I'm totally stumped and don't know what to do. I'm the original owner of my 2005 TSX. I just replaced my clutch... what a PITA! This was just a straight forward clutch replacement... the transmission was never cracked open and the pick-up / speed sensor was never removed. I get everything back together, take for a drive and the speedometer doesn't work. A couple of miles into the drive and the CEL pops up. I scan it and get P0720 (Countershaft SPD sensor circuit malfunction). I purchased a new sensor (28820-PWR-013) from Honda. When I removed the original sensor to replace it, the tip had broken off inside the transmission (pic attached). I have absolutely no idea how this is even possible. Using a strainer and coffee filters, I drained and filled the tranny 4 times in order to try to flush out the debris from the broken sensor, but nothing came out. I installed a magnetic drain plug with hopes that it will help. I installed the new sensor and cleared the code with the scanner. I take it for a drive, and still no speedometer and the CEL pops up again with P0720. I removed the sensor and again, the tip has broken off inside the transmission again (pic attached). There's obviously some type of interference going on with the sensor, but how this is possible since the transmission was never opened is beyond me. It can't imagine it being a gear alignment issue inside the transmission because it shifts perfectly... even with all the debris now in there. I read on another forum that the sensor comes with 2mm washer, however, the new one did not come with it. I also did not see a washer when I removed the original sensor. Any thoughts or insight you can provide would be greatly appreciated.

 

There absolutely would have been a washer between the transmission case and the shaft speed sensor. For future reference, it is not necessary to remove the VSS when swapping the clutch. Even though the exploded diagram shows that the spacer washer should have come with the new sensor, since it did not, I suggest you order the spacer washer (part number: 90401-RAR-M00 ) and install it with your SECOND new VSS. Continuing to do what you have already done twice will produce the same result... a broken sensor and more parts inside the transmission case that MAY cause internal damage over the long term.

 

There has to be some sort of alignment issue with the tranny where it meets the block or somehow something fell into the tranny somehow. That's really the only explanation since you never removed the sensor. Somehow it's allowing the sensor to get hit by something. I think you know you're going to need to pull the tranny, crack it open and remove the broken pieces unless you want the internals to get damaged too.

 

Thanks! The puzzling part about this is that the sensor was not removed during the clutch install. It was only after everything was put back together, took it for a drive and got the P0720 code that it was removed and found to be broken. Thanks for the part number for the washer... I actually ordered it this morning along with a new sensor. Question... the silver metal cap should remain on the sensor when installed into the tranny, correct?

 

Yes, the silver cap stays on the end of the sensor.

 

The sensor has an airgap that must be maintained.

I would pull the trans and split it. That is the only way to get the debris from the sensor out.

 

 

 

So where did you put the spacer at ? On the screw or on the actual speed sensor? Having the same issue as of rn

 

Between the transmission case and the black tab on the VSS sensor itself... so the bolt passes through the hole in the sensor, through the spacer, and into the threads on the transmission case.

 

Did you end up getting the metal caps out the transmission?if not did u encounter any problems later on,

 

It ain't good for loose parts to bounce around inside the transmission... there are many places where there simply isn't room for large parts to pass between gears and the case... cracks will occur and failures will happen. Open the transmission up and clean any debris out.