to the EGR system can trigger the P1406 code, Carbon Build-Up: Accumulation of carbon deposits in the EGR valve or passages can impede proper operation.
Severity
Moderate - service should be scheduled soon.
Can I drive?
The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
Table of contents Created and updated by William Orellana on Aug 19, 2024
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Code P1406 GMC Description

The P1406 code for GMC vehicles specifically relates to the EGR (Exhaust Gas Recirculation) Valve Pintle Position Circuit. This code indicates an issue with the EGR system, which is responsible for reducing harmful emissions by recirculating a portion of the exhaust gases back into the engine for combustion. The pintle position circuit is a crucial component of the EGR system as it controls the opening and closing of the EGR valve. When this circuit malfunctions, it can lead to improper EGR valve operation, affecting the engine's performance and emission levels.

OBDII Code P1406 GMC - EGR Valve Pintle Position Circuit
P1406 GMC Code - EGR Valve Pintle Position Circuit

Common Causes of P1406 GMC

  1. Faulty EGR Valve: The EGR valve itself may be faulty, leading to issues with the pintle position circuit.
  2. Wiring Issues: Loose or damaged wiring connections related to the EGR system can trigger the P1406 code.
  3. Carbon Build-Up: Accumulation of carbon deposits in the EGR valve or passages can impede proper operation.
  4. Vacuum Leaks: Leaks in the vacuum lines connected to the EGR valve can cause performance issues.
  5. PCM (Powertrain Control Module) Failure: A malfunctioning PCM can also trigger the P1406 code by sending incorrect signals to the EGR system.

Symptoms of P1406 GMC

  1. Check Engine Light: The most common symptom associated with the P1406 code is the illumination of the Check Engine Light on the dashboard.
  2. Rough Idle: The engine may experience rough idling or fluctuations in RPM while running.
  3. Decreased Fuel Efficiency: A malfunctioning EGR valve pintle position circuit can lead to decreased fuel efficiency as the engine may not operate efficiently.
  4. Engine Stalling: In severe cases, the engine may stall or hesitate during acceleration.
  5. Increased Emissions: The vehicle may fail emissions tests due to increased emissions caused by the malfunctioning EGR system.

How to Fix P1406 GMC

  1. Diagnostic Scan: Use a diagnostic scanner to retrieve the specific code and pinpoint the issue with the EGR valve pintle position circuit.
  2. EGR Valve Inspection: Inspect the EGR valve for any signs of damage or carbon build-up that may be affecting its operation.
  3. Wiring Check: Verify the integrity of the wiring connections related to the EGR system and repair any damaged wires.
  4. Vacuum System Inspection: Check the vacuum lines for leaks or blockages and address any issues found.
  5. Replace EGR Valve: If the EGR valve is found to be faulty, replace it with a new one to restore proper operation.

Cost to Fix P1406 GMC

The cost of repairing the P1406 code related to the EGR Valve Pintle Position Circuit can vary depending on the specific cause of the issue and the labor rates in your area. On average, the repair costs can range from $150 to $500, including parts and labor. It's essential to consult with a trusted mechanic or auto repair shop to get an accurate estimate based on your vehicle's make and model.

Tech Notes for P1406 GMC

The P1406 code means that the EGR valve is 10% of the expected position by the Powertrain Control Module (PCM), usually caused by carbon built up n the EGR valve. Start by cleaning the EGR valve.

When is the Code Detected?

The EGR pintle position was ±10% of the expected position.

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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 P1406 GMC Code

No Frequently Asked Questions about P1406 GMC Code found.

Discuss the causes and fixes for P1406 GMC OBDII Code

  • Replaced the EGR valve. I had code P 1406. But it still will not start it kind of backfires and I can smell fuel I can hear the fuel pump running. It ask like it's going to start but it won't. I have also replaced the crank sensor.

  • What model and year is your vehicle?

  • Its a 97 GMC 5.7

  • Unless the EGR valve is open, I doubt the problem with the EGR is causing the no start situation. Try disconnecting the EGR valve to see if that makes any difference. Do you have spark at the spark plugs?

  • It's trying to start sometimes it just pops. Or if runs for a short time maybe hitting on a few cylinders