If your Honda’s check engine light is on and the scanner shows a specific trouble code, you’re probably looking for answers. What does P0339 Honda code mean? This code points directly to a problem with your car’s Crankshaft Position Sensor ‘A’ Circuit, specifically an intermittent interruption in the signal it sends to the engine computer.
This sensor is crucial. It tells the engine control module (ECM) exactly where the crankshaft is and how fast it’s spinning. That information is used to control ignition timing and fuel injection. When the signal gets choppy or drops out, your Honda’s performance will suffer. You might notice issues like hard starting, stalling, poor acceleration, or a noticeable lack of power.
Let’s look at what causes this code and how you can fix it.
What Does P0339 Honda Code Mean?
The P0339 code is an OBD-II generic code. That means it has the same basic meaning across all car brands, including Honda. The full definition is “Crankshaft Position Sensor ‘A’ Circuit Intermittent.”
Here’s the simple breakdown. Your engine has a crankshaft position sensor (CKP sensor). Its job is to monitor the rotation and position of the crankshaft. It sends a steady stream of electrical pulses to the car’s computer (the ECM).
The computer uses this live data to figure out when to fire the spark plugs and inject fuel. If the ECM detects that this signal is missing, erratic, or dropping out intermittently, it will store the P0339 code and turn on the check engine light. The “A” usually refers to the primary sensor if the engine has more than one.
Common Symptoms of a P0339 Code
You’ll often feel or hear this problem before you see the code. Here are the typical signs:
- Illuminated check engine light (may flash under severe misfire conditions).
- Engine cranks but won’t start or is very hard to start.
- Engine stalls unexpectedly while idling or driving.
- Noticeable hesitation or jerking during acceleration.
- Rough idle where the engine feels like it’s shaking.
- A sudden drop in fuel economy.
- Lack of power; the car feels sluggish and unresponsive.
Main Causes of the P0339 Code in a Honda
An “intermittent” fault can be tricky, but it usually comes down to a few common issues. Here are the most likely culprits:
1. A Faulty Crankshaft Position Sensor
This is the most obvious cause. The sensor itself can fail internally due to heat, age, or vibration. The internal circuitry can break down, causing it to send a weak or inconsistent signal.
2. Damaged Wiring or Connectors
Since the code specifies “circuit,” the wiring is a prime suspect. The wires running from the sensor to the ECM can get damaged. They can be chafed by nearby components, chewed by rodents, or corroded from moisture. The electrical connector at the sensor can also become loose, corroded, or have bent pins.
3. Problems with the Sensor Ring or Reluctor Wheel
The sensor reads a toothed ring on the crankshaft or harmonic balancer. This is called a reluctor wheel. If the teeth on this ring get damaged, are clogged with metal debris, or the ring itself becomes loose, the signal will be interrupted.
4. Poor Electrical Connections or Grounds
A bad ground connection for the sensor circuit or even for the ECM can cause all sorts of erratic signals. Corrosion at a ground point is a common source of intermittent electrical faults.
5. Issues with the ECM (Less Common)
While rare, the engine control module itself could have an internal fault that prevents it from processing the sensor signal correctly. Always check everything else first before suspecting the ECM.
How to Diagnose and Troubleshoot P0339
Safety first: Make sure the engine is cool and the vehicle is parked on a level surface with the parking brake engaged. You’ll need a basic set of hand tools, a digital multimeter (DMM), and your OBD-II scanner.
Step 1: Retrieve All Codes and Check Freeze Frame Data
Use your scanner to read the code. Don’t just stop at P0339. Write down any other codes that are present. They can provide valuable clues. Then, look at the freeze frame data stored when the code was set. Note the engine RPM, load, and temperature. This info can help you recreate the condition.
Step 2: Perform a Visual Inspection
This is often where you find the problem. Here’s what to check:
- Locate the crankshaft position sensor. On most Hondas, it’s on the lower side of the engine block, near the crankshaft pulley/bottom timing belt cover.
- Carefully inspect the sensor’s wiring harness. Look for any obvious damage, cuts, or melted sections.
- Unplug the electrical connector. Check for corrosion (green or white powder), bent pins, or a loose fit. Make sure it clicks securely when reconnected.
