spedo

Hey guys last night I was driving down the pass and my spedometer started goin crazy. my first thought was somthing was shorting out beacuse it was raining so hard there was standing water every where. and now my spedometer works on and off.
What are your thoughts on this?

 

Our trucks use cables...correct? If it's a cable, then the water probably shouldn't affect it. Maybe it's just going out.

 

I don't know about earlier models, but from 2001 on, Tacoma's have electronic speedometers. It could be a poor connection at the speed sensor or the sensor itself could be failing. It could also be a poor connection at the IC,a failure of the IC printed circuit board or a bad speedometer head. I would check the connection at the transmission speed sensor first and if that doesn't help pull the IC and check those connections. If you have access to a scan tool you can use it to see how fast the ECM thinks the truck is going. Here is the wiring diagram for the speedometer circuit.
Hope this Helps

 

As a side note, is there a way to adjust the speedo on a 2003? Mine seems to read slow.

Thanks,

Flash

 

Do you have a tach in your dash? Is it behaving erratically too? What about the odometer? From '98 on, the data to the dash is all electronic. Fly by wire. No rotating cable any more.

Because there is no cable, there is no way to correct for error.

 

Couldn't you actually adjust with a scangauge or something by "altering" your tire size factor?

 

The ScanGauge does allow the user to add or subtract an "adjustment" (a percentage) to compensate the results it displays. You would have to know how much the speedometer is off, then input that into the SC as a percent change number.

For instance, going from a 31" diameter tire to a 32" is about a 5% change (in revolutions/mile).


from the online tire size calculator

I used this example because it is what was true for my situation. In my case, what was interesting is that after going to 32"s, the Garmin GPS showed my speedo was reading exactly what the GPS said for speed. What this indicates is that the speedo was under reporting from the factory with the stock wheel/tire combo.

I have since read that stock speedometers are allowed to be under by up to 5% but not over.

 

where the hell is the speed sensor on the tranny? cant find it

 

Right hand side of the x-fer case

looks like this:


IMG_0062.JPG by Starwind 19, on Flickr

 

though that was it. THANK YOU

 

Just a suggestion, but if it needs to be replaced, I would highly recommend replacing it with a genuine Toyota.

Just my experience, I replaced (in a pinch) the reverse light switch and bought one from Advance Auto and it wouldn't work. It was dimensional wrong and wouldn't work. Thankfully I had already ordered one online and didn't have to wait long. I was in a big hurry for it because my bass boat has trailer brakes and it needs to receive a signal (via reverse lights) to disengage the brakes when backing up.

 

X2

 

the code my truck is displaying is the speed sensor A, Does that mean there are two sensors?