The code P02E9: Diesel Intake Air Flow Position Sensor Circuit High points out a fault in the diesel intake air flow position sensor circuit, indicating it’s sending a higher than expected signal. This situation is most likely caused by issues within the air intake system, sensor malfunction, or wiring problems.
P02E9 quick overview
| Meaning | P02E9: Diesel Intake Air Flow Position Sensor Circuit High |
| Is it serious? | This code can be serious as it relates to the vehicle’s air intake system, which is crucial for proper engine function and emission control. |
| Possible causes | – Faulty or dirty diesel intake air flow position sensor – Damaged, corroded, or disconnected wiring and connectors – Blockage or leaks in the air intake system – Faulty EGR system affecting airflow – Outdated or corrupted ECM software |
| How to diagnose? | Inspect the air intake system: Check for any blockages, leaks, or damage that might affect airflow. Examine the sensor and wiring: Look for any signs of damage, corrosion, or disconnection in the diesel intake air flow position sensor and its associated wiring. Update ECM software: Ensure the vehicle’s engine control module (ECM) software is up-to-date and reprogram if necessary. Perform a smoke test: Conduct a smoke test to detect any hard-to-find leaks in the air intake system. Check the EGR system: Inspect the exhaust gas recirculation (EGR) system for proper functionality and cleanliness. |
P02E9 Meaning
In simpler terms, the P02E9 code means that a part of your truck’s engine that measures incoming air isn’t working right. This can make your truck run poorly and might cause other problems. It’s like when your nose is blocked, and you can’t breathe well; your truck is having a similar issue. The usual suspects are a dirty sensor, some wires that aren’t connected properly, or a blockage somewhere in the engine’s air pipes. It’s pretty important to get this checked out to keep your truck running smoothly and to prevent bigger problems down the road.
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How to fix P02E9 – learn from mechanics
I looked into P02E9 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.
Case #1: Chevrolet
Vehicle Information:
2010 Chevrolet Tahoe LT 5.3L
Issue + Repair History:
The vehicle displayed a P02E9 code for Diesel Intake Air Flow Position Sensor Circuit High. The owner reported sluggish acceleration and rough idling. Previously, the air filter and MAF sensor were replaced with no improvement.
Other OBD2 Codes + Test Results:
P02E9 – Diesel Intake Air Flow Position Sensor Circuit High
Suggestions to Fix Issue:
- Clean and inspect the air intake system for blockages or leaks.
- Check the electrical connections and wiring to the airflow position sensor.
- Consider replacing the diesel intake air flow position sensor if other diagnostics check out.
Final Fix:
Cleaning the air intake system and replacing a damaged intake hose resolved the issue, no more P02E9 code, and vehicle performance improved.
Case #2: Dodge
Vehicle Information:
2014 Dodge Ram 3500 6.7L Diesel
Issue + Repair History:
Came in with a P02E9 code and complaints of decreased fuel efficiency and occasional stalling. The fuel system was serviced six months prior.
Other OBD2 Codes + Test Results:
P02E9 – Diesel Intake Air Flow Position Sensor Circuit High
Suggestions to Fix Issue:
- Test the diesel intake air flow position sensor for proper function.
- Inspect for any diesel particulate clogs in the intake manifold.
- Evaluate the ECM for any signs of malfunction or need for an update.
Final Fix:
Replacing a faulty diesel intake air flow position sensor and updating the ECM software fixed the problem.
Case #3: Ford
Vehicle Information:
2012 Ford F-250 Super Duty 6.7L
Issue + Repair History:
Reported loss of power and a check engine light. Diagnostic revealed a P02E9 code. No prior major repairs reported.
Other OBD2 Codes + Test Results:
P02E9 – Diesel Intake Air Flow Position Sensor Circuit High
Suggestions to Fix Issue:
- Conduct a thorough inspection of the turbocharger and its components.
- Check for any signs of wear or damage to the intake air flow position sensor.
- Ensure all software is up-to-date in the vehicle’s ECM.
Final Fix:
Turbocharger servicing and replacing a worn sensor resolved the stalling and power issues.
Case #4: GMC
Vehicle Information:
2013 GMC Sierra 2500 HD 6.6L
Issue + Repair History:
Intermittent engine light with P02E9 code. The truck recently had its air filters replaced and turbocharger inspected.
Other OBD2 Codes + Test Results:
P02E9 – Diesel Intake Air Flow Position Sensor Circuit High
Suggestions to Fix Issue:
- Check for any aftermarket modifications that might affect the air intake system.
- Inspect the sensor and associated wiring for any signs of damage or corrosion.
- Perform a smoke test to identify any air leaks in the intake system.
Final Fix:
Found and repaired a small air leak in the intake system, and reset the ECM which cleared the P02E9 code.
Case #5: Volkswagen
Vehicle Information:
2009 Volkswagen Touareg TDI 3.0L
Issue + Repair History:
Client complained of rough idle and a persistent P02E9 code. Recent services include fuel injection cleaning and EGR system check.
Other OBD2 Codes + Test Results:
P02E9 – Diesel Intake Air Flow Position Sensor Circuit High
Suggestions to Fix Issue:
- Verify the functionality of the EGR system as it can affect the air flow.
- Inspect the intake manifold for any buildup or obstruction.
- Check for the latest updates on ECM and consider reprogramming if necessary.
Final Fix:
Cleaning the EGR system and reprogramming the ECM addressed the rough idle and cleared the P02E9 code.
How to diagnose P02E9
I made you an overview of solving this DTC, based on all the advice that was suggested by certified mechanics to address this issue in previously mentioned service cases.
| Advice | Diagnostic Step |
|---|---|
| Inspect the air intake system | Check for blockages, leaks, or damage in the air intake system. |
| Check sensor and wiring | Inspect the diesel intake air flow position sensor and its wiring for damage or disconnection. |
| Update ECM software | Verify if the vehicle’s ECM software is up-to-date and reprogram if necessary. |
| Conduct a smoke test | Perform a smoke test to identify any air leaks in the intake system. |
| Inspect the EGR system | Verify the functionality and cleanliness of the EGR system as it can affect airflow. |
Car Diagnostics Training
- Car Electrical basics
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- Introduction to a Bi-directional Scan tool
- OBD scanner buyer’s guide + discounts
I test OBD-II scanners and make DIY Engine diagnostics guides to help you solve your car problems without having to depend on the mechanic. A lot of them will try to scam you or are just no help at all. About Juraj Lukacko