2006 Jetta 2.5L Automatic: Output Speed Sensor Circuit Fault - Check Engine Light Persistent After Replacement
I own a 2006 Jetta with a 2.5L engine and automatic transmission. The check engine light has been on for some time, and after having it scanned by three different mechanics, they all identified the issue as the output speed sensor circuit — located inside the transmission. I recently purchased a new output speed sensor from a Volkswagen dealership and had it installed by one of these mechanics. However, after the replacement, the check engine light remains on, and the scan still shows 'Output Speed Sensor Circuit' fault. Worse, the transmission shifting behavior has actually gotten worse. Could this be due to a faulty installation or an underlying wiring/circuit issue? Any insights or troubleshooting steps would be greatly appreciated.
It's important to verify the sensor circuit itself — check for continuity, grounding issues, and proper signal transmission. A specialized auto electrical shop can perform a detailed diagnostic on the wiring harness and connections.