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Code po721 should I just rebuild trans? PO721 how to reset.

Customer Question
Code po721 should I...

Code po721 should I just rebuild trans?

Mechanic's Assistant: Just to clarify, what's the exact code? And have you tried to reset it?

PO721 how to reset

Mechanic's Assistant: What is the model/year of your transmissions?

BMW 325! 2001

Mechanic's Assistant: Are you fixing your vehicle yourself? What have you tried so far?

Nothing I was going to try but I was reading another post with same code on this site

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

Where the sensor loction

Submitted: 8 months ago.Category: Transmissions
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Answered in 6 minutes by:
11/14/2017
Transmission Mechanic: Pete, Automotive Mechanic replied 8 months ago
Pete
Pete, Automotive Mechanic
Category: Transmissions
Satisfied Customers: 33,012
Experience: GM and Mercedes vehicle technician.17 years experience.
Verified

Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.

If you did not replace the output speed sensor I would have this done first.I would also make sure wiring to the sensor is o.k. as well.If the code returns ( after you have it cleared with a compatible scan tool as this is the only way to reset it) then you will need to have the transmission looked into further to locate the cause for the speed sensor code.It is possible there is a mechanical fault in the transmission causing this code to set like worn gears or components or a damaged gear but the sensor being replaced most likely will correct this issue.Below is the location of this sensor with the pan removed on the A5S 325Z transmission.

https://www.dropbox.com/s/p4ro0v5o01z7ab4/se-11-14.gif?dl=0

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service,your 5 star rating is appreciated ( should be a link to click on here or above).You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete

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Pete, Automotive Mechanic
Category: Transmissions
Satisfied Customers: 33,012
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