C5 speedo/tach jumping as if shorted!!
C5 speedo/tach jumping as if shorted!! Completed a LS2 402 swap ,everything is pretty good, tuning coming along, except the tach and speedo are jumping as if shorted quickly at random times, and it seems to be increasing in occurence.
Also, blew #22 fuse(Injr #1) once since initial startup, but has not occurred again in 20mi of driving. 60 total miles since 1st startup.
Does the injector #1 circuit have a relationship to the speedo/tach connections? Any ideas? Thanks!
Also, blew #22 fuse(Injr #1) once since initial startup, but has not occurred again in 20mi of driving. 60 total miles since 1st startup.
Does the injector #1 circuit have a relationship to the speedo/tach connections? Any ideas? Thanks!
Teching In
Joined: Jul 2006
Posts: 47
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I just had a similar problem. Check your ground to frame. If that is not bad, sounds like a PCM problem, or a BCM problem. Try to re-flash back to stock tune, and erase any problem codes in the PCM/DIC and then re-flash to your current tune. I have a Predator, and there have been times when the file was successfully uploaded, but the oil pressure, and tach were in operative. I reflashed back to stock, then reflashed back to my other and tune and that solved the problem. Also see if your battery is leaking onto your BCM on the passenger side. If it is, you'll likely need a new BCM. If none of this helps, get a loan and take it to a dealer. My last visit was over $1000 for a similar problem. Hope that isn't what you have to end up doing. Good luck!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Mike Fesi 
I had this problem as well.
I found the ground on passenger side head was loose.
ALSO make sure the ground on the driver's side head is good also.
They can both cause you little glitches like this.
I found the ground on passenger side head was loose.
ALSO make sure the ground on the driver's side head is good also.
They can both cause you little glitches like this.
