How to Diagnose and Fix P0339 Trouble Code

AvatarByCarl Frisch

P0339 is a diagnostic trouble code (DTC) that indicates a malfunction in the crankshaft position sensor circuit. This code is set when the Engine Control Module (ECM) detects an incorrect signal from the crankshaft position sensor. The crankshaft position sensor monitors the rotation of the crankshaft and sends this information to the ECM, which uses it to determine engine timing and fuel injection.

To fix P0339, you will need to diagnose and repair the underlying problem causing this DTC. Common causes for this code include loose or corroded connections in the crankshaft position sensor circuit, an open or shorted wiring harness, defective crank sensors, or damaged camshaft timing components.

In order to diagnose and repair P0339, you must first determine what caused the code to be set. A visual inspection of the wiring harness and connections can help identify any problems with corrosion or damage. If no problems are found, then a scan tool should be used to read and record live data from the ECM. This data can help pinpoint any faulty components that may be causing the issue.

Once any faulty components have been identified and replaced, resetting or clearing the ECM should clear away any trouble codes stored in memory and allow your vehicle to operate correctly again.

What is a P0339 Code?

A P0339 code is an Diagnostic Trouble Code (DTC) that is triggered when the Powertrain Control Module (PCM) detects an irregularity in the crankshaft position sensor circuit. This code can be set when the PCM detects a voltage drop in the crankshaft position sensor circuit. This can be caused by a faulty crankshaft position sensor, loose or damaged connections, or wiring issues.

What Causes a P0339 Code?

There are several common causes of a P0339 code. The most common culprits are loose or damaged connections, a faulty crankshaft sensor, or wiring issues. In some cases, it may be caused by low engine oil levels, which can cause the crankshaft position sensor to malfunction. In other cases, it may be caused by a broken timing belt or chain. In any case, it should be addressed as soon as possible to prevent further damage from occurring to your vehicle’s engine components.

Diagnosing a P0339 Code

In order to diagnose and repair this code, it is important to first identify the cause of the issue before attempting any repairs. One of the first steps you should take is to check all connections and wiring for any signs of damage or corrosion. If you find any loose wires or connectors that could be causing the issue, they should be replaced as soon as possible. Additionally, you should check your vehicle’s oil level and top off if necessary to ensure that there is enough lubrication for your engine’s components.

If these steps do not identify and resolve the issue, then you may need to replace or repair your vehicle’s crankshaft position sensor if it has failed due to age or wear and tear. This can often be done at home with basic tools however in some cases it may require more specialized equipment and professional help in order to complete successfully.

Automobile

Automobile maintenance is an important part of keeping your vehicle running safely and efficiently. One common issue that can arise is a P0339 code, which indicates that the crankshaft position sensor (CKP) or its circuit has failed. This code can be difficult to diagnose and repair, so it’s important to have a solid understanding of how to fix a P0339 code before attempting to do so.

Checking for Diagnostic Trouble Codes

The first step in diagnosing and fixing a P0339 code is to check for diagnostic trouble codes (DTCs). DTCs are stored in the vehicle’s computer when certain components fail or malfunction. Checking for DTCs can help you identify the source of the issue, allowing you to quickly and accurately diagnose and repair the problem.

Performing Visual and Physical Inspections

Once you have identified the source of the issue, it’s time to perform a visual and physical inspection of all related components. This includes inspecting wires, connectors, and other components associated with the crankshaft position sensor (CKP). Pay special attention to any signs of corrosion or damage that could be causing an electrical fault.

Testing the Crankshaft Position Sensor Signal Output

The next step is to test the crankshaft position sensor signal output using an oscilloscope or other diagnostic equipment. This will allow you to confirm if there is a problem with the CKP itself, or if there is an issue with its wiring or connections. Once you’ve confirmed that there is an issue with either the CKP or its wiring/connections, it’s time to move on to testing alternator output voltage.

Testing Alternator Output Voltage

Testing alternator output voltage is necessary because it can help determine if there is an electrical fault caused by a faulty alternator. To test alternator voltage, connect a multimeter between two points on the vehicle’s battery terminals and measure voltage readings at different engine speeds. If your readings are lower than expected at higher engine speeds, it could indicate that there is an issue with your alternator. If this is found to be true, then replacing or repairing your alternator should fix your P0339 code.

Replace or Repair Damaged or Loose Connections and Wires

If testing reveals no issues with your alternator but still indicates that there may be an electrical fault causing your P0339 code, then replacing or repairing any damaged wires or loose connections should fix it. Make sure all connections are tight and secure before testing again; if this doesn’t solve the problem then you may need to replace any damaged wiring before retesting again for success.

FAQ & Answers

Q: What is a P0339 Code?
A: A P0339 code is an OBD-II diagnostic trouble code (DTC) that indicates that the crankshaft position sensor circuit has an intermittent connection. It is often found in vehicles with internal combustion engines.

Q: What are the Symptoms of a P0339 Code?
A: Common symptoms of a P0339 code include engine misfires, rough idling, and difficulty starting the engine. The check engine light may also be illuminated.

Q: What Causes a P0339 Code?
A: The most common causes of a P0339 code are loose or damaged connections, faulty crankshaft sensors, and wiring issues.

Q: How Is a P0339 Code Diagnosed?
A: A P0339 code can be diagnosed by checking for diagnostic trouble codes, performing visual and physical inspections, testing the crankshaft position sensor signal output, and testing alternator output voltage.

Q: How Can I Fix a P0339 Code?
A: The best way to fix a P0339 code is to replace or repair any damaged or loose connections and wires. Replacing the crankshaft position sensor may also be necessary.

In conclusion, to fix a P0339 code, it is important to inspect the wiring and connections of the crankshaft position sensor, as well as the condition of the sensor itself. If any problems are found with either the wiring or the sensor, they should be replaced or repaired. It is also important to check for any other codes that may be present in order to diagnose any other underlying issues. Once all repairs have been completed and tests have been run, the engine should be retested for proper operation.

Author Profile

Carl Frisch
Carl Frisch
With more than 30 years in the bicycle industry, I have a strong background in bicycle retailing, sales, marketing and customer service. I have a passion for cycling and a dedication to excellence. As a manager, I worked diligently to increase my capabilities and responsibilities, managing up to eleven mechanics (at Palo Alto Bicycles) and later as a working partner in my own store.

As the shop owner of Spoke n’ Word Cycles in Socorro, NM, the success of the mission was my responsibility, which I pursued passionately since we opened in 2003 through the spring of 2011. I am adept at managing owned and loan inventory, preparing weekly & annual inventory statements, and managing staff. The role as managing partner also allowed me tremendous freedom. I used this personal freedom to become more deeply involved in my own advancement as a mechanic, to spearhead local trail building, and advocating for cycling both locally and regionally.

As a mechanic, I have several years doing neutral support, experience as a team mechanic, and experience supporting local rides, races, club events. I consistently strive to ensure that bicycles function flawlessly by foreseeing issues and working with the riders, soigners, coaches and other mechanics. Even with decades of experience as a shop mechanic and team mechanic, and continue to pursue greater involvement in this sport as a US Pro Mechanic, and UCI Pro Mechanic.

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