Anyone successfully learned the tach with a Viper 5901 or equivilant? Which wire did you use?

I'm using coil #1 signal off the ECU and the darned thing won't learn it.

I also tried flipping the jumper on the back of the alarm brain according to the docs (required for some vehicles) but it still won't learn it.

So I'm stuck using virtual tach which works OK for regular old remote start but doesn't allow proper valet operation.

Thanks in advance.

 

I used the tach wire just fine for my Clifford 3.3 (same as the viper 5701) and have no problem. I don't know which coil number it was, but I believe it was the yellow wire going into the coil back.

 

if you look at all the coils... you'll notice that there is one common coloured wire... go to one that is NOT common

 

+1. Looks like on my 2004, the White with blue stripe is the common color between all the ignition coil. So go to the NOT white with blue stripe wire. On coil #1, the correct wire was Yellow with Red stripe.

 

I used the same wire (YELLOW/RED) at the ECU (pin #62) rather than at the coil itself to save running wire through firewall. Service manual confirms this should be the right wire.

I further verified there is AC on the wire that changes with RPM using my test probe.

When I hold down the valet button after starting it nothing happens...

 

have you changed the threshold setting on the brain?

 

Yes, I tried both positions for the threshold jumper.

Is this the same wire that is known to work on a 5901?