About 2 years ago i had a problem where the ABS and Brake lights came on and off randomly and some random lose of the speedometer. At the time i did some research and from that research i switch out the rear wheel sensor on the rear differential and the brake switch b/c my truck was throwing a code for the brake switch. After i completed this work everything went back to normal for a while.

A couple of months ago the problem return. I'm trying to figure out what the cause is now.

1) i climbed under the truck and check the wiring harness and connection on the rear differential and found nothing noticeably wrong.
2) i changed the vehicle speed sensor located in the transmission.

i still have the problem: CEL is on, ABS light and Brake light go on and off randomly, and speedometer drops out randomly. when the speedometer drops out i get this noticeable lose in power but if i keep my foot in the same spot on the gas pedal i dont lose speed, but my mile per gallon plummet per my eco meter. i confirmed this at the pump the last two weeks too as i usually get about 12 - 14 MPG and now im getting 7.5 MPG.

3) today i removed the fuse powering the ABS module just to take the module out of the equation. Of course to be expected the ABS light and Brake light stayed on, but while driving my speedometer kept randomly dropping out.

another note: i reset my eco meter and when the speedometer is reading my truck gets normal gas mileage and as soon as it drops out and i lose power it plummets.

CEL is throwing code P0573 but i dont have issue with cruiser control or braking.

 

UPDATE:

I checked my odometer and tripometer while driving today. It seems that while the speedometer isnt working the odometer and tripometer are not ticking the mileage up. so i can assume im not actually losing MPG.

 

I *think* that that speedo gets its cue from the left front wheel speed sensor, but, am not certain of that..... may wanna have codes read, and see what it thinks.

 

i have a cheap code reader but it only gives me that P0573 code as does auto zone when i go there.

i did recently bring my truck in for that air bag recall and they read the code at the dealership. he said the code either read "speed sensor" or "rear speed sensor" i dont remember.

 

A better scanner might be nice here.

That code is for the brake switch, so, I am thinking a separate problem from the speedo.

 

is there a recommended scanner thats good?

ive had this code before and changing the brake switch didnt fix it.

 

Most of the stuff I could recommend don't support trucks that new...... There are various apps you can put on your phone/tablet/laptop, but, so far, aside from the high dollar variants, I am not really impressed with any of them. Basically, you want something that will show you live data. A fair few of them will show you some, but, will it show you what you actually need? That is a mighty big question. The software I got (OBD Wiz) shows me maybe 15 out of a couple hundred prids.... pretty much useless. It reads/erases codes, and that is about it.

We have a discussion about this in the 2nd gen FAQ/DIY forum.... (I think that's the right one.... might be in general discussion....) but, most of the guys running the older trucks just grab a Snap-On MT2500.... which won't work on your truck.