Replaced VSS but Speedometer and ABS still not working

Let me start from the beginning here. A few months back I went to start my truck (99 Ram 1500 318 Automatic trans) but didn't hold the key long enough so I went to turn it again, it turned very slow and labored and started with a preignition sound (spark knock) Immediately my ABS and Brake light came on and the speedometer stopped working except at highway speeds. I googled this group and found several entries saying to replace the VSS that connects to the bottom of the transmission. I waited a month or so and my check engine light came on. I took the truck to Autozone for a free scan and it came up that the vehicle speed sensor had failed. It was only $20 so I bought it. I pulled the old one out and found a metallic slime on the end which I guess is to be expected for a strong magnet. The new one went in fine. I pulled the battery cable for several minutes and then restarted.

The truck started and immediately shut off. So I started it again and it came on, but the ABS and Brake light were still stuck on. So I thought well, maybe the truck needs to relearn so I went to drive it. For the first 5 to 10 minutes the shifting was really erratic. Such as waiting till about 3500RPM to shift into second gear even at gradual accelleration. Or sudden downshifting even during accelleration. After

10 minutes the problem seemed to resolve itself.

But I'm still stuck with the original problem. I thought about returning the VSS to Autozone but when I looked at the new one, the plastic has some gouges from my pliers so I guess I'm stuck with it.

Is there any other procedures to reset the ABS system other than pulling the battery? I even pulled the ABS fuses to see if that helped but it didn't. Is the VSS the only part of the truck that feeds the speedometer? I noticed there is another sensor on the differential that is held in with a bracket that also holds some brake lines. I called the dealer and confirmed it was part of the ABS system, they said 50$ for that part and $150 to install it.

Any other suggestions?

Reply to
nightwolf1000
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Uh oh.... you replaced the wrong sensor. It sounds like you replaced the transmission speed sensor, which was NOT the problem. The problem is a bad sensor on the rear differential. That's the sensor that the ABS reads, and where your speedometer signal comes from.

Yep - buy the correct sensor (the one that goes in the rear differential), and replace that one ($150? They're out of their minds - it's one bolt and takes 5 minutes).

Reply to
Tom Lawrence

So is $50 about average, is this something that the average auto parts store would have or would the dealer be the only place?

Reply to
nightwolf1000

$50 seem high... MSRP shows $39.95, with this dealer selling it for $31:

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I don't think you'll find this aftermarket - tends to be a dealer-only item. It won't hurt to try, though...

Reply to
Tom Lawrence

I paid $54 at a dealer in Memphis last summer. Took less than 20 minutes to replace it. Getting the old one out will be a bear, but the new one goes in easy.

Reply to
Greg Surratt

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