Calum help on tach problem [Archive] - SR20 Forum

: Calum help on tach problem

07-29-2009, 07:39 AM
Ei I read your articles on tach problems but I cant seem to find the Q457 that I have to replace. I attached pics so you could help me out. I tried checking the voltage for pin 2 which is blue black and it only read .09 Volts. Could you please help me out.

07-29-2009, 07:42 AM

08-03-2009, 07:09 PM
what board is that frm my friend? that board doesnt resemble my b13 board, so im curious as to what vehicle that hails

08-03-2009, 07:52 PM
Im using it in my b13, for my roller rocker. I dont know where it originally came from but Im sure its JDM.

09-01-2009, 11:07 AM
Any idea calum?

09-01-2009, 11:35 AM
I got the tach working but I connected it through the distributor and now Its working fine but now I swapped to a digital cluster gauge and my friends told me that I cant use the signal from the distributor and that I should use the signal from my ecu. Is 0.09volts normal for the ecu tach out? because i read the FSM and it said that I should be getting around 1 to 5 volts. Any help would be appreciated thanks :)

09-03-2009, 10:33 PM

09-04-2009, 12:30 AM
The tach output from the ECU is a pull down, it switches to ground. So you won't see anything unless you put a pull-up to something. The cluster has the pull-up built in.

09-07-2009, 12:27 PM
Thanks a lot for the reply, I really appreciate it bro. Nobody knows anything about ecu problems here in the Philippines so I'm gonna document it in a local Nissan forum here. Ill try connecting the cluster and see if i get anything. Thanks again

09-08-2009, 03:26 AM
I tried connecting the ecu pin for the tach to the digital cluster and nothing happened. I tried getting a voltage and I got nothing too. Without the cluster connected I get around 0.023v. Im trying to look for another ecu I can borrow and then I'll try it again Is there another way to put a pull up without the cluster gauge?

09-10-2009, 06:25 PM
Yes, just wire a 10k resistor from the tach line to +battery.