Is this the AT545 output speed sensor?

[Jesus-SKO]

I ask if this is the AT545 speed sensor because my speedometer and odometer are broken, so I'm trying to locate it. They say it's near the output drive shaft, but it just doesn't look anything like the speed sensor that supposedly comes with my vehicle: https://www.rockauto.com/en/moreinfo.php?pk=669264&cc=3296369&pt=10634&jsn=480. But it's also the only thing near the drive shaft. Could this be it? Thank you!

 

[Jolly Roger bus 223]

that looks like the pressure switch for reverse lights to me.
i think the speedo is actualy a gear on a cable?

 

[nikitis]

I believe that is the speed sensor, it's at the tail end of the transmission coming out as a wire like that, If it's not that then look for another one further towards the smaller end of the transmission similarly protruding like that. It has wires coming out of it as well.

It's supposed to be a rotating magnet on the inside of the spline, and the speed sensor screws into the thinner bell housing area and lines up with that magnet, and it generates an alternate current (low current), and the speed at which that spins helps combined with the number value in the VPM/ECM, which that number represents gear ratio and tire size as a combination, is used in a formula to determine your speed on the speedometer.

On my AT545 transmission it's protruding on the driver side outwards of the transmission.

 

[cadillackid]

thats the speed sensor.. the ones that used a cable were in the same spot..



there were different sensors used based on the vehicle.. its a hall effect sensor.. theres a tone wheel on the tail shaft inside that the sensor picks up..



if you bought a different transmission from an older vehicle and installed the newer style speed sensor then its possible you have a gear on the tailshaft and a sensor screwed in which wont work..



the sensor you posted is an ABS wheel speed sensor.. the sensor on the back of the transmission is for the dashboard speedometer and NOT an ABS system...



depending on the ABS system you have, you have a speed sensor on each wheel or if you have rear ABS only you may have a sensor in the pinion of the rear end...

 

[Jesus-SKO]

Thank you! But are you sure the link I provided is for the ABS wheel speed sensor? Because this is what it shows as the ABS wheel speed sensor: https://www.rockauto.com/en/moreinfo.php?pk=7493264&cc=3296369&pt=1912&jsn=10490

 

[Jesus-SKO]

Thank you! But I'm still unsure... This is what comes up as the ABS wheel speed sensor:

and this is why I thought that part I linked was my dashboard speedometer's speed sensor:

Is there something else I should search for to find it?

 

[cadillackid]

this is the one the AT545 on my 99 chassis uses...


https://www.ebay.com/itm/3647189416...TKBrFqdtGlpvpWCO1O0aMoiJiYDr54mRoC6lQQAvD_BwE


its an IH part number 3522826C91


no clue what the GM part number is.. but my speed sensor is threaded and screws in..



if the sensor you posted isnt a wheel speed sensor its probably a sensor for a Van chassis 4L60E or such.. it looks similar to the sensors i use on my allison 1000 as well..

 

[Booyah45828]

2131151 is for the fuller manual trans that was an option for your bus.

acdelco# 213237 should be for the at545 automatic

 

[Booyah45828]

and yes, your first picture shows the sensor

 

[cadillackid]

2131151 is for the fuller manual trans that was an option for your bus.

acdelco# 213237 should be for the at545 automatic

nice! lot less expensive than the IH part!

 

[nikitis]

The one Cadillackid posted was the one I have in my bus that I replaced. My first repair actually on the bus.

 

[Booyah45828]

nice! lot less expensive than the IH part!

Could very well be the same part. My only concern would be the plugs being different. I can't get a good look at either online to tell for sure.

I'd have confidence using the delco part for a gm bus. Same with the IH part for the IH bus.

 

[cadillackid]

Could very well be the same part. My only concern would be the plugs being different. I can't get a good look at either online to tell for sure.

I'd have confidence using the delco part for a gm bus. Same with the IH part for the IH bus.

true they have subtle differences in connectors.. the IH uses a weather-Pak which I know GM used a lot of too.. but GM also seemed to use Molex on some things that puzzled me over the years..



chrysler tended to use Metri-Pak... but then my red bus has a mixture of Weather-Pak and Metripak..



I guess its a fishbowl of business cards.. draw and go

 

[Jesus-SKO]

Thanks for the clarity, everyone. Before I jump into buying the part, would it be reasonable to disconnect the sensor and then connect an Arduino that will send pulses, in order to see if the speedometer moves? The Arduino's pins give off 5v by default.
And would I need to disconnect the battery before trying this?

 

[nikitis]

Thanks for the clarity, everyone. Before I jump into buying the part, would it be reasonable to disconnect the sensor and then connect an Arduino that will send pulses, in order to see if the speedometer moves? The Arduino's pins give off 5v by default.
And would I need to disconnect the battery before trying this?

An Arduino may not work unless it has oscilloscope capabilities to see the pulses. You could use the existing broken one and tie into the wires to see if it's giving off pulses, you can also use a multimeter to do the same.

 

[Booyah45828]

Thanks for the clarity, everyone. Before I jump into buying the part, would it be reasonable to disconnect the sensor and then connect an Arduino that will send pulses, in order to see if the speedometer moves? The Arduino's pins give off 5v by default.
And would I need to disconnect the battery before trying this?

You can if you want. I wouldn't waste my time.

Check the resistance of the sensor. I think it's a mag pickup and not a hall effect unit, so see if the resistance is within spec. Use google for the spec, I don't have it off the top of my head. The signal created would be just a low voltage ac synchronous wave, and the speedometer will use the frequency to give you a mph reading.

I've got a signal generator that I used once for such a thing like this. Most of the time the problem is easily identified before it gets to that point.