Speedometer intermittently inaccurate even after tsb 10-18-7 was applied

[buckbabes]

Hello Everyone,

Help!! I am checking to see if anyone had experienced an issue where this TSB did not fix their speedometer issues.

I have a 2010 SHO and in December of 2011 I was having an issue were the speedometer would display inaccurate speeds. For example the needle would either point at 10 - 30 mph while at highway speeds or point at 60 while at a complete stop. I brought the car to the dealership and they updated the instrument panel cluster in accordance with TSB 10-18-7. I was under the impression that this update had fixed the issue however, i noticed the problem returned.

on one occasion I was driving to work doing the speed limit (60 MPH) and for some strange reason i was passing cars like i was drivring 90. Feeling that something was wrong, I slowed down to match my speed to what the average motorist was driving. My speedometer was now pointing at 40. I then turned on my cruise control and set it to 60. The speedometer moved slightly but was still pointing at around 40 - 45. to further verify my speedometer was acting up I pulled out my phone and turned on my GPS speedometer app (Ulysse speedometer pro). The app showed that i was traveling at 68MPH. I pulled over, turned the car off and back on and continued down the road the speedometer was now accurate.

Has anyone else who had the TSB performed noticed that the problem returned? or never went away?

and Has anyone figured out how to replicate the speedometer issue on demand rather than having it happen intermittently?

Thanks,
Manny

 

[SHO2k11]

I am currently having this problem. I didn't know about the TSB and had taken it in, the dealer didn't do anything because they couldn't replicate the issue. I has happen to me a few more times in the last year, but i figure there was no sense trying to take it to them because it would replicate when you shut down the car. The last two days that I have taken my car through rush hour commute it has occurred and always on the return trip which is the worst.

Manny have you received any resolution on your deal?

Has anyone else experienced this problem?

If the issue has been documented under warranty, would the dealership honor the issue? My car is currently our of warranty and I really don't want to spend 500$ to replace the instrument panel.

Also, is it possible to to run the ETM (Engineering Test Mode) on our cars?

Thanks

 

[SHO_Fast]

I have had this happen a couple of times, and on at least one of those occasions I know I had started the car and immediately put it in gear, not waiting for the speedo and gauges to swing thru their arcs and back to zero. When I shut the car off and re-started, waiting on the gauges, it was fine. So I have assumed that the speedo was inaccurate because it had not finished calibrating before I drove away. Now I make sure to wait and I have not seen it since.

Anyone else agree with that?

 

[RichInMich]

Never even knew this was an issue - is it just 2010's that are doing it, or has it spread to other years?

 

[markathome]

Not heard of this one either....interesting.