What Is Car Fault Code P0407? Diagnose & Clear It with iCarsoft CR Pro S
If your check engine light lights up and your diagnostic tool pulls up P0407, you’re facing an issue with your vehicle’s exhaust gas recirculation (EGR) system—specifically the EGR position sensor. This sensor plays a critical role in regulating exhaust gas flow back into the engine, optimizing fuel efficiency and reducing emissions. Ignoring P0407 can lead to rough idling, decreased performance, and failed emissions tests. In this guide, we’ll break down what P0407 means, why it occurs, and how the iCarsoft CR Pro S—your all-in-one diagnostic solution—can help you pinpoint and resolve the problem efficiently.
iCarsoft CR Pro S testing EGR position sensor to diagnose P0407 fault code
What Exactly Is Fault Code P0407?
P0407 is a generic OBD-II trouble code defined as “Exhaust Gas Recirculation (EGR) Position Sensor Circuit Low Input”. The EGR position sensor monitors the position of the EGR valve, sending real-time data to the ECU (Engine Control Unit). When the sensor transmits an abnormally low electrical signal (or no signal at all), the ECU triggers P0407, indicating a communication failure between the sensor and the ECU.
This code is common across gasoline and diesel vehicles, as the EGR system is a standard component in modern engines. The good news? With the right diagnostic tool, you can identify the root cause without costly dealership visits.
Why Does P0407 Happen? Common Causes
P0407 typically stems from issues related to the EGR position sensor or its surrounding components:
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Faulty EGR Position Sensor: The sensor itself may be worn out, contaminated with carbon buildup, or electrically defective.
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Wiring or Connector Issues: Damaged, frayed, or shorted wires, or a loose/corroded connector between the sensor and ECU.
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Clogged EGR Valve: Carbon deposits on the EGR valve can prevent it from moving freely, damaging the sensor.
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Low Battery Voltage: A weak battery can cause unstable electrical signals to the sensor.
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ECU Malfunction: Rarely, the engine control unit may fail to interpret the sensor’s signal correctly.
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Vacuum Leaks: Leaks in the EGR system’s vacuum lines can disrupt sensor operation.
Why the iCarsoft CR Pro S Is Ideal for P0407
When it comes to diagnosing and fixing P0407, the iCarsoft CR Pro S outperforms basic scanners by offering deep EGR system insights and global compatibility. Here’s why it’s your best tool:
Full EGR System Scans
Unlike basic scanners that only read the code, the CR Pro S dives into the EGR system, checking the position sensor, valve, and related wiring.
Live Data Monitoring
View real-time EGR sensor voltage and valve position to verify if the sensor is sending low input.
Bi-Directional Control
Test the EGR valve and sensor by sending commands—confirm if the sensor responds correctly to valve movements.
Global Vehicle Support
Works with over 60 makes (Ford, Toyota, BMW, Honda, Mercedes-Benz, etc.)—P0407 is no match for its wide compatibility.
One-Click Code Clear
After fixing the issue, erase P0407 and turn off the check engine light in seconds.
Lifetime Free Updates
Stay compatible with new EGR system designs and code definitions.
Feedback Function
Get customized repair suggestions from certified professionals tailored to your car’s make and model.
How to Diagnose & Fix P0407 with the CR Pro S (Step-by-Step)
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1. Connect the CR Pro S
Plug the tool into your car’s OBD-II port (under the dashboard) and turn on the ignition.
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2. AutoVIN Identify
The tool automatically detects your vehicle’s details—no manual entry needed.
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3. Scan for Codes
Select “Full System Scan” or “Engine System Scan” to retrieve P0407 and related codes (e.g., P0401 for EGR flow issues).
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4. Check Live Data
Monitor EGR position sensor voltage—abnormally low readings confirm a sensor or wiring problem.
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5. Test Components
Use bi-directional control to activate the EGR valve—if the sensor doesn’t register movement, it’s likely faulty.
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6. Fix the Root Cause
Replace the sensor, repair wiring, clean the EGR valve, or fix vacuum leaks (based on your findings).
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7. Clear the Code
Use the “Erase Codes” function to reset P0407 and the check engine light.
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8. Re-Scan & Verify
Run a follow-up scan to ensure the code doesn’t return—confirm the EGR system is working properly.
FAQs About P0407 & the iCarsoft CR Pro S
Q: Can I drive with P0407?
A: You can drive short distances, but long-term use may cause reduced fuel efficiency, rough idling, or engine damage. Diagnose it promptly with the CR Pro S.
Q: Will the CR Pro S work with my car to diagnose P0407?
A: Yes! The CR Pro S supports over 60 global makes and all 1996+ OBD-II compliant vehicles—whether you drive a gasoline or diesel car, it handles P0407.
Q: Do I need mechanical experience to use the CR Pro S for P0407?
A: No! The tool’s 5-inch touchscreen, AutoVIN function, and clear instructions make it user-friendly for beginners. It even highlights EGR system components for easy reference.
Q: Can the CR Pro S distinguish between a faulty sensor and wiring issues?
A: Absolutely. Live data shows sensor voltage—if voltage is low but wiring looks intact, the sensor is faulty. If voltage fluctuates with wire movement, wiring is the culprit.
Q: After fixing P0407, will the CR Pro S clear the code permanently?
A: Yes—once the root cause (e.g., faulty sensor, clogged valve) is addressed, the “Erase Codes” function clears P0407 permanently. If it returns, the issue wasn’t fully resolved.
Q: Is the CR Pro S better than a basic scanner for P0407?
A: Basic scanners only show P0407—they can’t test the EGR valve or monitor sensor voltage. The CR Pro S identifies why the code occurred, saving you from unnecessary part replacements.
Q: Does the CR Pro S support diesel vehicles with P0407?
A: Yes! Diesel engines rely heavily on EGR systems, and the CR Pro S includes specialized diesel EGR diagnostic functions to handle P0407 in diesel cars, trucks, and SUVs.
Q: How often should I update the CR Pro S for P0407 diagnostics?
A: The CR Pro S offers lifetime free Wi-Fi updates—update every 3–6 months to ensure compatibility with new EGR system technologies and code definitions.
Final Thoughts: Don’t Let P0407 Compromise Your Engine
Fault code P0407 may seem complex, but with the iCarsoft CR Pro S, you can diagnose and fix it from your garage—no expensive dealership visits required. Its deep EGR system coverage, live data monitoring, and bi-directional control take the guesswork out of repairs, whether you’re a DIY enthusiast or professional mechanic.
Invest in the iCarsoft CR Pro S today to tackle P0407 and hundreds of other engine-related codes—keep your car running efficiently, cleanly, and reliably.
