I'm trying to get my tach signal to be correct for a window switch. Its currently hooked up the the white wire of the ICM. It displays half the value of RPM it should. For instance it shows 500 when it should be 1000. This is with the window switch set on 4cyl. There is no 2cyl mode which I know would correct it if there was. There is only 4, 6, and 8cly. The 6 and 8 throw it off even more of course. Its a 2000 LD9. Is there any other wire IN THE ENGINE BAY or maybe BCM I can tap into to give the correct value? I have tried the purple/white wire and pink wire on the ICM with no luck. I'd prefect not to tap into anything at the ECU (I know pin 10 should work there) due to accessibility restrictions on my setup. So again, is there anything known that I can tap into in the engine bay or BCM that would have he correct value? Also would like to avoid using a tach adapter.



12.6 @ 114.6 MPH

i would say check your ground and make sure it is coming from the same source as your signal


RIP Cpl Derek Kerns And Cpl Robby Reyes
24th MEU VMM-261 (REIN) V22 Crewchiefs
11 April 2012 Morocco (African Lion)

Either need something that reads 2cyl, or you need a tach adapter. No way around it.





i find it amusing that SHOoff has nothing better to do but follow me around & be an unhelpful dick in even cross-forum. - Jon Mick

I ran a wire to a empty pin at the ECU. Before that I was using pink wire on the IDI plug and it gave correct value, but at times would act funny. Since going to the ecu all issues are gone.



FU Tuning

I have used the pink wire at the icm, but pinning it to the PCM is better. The 2000 wiring is posted in the tuning section here.




PRND321 Till I DIE
Old Motor: 160whp & 152ft/lbs, 1/4 Mile 15.4 @88.2
M45 + LD9 + 4T40-E, GO GO GO