MOHFpro90

iTrader: (11)

My tach reads 0 rpm all the time and I cant figure out why. I tried a new tach, no avail. I have one code: IACV (I am not running one, due to the temporary 00vi setup).

Any ideas?

Kevlo911

iTrader: (36)

Check ECU pin5.

G4nismo

iTrader: (9)

check power supply b/t terminal 41 and ground on M84 connector.
if not good, check fuse #13 in fuse block

check ground for the tach. continuity should exist b/t terminal 31 and ground on M83 connector.

check for voltage change b/t terminal 17 and 31 @ idle and 2000rpm(just guestamate).
voltage should change w/ rpm, higher rpm-higher voltage.

also, like kevlo said, check pin #5 of ecu. w/ the engine running at idle, voltage should be around 7V b/t pin5 and ground (#25 is eccs ground)

MOHFpro90

iTrader: (11)

Thanks a bunch guys. I found this in the FSM right after I posted... -.- Anyhow, ill let you know how it goes.

G4nismo

iTrader: (9)

yeh, kinda surprised you would post something like this cause i know you gotta have the FSM

MOHFpro90

iTrader: (11)

Yeah well, after reading that part of the FSM, it basically said I have a bad ground, bad tach or bad ECM.

Seeing that the tach just stopped working one day(it worked when I turned the car off, next time I turned it on it read 0) I guestimated it wasnt a bad ground. And its not the tach itself. So that leaves the ECM, which I dont think would only have this one issue with it...

Thats why I was asking if there were any other possible causes. But I will run through the checklist to see if anything comes up (i.e. short, ground etc).

Kevlo911

iTrader: (36)

Got any friends with a spare cluster?

MOHFpro90

iTrader: (11)

I has a spare cluster


But it has no speedo. Would this affect the the tach at all?

Kevlo911

iTrader: (36)

Nope, infact you can swap out the tach, it is held in by 4-5 signal screws and that's it.

pmohr

iTrader: (26)

Actually, I believe he already tried that.

I still vote checking continuity from the cluster back to the ECU.

Got me all worked up in PM and it's taking forever

Kevlo911

iTrader: (36)

Oh, then try to force ground it and run a wire from ecu

G4nismo

iTrader: (9)

did you tamper w/ the ecu lately? maybe one of the wires loosened (relevant to the tach)
out from the HS. dunno, tell us what you find

MOHFpro90

iTrader: (11)

Omfg.


I swear. I hate this 00VI. The RPM switch, SOMEHOW, was causing the tach signal to read 0.010 - 0.011 V the whole time through the rpms. I disconnected it, and voila!

I mean, seriously...I used a wire tap to tap the thing. WTF

G4nismo

iTrader: (9)

to which source did you have the rpm switch hooked up?

MOHFpro90

iTrader: (11)

The #5 wire in the ECM harness...basically, I tapped the wire from the ECM to the tach.

G4nismo

iTrader: (9)

well i have my switch tapped into the ecu as well as the suprastick w/ no issues

MOHFpro90

iTrader: (11)

I think my Summit itself may have shorted. I am going to investigate it a little more.

The Wizard

iTrader: (43)

MEVI + Harlan switch FTW lol

G4nismo

iTrader: (9)

00vi + MSD digital switch >>>>> mevi + harlan
true story


DO IT wiz! you gainz moar powers!

pmohr

iTrader: (26)

USIM + [blank] FTW!

G4nismo

iTrader: (9)

Ha, i lol'ed a little

MOHFpro90

iTrader: (11)

Dont Lie. You didnt.

pmohr

iTrader: (26)

MOHFpro90

iTrader: (11)

Oh right now, I think USIM might be less frustrating than this thing...