PO722

[mrbort]

Hey Everyone,

I've got a 98 Jetta MK3 2.0 automatic. Check engine light came on and i pulled the code PO722 for no signal on the output shaft speed sensor. The car runs but it has trouble shifting from 3rd to 4th. It revs really high before i can finally get it to shift. Can someone tell me where this sensor is located? I'm going to attempt to replace it today. Thanks in advance for any help you can give me.

Scott

[mrbort]

help. i can't find this thing.

[le0n]

just taking a guess that this is your crank position sensor, so it should be located near your main pulley...

edit (the following was stolen from vortex):
Kinda hard to do diagnostics on a car without a VOM (Volt Ohm Meter) You can get one at Walmart or any car parts store for around 10 bucks.

If you can't, pull the sensor and do the trick I described.

The easiest way to pull the sensor:

1. Jack up car and use jackstands. Disconnect battery!
2. Support motor near transmission bell housing with jack. Put a little pressure on it.
3. Unbolt front motor mount. Two bolts go through starter. Pull starter and set to the side. No need to disconnect wires.
4. Unbolt Main Allen type bolt going through round part of motor mount. (Bottom side)
5. Remove both the rubber and metal mounts. It's tricky, but if you turn it on it's side you can maneuver it out.
6. A few people say to remove the oil filter. I didn't fint it necessary.
7. Unplug sensor from harness, follow the wire back and pull the clip securing it to the block. It's a pull type.
8. Use a 6mm ball end Allen Wrench to unscrew the bolt from the sensor in the block.

You have to pull the motor mount because the sensor is located right behind it. Unless you have tiny hands and a bendable allen. LOL

That's about it.


Modified by 83_WabbitGTI at 8:17 AM 2-19-2010

[mrbort]

thanks Leon i appreciate it.

[le0n]

no problem. i am in no way familiar with that engine, however, maybe you can find it with that bit of information...

[mrbort]

I'm hoping that i described the correct sensor. I had heard that it was located on the top of the transmission. I'm such a noob at this stuff. I'm probably better off just taking this to a professional to have it done. I'm probably out of my league on this one.

[le0n]

^^ you are correct (i was mistaken). further googling (while at work) shows this sensor to be for the transmission.

read this thread for a better explanation of what could be happening: http://forums.vwvortex.com/showthrea...e-Speed-Sensor

[DonJuan1Jr]

Look on the trans itself for a two pin sensor...when i get home I can snap a pic of where it is. Usually its on top.

[mrbort]

yep thats it! the limp mode is exactly what is happening where it doesnt shift until i hit 4000 RPM. This is great information and extremely helpful! Thanks for finding this for me. It's also comforting to know that I actually ordered the correct part too. haha. Don would you mind snapping a pic of it when you get home and posting it on here? I'll let you know how it goes with an update as soon as I attempt this. Sounds like it can't be that hard to do. It's also pretty apparent that i should get a Bentley manual since the Haynes manual I have doesn't help at all with this issue (that i could find anyway).

Scott

[mrbort]

Success! Just replaced the sensor and the car is running great again. Thanks for the help guys! It wasn't as bad as I thought it would be.

Scott

[le0n]

congrats and thanks for the update...

[DonJuan1Jr]

ahh great its fixed cuz im completely forgot to pop the hood.