- Look at the area around the sensor for oil leaks. Sometimes a leaking front main seal or oil pan gasket can coat the sensor in oil, causing issues.
- If possible, inspect the reluctor wheel teeth for damage or debris. You may need to remove the sensor to do this.
Step 3: Test the Sensor and Circuit
If the visual check shows nothing, you’ll need to test with a multimeter. You’ll need a repair manual for your specific Honda model to get the exact pinout and resistance values. The general process is:
Resistance Test (Ohms):
- Disconnect the sensor.
- Set your multimeter to Ohms (Ω).
- Touch the meter probes to the two terminals of the sensor itself (not the harness).
- Compare your reading to the specification in the manual. It’s usually a few hundred ohms. An infinite (open) or zero (short) reading means a bad sensor. A reading that drifts is also a sign of failure.
Voltage and Signal Test:
This is more advanced. With the connector plugged in and the key in the “ON” position, you can back-probe the wiring harness to check for reference voltage from the ECM (often 5V or 12V). You can also check for an AC voltage signal while cranking the engine. A healthy sensor will produce a small AC voltage that fluctuates as the engine turns over.
Step 4: Check Wiring Continuity and Grounds
Use your multimeter’s continuity setting to check for breaks in the wires between the sensor connector and the ECM connector. Also, locate and clean the relevant ground points. They are often on the thermostat housing or intake manifold.
Repair Instructions and Tips
Once you’ve found the cause, the repair can be straightforward.
Replacing the Crankshaft Position Sensor
- Disconnect the negative battery cable for safety.
- Unplug the electrical connector from the sensor.
- Remove the single mounting bolt (usually a 10mm).
- Gently twist and pull the sensor straight out of its bore.
- Compare the new sensor with the old one. Ensure the O-ring is in place (often pre-installed). Lightly lubricate the O-ring with a bit of clean engine oil.
- Insert the new sensor and tighten the bolt to the specified torque (don’t over-tighten).
- Reconnect the electrical plug and the battery cable.
Repairing Damaged Wires
For minor wire damage, use solder and heat-shrink tubing for a permanent, waterproof fix. Do not use twist-on connectors or electrical tape alone in the engine bay—they will fail.
Clearing the Code and Test Drive
After the repair, use your scanner to clear the P0339 code. This will also turn off the check engine light. Then, take the car for a thorough test drive. Try to replicate the conditions from the freeze frame data (similar RPM, engine load, etc.). The goal is to ensure the light does not come back and the symptoms are gone.
If the code returns immediately, you may have missed a second issue, like a problem with the reluctor wheel or a deeper wiring fault.
Frequently Asked Questions (FAQ)
Can I drive my Honda with a P0339 code?
It is not recommended. The problem can cause sudden stalling or severe misfires, which could leave you stranded or create a safety hazard in traffic. The sooner you adress it, the better.
How much does it cost to fix a P0339 code?
The cost varies. A genuine Honda CKP sensor typically costs between $50 and $150 for the part. If you do it yourself, that’s your total cost. At a shop, with 1-2 hours of labor, total repair costs can range from $200 to $400 on average.
What’s the difference between P0335 and P0339?
P0335 indicates a complete circuit malfunction (e.g., no signal at all). P0339 specifically means the signal is there but is dropping out or becoming erratic intermittently. The causes are very similar, but P0339 points more strongly to wiring or connection issues.
Will a bad crankshaft sensor always throw a code?
Not always, especially in early stages. But once the signal disruption is significant enough for the ECM to notice, it will set a code like P0339 or P0335. Intermittent problems might turn the light on and off.
Can a bad battery cause a P0339 code?
Yes, indirectly. A weak battery or failing alternator can cause low system voltage. This can make sensors act erratically and the ECM to misread signals, potentially triggering intermittent codes like P0339. It’s a good idea to check your battery voltage as part of diagnosis.
Fixing a P0339 code in your Honda is usually a manageable DIY job with the right tools and patience. Start with a careful visual inspection—you might be surprised how often the problem is a simple loose connection or damaged wire. By following a logical troubleshooting process, you can get your Honda running smoothly again and avoid a costly trip to the repair shop.