Could the P0720 fault code in my 2002 Dodge Ram 2500 with a V10 engine and automatic transmission be triggered by installing oversized tires? I've noticed the vehicle is throwing a P0720 code, which indicates an output speed sensor circuit malfunction—potentially due to wiring, connector issues, or a faulty sensor itself. Is tire size adjustment relevant here?
It's unlikely that oversized tires alone would trigger the P0720 code. This fault is more commonly caused by electrical problems such as intermittent wiring, open or shorted ground or signal circuits in the output speed sensor. Key troubleshooting steps include verifying that tire size has been properly reset in the Powertrain Control Module (PCM). Ensure all four tires are identical and match the factory specifications. Common causes: - Intermittent wiring and connectors - Output speed sensor ground circuit open - Output speed sensor signal circuit open - Output speed sensor ground circuit short to ground - Output speed sensor signal circuit short to ground - Output speed sensor ground circuit short to voltage - Output speed sensor signal circuit short to voltage - Faulty output speed sensor
How do I reset the tire size in the PCM? My current tires are 355/65/R18, while the factory-recommended size is 245/65/R16. Does this mismatch require a specific procedure?
You'll need to use an OBD-II scanner to access and update the PCM tire size settings—many tire installers or auto shops can perform this service. Note: The 355/65/R18 tire size may be outside the manufacturer's recommended range; verify compatibility with your vehicle’s specifications before installation.
While oversized tires can affect vehicle dynamics and speedometer accuracy, they are not typically the direct cause of a P0720 code. The P0720 code specifically points to an output speed sensor circuit malfunction—this could stem from wiring issues, damaged connectors, or a faulty sensor.