Hello all!! My 2004 Express cargo van is approaching 100k miles and has had a frustrating intermittent problem ever since I hit an elk last spring. First the speedometer starts to wiggle. A few seconds later the brake and abs lights come on and 33 chimes start dinging. Sometimes but not always it starts shifting erratically mostly between 2nd and 3rd gears. This continues for a few minutes, goes back to normal and then begins again with the bad shifts getting progressively worse. I've been to 3 different mechanics who all tell me the same thing. "I can't get it to show those symptoms but it seems to be fine now. It shows active codes for the VSS sensor and wheel sensors but I can't proceed since it's not showing the problem." The last time this happened was 2000 miles ago but it just happened again. I tried disconnecting the battery with no results. Wondering if purchasing a code reader would enable me to stop this from happening somehow. Thanks for any advice.

 

Yikes,I would have a multimeter with me and check tranny fuse for battery voltage when problem happens or while monitoring the fuse,start a wire wiggle test,try to introduce it on your terms

 

A code reader is always a good investment.

 

When you hit the elk, did you have the front end repairs done through and insurance company or fix them yourself? IE Is there a repair shop to fall back on?
It sounds like an intermittent electrical issue, ans those are the most fun to find....lol
I agree on the code reader. Have one in the van, and when it happens again, pull over and hook it up to see whats up. Hopefully that will steer you somewhere useful.

 

A new mechanic offered to read and clear my codes for $25. He said there are codes for VSS and transmission but was unable to clear them and to leave the van. He said I probably need an expensive new computer but he needed to spend a few hours for diagnosis. It's 3 weeks until payday so I declined. When i started the van the dash was clear and everything was back to normal. After a few miles, the symptoms returned as before. I've been driving it sparingly around town for a week. It still chimes, with the dash showing ABS and BRAKE with bouncey speedo, sometimes shifts weird and the brake pedal occasionally buzzes. This goes on and then it goes back to normal every few minutes.
​​​​​​I'm surprised he told me that he couldn't clear the codes since it was all good for a while. Wondering if he made that part up so I would leave it with him.
Yesterday all symptoms stopped for the entire day about 10 miles so far. I can buy a code reader after payday but I don't know which one. The cheap ones say they don't clear ABS codes but I'm getting active VSS and transmission according to the last mechanic. It's also shown wheel sensors before.

Should I look for a different mechanic come payday? Can anyone suggest an inexpensive code reader that might be of use? It seems like clearing the codes temporarily stops my symptoms or maybe it's a coincidence since they just spontaneously stopped yesterday. Thanks.

 

Maybe what he meant was that even if he cleared the codes, they would come right back. If it were me, I'd pop the front wheels off and inspect the VSS. Could just be a broken wire.

 

You can start by looking online. Advance Auto Parts or AutoZone carry some as well. AA and AZ usually will read your codes for free. That's why you might want to find another mechanic.

 

I wonder if water / moisture seeping in through a broken electrical seal would cause just enough electrical flow to throw the computer out of whack? My guess is a loose wire too.

 

The VSS on the transmission has been replaced and wiring inspected but I'm not sure if the wheel/abs sensors have been. I got new tires and wheel bearings replaced after hitting the elk 500 miles before the first symptoms. Do my symptoms match with a badly connected wheel sensor?

 

Oops I meant to say inspect wheel speed sensors. A bad sensor would throw ABS out of whack. I don't think the speedo or transmission uses them though.