HELP!! Did throttle body sync, now tach not working! HELP!!

[Sabre]

I have a buyer coming for my '05 Girly (sniff), and wanted to get it all spruced up for him.

I did a throttle body sync with the tank resting on a work stand next to the bike. All went as it should. Put it all back together, no problems encountered. It runs perfectly, but the tach needle doesn't move. Odometer and all guage lights function, everything functions EXCEPT the tach needle.

HELP! I've checked all the connections I can, from the tach itself back to the ECU. Didn't take the Girly's fairing off to do the work. It all seems in order and I don't think that anything I unplugged for the TB sync would do this. The crank positions sensor shouldn't have died, right? Would the engine even run nicely if it had? How do I check that if that's a likely culprit?

Of course, the check engine light is on from doing the work, and I can reset that with a code reader that I will borrow. That wouldn't make the tach sit at zero would it?

HELP!

[Bixxer Bob]

I've checked all the connections I can, from the tach itself back to the ECU. Didn't take the Girly's fairing off to do the work. It all seems in order and I don't think that anything I unplugged for the TB sync would do this. The crank positions sensor shouldn't have died, right? Would the engine even run nicely if it had? How do I check that if that's a likely culprit? won't be crank sensor, engine wouldn't run if it was
Of course, the check engine light is on from doing the work, and I can reset that with a code reader that I will borrow. read the fault codes before clearing them, it might tell you something

Tacho gets a voltage supply it shares with other instruments, and a signal from the ECU and has a ground connection.  You must have disturbed something whilst you had it apart, think hard....    

If you download Tune ECU and have an OBD cable, you can cycle the tacho and you can see if TuneECU shows a tacho output (soft rev counter on the 'puter screen).

[Sabre]

Thanks so much for the response. I have the missus borrowing a code reader while I'm at work today. I am hoping that the OBD cable from the reader will allow me to connect to a laptop for TuneECU. If not, I'm back at square one.

I'm puzzled by this as the only electrical connections that had to be broken for the TB sync were the battery itself, the fuel pump, the tank guage, and the sensor on the airbox. It looks like the tach wires in question are buried amidst the big bundle as part of the loom passing through this region. What could come apart?

Thanks again!

[Bixxer Bob]

I've been puzzling over this one on and off all day.  I can't think of anything you could have done that would cause this either.

Let's wait and see what the codes throw up.  Whilst you're on though, have a quick look under your ECU and make sure there's no corrosion or water ingress and check the ECU plugs for corrosion as well.  Be careful with the pins, they're small and can bend easy if you're at all heavy handed.

[Sabre]

OK, just read the codes. Intake air temp, fuel level sensor and that's it! No, the OBD cable won't mate to my laptop, so no TuneECU possibility. Cleared the codes, still same problem. Double-checked all connections I can think of, including ECU. All good that I can see.

I'm stuck!

[Mustang]

check all your fuses....................

[Sabre]

Nope, there are no fuses that are soley for the tach.

Saw a similar story from a guy with a 955i Daytona. Followed his advice to simply take it out and run it up to temp and voila! Apparently the ECU is happy now.

Thanks all!

Mysterious beasties, these....

[Bixxer Bob]

That just doesn't make sense  :roll:

Glad it worked though.... :lol: