Hi all,

During my troubleshooting on a completely unrelated issue, I accidentally disconnected the wire to the VSS on my '97 Grand Prix. I reconnected it, and went on to something else.

Once I had my wheels back on I drove, like normal, for a good 20 or so km. Out of nowhere, my engine started to surge, tranny stopped shifting, got an engine light and the speedometer went dead. Confirmed with my OBD-II scanner, I got a code of P0502, Vehicle Speed Sensor (VSS) Circuit Low
Input.

I thought the cable got loose so I pulled the front passenger wheel off and checked; it was still on. I reseated the connection and took a short test drive. Things were working fine for about 10 minutes, then back to having a dead speedo and no shifting. The drive home was long, with intermittent working of the sensor.

That was last night. This afternoon I just finished unhooking the connector, spraying the pins on the connector and sensor with electrical cleaner, and reassembling.

Did a test drive and within 2.5 km the speedo went dead and I lost shifting.

I'm really wishing I hadn't even touched that connector The car has never had this issue before. I don't think it's the sensor because it does work, at least for a while after a reseat. The wiring is also unlikely for the same reason.

Am I missing something?