Experiencing issues with your Nissan Maxima and encountering the OBDII code P0720? This code, indicating a “Speed Sensor Circuit Malfunction,” can be frustrating and impact your vehicle’s performance. Let’s delve into what this code means, its potential causes, and how you can troubleshoot it, specifically for your Nissan Maxima.
Code P0720 is triggered when your car’s Powertrain Control Module (PCM) detects an issue with the output speed sensor circuit. This sensor is crucial as it monitors the transmission output shaft speed, providing data necessary for proper gear shifting, speedometer function, and overall transmission control. When the PCM receives incorrect or no signal from this sensor, it sets the P0720 code, often accompanied by noticeable symptoms.
Common symptoms associated with a P0720 code in a Nissan Maxima can include:
- High RPMs with Limited Power: You might notice the engine revving higher than usual when accelerating, but the car struggles to gain speed. This is often described as “RPMs skyrocket, but I hardly get any power to the wheels.”
- Shifting Problems: The transmission may hesitate to shift gears, shift erratically, or fail to shift at all. You might experience difficulty getting the car to “catch” a gear.
- ABS and SLIP Lights: In some cases, the Anti-lock Braking System (ABS) and Slip Indicator lights might illuminate on your dashboard alongside the check engine light.
- Speedometer Malfunction: The speedometer reading may be inaccurate or erratic.
- Other Diagnostic Trouble Codes (DTCs): P0720 can sometimes appear with other codes related to catalytic converter efficiency, such as P0420 and P0430, or other transmission-related codes.
Several factors can contribute to a P0720 code in your Nissan Maxima. Pinpointing the exact cause is essential for effective repair. Potential culprits include:
- Faulty Output Speed Sensor: The sensor itself might be defective due to wear, damage, or electrical malfunction. It’s possible the “Revolution Sensor” mentioned in the original query is indeed the output speed sensor.
- Wiring and Connector Issues: Problems within the wiring harness connected to the speed sensor, such as damaged wires, corrosion, or loose connections, can disrupt the signal and trigger the code.
- PCM/TCM Malfunction: While less common, a fault within the Powertrain Control Module (PCM) or Transmission Control Module (TCM) could misinterpret sensor signals or incorrectly set the P0720 code.
- Mechanical Transmission Problems: In rare cases, internal transmission issues might indirectly affect the speed sensor signal, although this is less likely to be the primary cause of P0720.
Troubleshooting a P0720 code on your Nissan Maxima typically involves a systematic approach:
- Visual Inspection: Begin by visually inspecting the output speed sensor, its wiring, and connectors. Look for any signs of damage, loose connections, or corrosion. Pay close attention to the sensor’s location on the transmission and ensure it is securely mounted.
- OBDII Scan Tool Verification: Use an OBDII scan tool to confirm the presence of the P0720 code and check for any other related DTCs. A scan tool can also be used to clear the code after repairs are made.
- Sensor Testing: If accessible, the output speed sensor can be tested using a multimeter to check for proper resistance and signal output. Refer to your Nissan Maxima repair manual for specific testing procedures and expected values.
- Wiring Circuit Testing: Inspect the wiring harness for continuity and shorts using a multimeter. Check the voltage supply and ground to the sensor to ensure proper electrical flow.
- Sensor Replacement: If the sensor is suspected to be faulty after testing, replacing the output speed sensor is a common next step. Ensure you use a compatible replacement sensor for your Nissan Maxima model.
- Professional Diagnosis: If you are not comfortable performing these diagnostic steps or if the problem persists after sensor replacement, it’s advisable to seek professional diagnosis from a qualified mechanic specializing in Nissan vehicles or transmission repair.
Regarding the user’s question about the “Revolution Sensor” and its relation to the P0720 code, it’s highly likely they are referring to the output speed sensor. Replacing this sensor, as they did previously, might indeed be a solution if the sensor is faulty again. However, it’s crucial to properly diagnose the issue to rule out wiring problems or other underlying causes before simply replacing the sensor again.
In conclusion, encountering a P0720 code on your Nissan Maxima can indicate a range of issues related to the output speed sensor circuit. By understanding the symptoms, potential causes, and troubleshooting steps, you can effectively address this problem and restore your vehicle’s performance. Remember to prioritize safety and consult a professional if you are unsure about any aspect of the diagnosis or repair process.
