Navigating the complexities of your vehicle’s onboard diagnostic system can be daunting, especially when faced with error codes. Among these, OBD2 code P0335 is a common concern for car owners. This code signals a potential issue within the Crankshaft Position Sensor (CKP) circuit, a critical component in your engine’s operation. Let’s delve into what this code means, its potential causes, and how it can be addressed.
The P0335 code, as defined by the Society of Automotive Engineers (SAE), indicates a “Crankshaft Position Sensor ‘A’ Circuit Malfunction.” Essentially, your car’s Powertrain Control Module (PCM) is detecting an irregular or absent signal from the crankshaft position sensor. This sensor plays a vital role in monitoring the crankshaft’s position and rotational speed, data crucial for fuel injection timing, ignition spark delivery, and overall engine synchronization.
A malfunctioning CKP sensor or circuit can stem from various factors. These include:
- Sensor Failure: The sensor itself might be faulty due to wear and tear, damage, or internal electrical issues.
- Wiring Problems: Damage, corrosion, or loose connections in the wiring harness leading to the CKP sensor can disrupt signal transmission.
- Reluctor Ring Damage: The reluctor ring, a toothed wheel that the CKP sensor reads, could be damaged or misaligned, leading to inaccurate readings.
- PCM Issues: In rare cases, the PCM itself might be misinterpreting sensor data or have internal faults.
Interestingly, some vehicles, particularly older models, might trigger a P0335 code due to software glitches in the PCM. As highlighted in technical service bulletins (TSBs), certain Mitsubishi Eclipse models were known to exhibit false P0335 codes. These false positives were often resolved through PCM reprogramming with updated software logic.
For instance, Mitsubishi issued TSB−06−13−006 specifically to address PCM reprogramming for DTC P0335 and P0340 in Eclipse models. The updated ROM revisions contained fixes for these false codes, ensuring more accurate diagnostics. While dealerships can perform these updates, it’s crucial to ensure that any existing custom tunes or aftermarket calibrations are compatible with the new ROM version to avoid unintended consequences.
Addressing a P0335 code promptly is essential. Ignoring this issue can lead to:
- Engine Misfires: Incorrect fuel and spark timing due to faulty CKP sensor data can cause engine misfires and rough running.
- Stalling: In severe cases, a complete loss of CKP signal can result in engine stalling.
- Reduced Fuel Efficiency: Engine inefficiency due to timing issues can lead to decreased fuel economy.
- Check Engine Light Illumination: The most immediate symptom is the illumination of the check engine light on your dashboard.
If you encounter a P0335 code, a systematic diagnostic approach is recommended. This typically involves:
- Code Verification: Use an OBD2 scanner to confirm the presence of the P0335 code and check for any other related codes.
- Visual Inspection: Inspect the CKP sensor and its wiring for any visible damage, loose connections, or corrosion.
- Sensor Testing: Use a multimeter to test the CKP sensor’s resistance and signal output to determine if it’s functioning correctly.
- Circuit Testing: Check the continuity and voltage in the CKP sensor circuit wiring to identify any breaks or shorts.
- PCM Reprogramming (if applicable): For vehicles known to have software-related false positives, consider a PCM reprogramming to the latest software revision.
In conclusion, OBD2 code P0335 signals a malfunction in the crankshaft position sensor circuit, a vital system for engine management. While it can indicate genuine sensor or wiring issues, it’s also important to be aware of potential software-related false positives, especially in older vehicles. A thorough diagnostic process is crucial to accurately identify the root cause and implement the appropriate repair, ensuring your vehicle runs smoothly and efficiently.
