GenVibe - Community for Pontiac Vibe Enthusiasts

I just installed a motor and transmission from my daughters 2005 Vibe that she wrecked (low miles) into another 2005 Vibe that I picked up. After completing the install, it started right up and ran great with no check engine light, or any other warning lights. On the first drive I experienced an issue with the speedometer dropping a few miles per hour, then returning to the correct speed. It did this every few seconds and the car surged when it did it. I noticed that the new motor had a VSS sensor on the transmission and the old one did not. I replaced the ECM from the wrecked car into the new car since it matched the drivetrain. The same result except it was a longer time between fluctuations. Still no warning lights or check engine light. The car has ASB and the old one did not. Any ideas where I go from here? Thanks in advance for any help!

Welcome to genvibe, and congrats on keeping one of the vibes on the road.

So driving along, the speedo drops a few, and when it jumps back up you feel the car accelerate, or the engine speed goes up when the mph drops?

My first guess would be that something in the transaxle is slipping and grabbing, but I don't know why or if that fits the symptoms. Does the tranny have enough fluid?

Thanks for responding. When it drops the motor surges down not up, so I don't believe it is slipping. It shifts firmly, but not overly, as it goes up the gears. The fluid is right on the marks.

I solved the problem! The VSS on the transmission was fighting the ABS speed sensor for control. I unplugged the VSS on the transmission and everything is working perfectly!!!!

Sweet! That is the best repair, easy and didn't cost. Congrats on the nice solution find

One of the most inconvenient things that can happen to your Vibe is when the speedometer stops working. You don’t really realize how much you look at the thing until it’s just always sitting at 0 MPH while driving down the road.
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