99blancoSS

iTrader: (115)

My car has an issue somewhere with the electrical. The VSS when logged reads 30 mph at idle and the speedo shows 0 mph. Car is sitting still in driveway idling when VSS is showing 30 mph.

JMBLOWNWS6

iTrader: (17)

It could be a bad VSS. I had this problem on a car but it was the opposite. The speedo would not read and the VSS was picking up. Ended up being the pin from the VSS to cluster had a open connection. I would unplug the vss and log it. To see if you get a reading at all.

99blancoSS

iTrader: (115)

right on! this is driving me nuts. Its not the only issue, IAT and Coolant read -41 before car starts as well and the wavelengths of more than a couple sensor signals are the same. I was originally thinking ground so I regrounded the pcm but to no avail.

comment from other board
Can if be buggered up to the point its bringing down the other sensors?

I also have the same misfire counts for cylinders 6 7 and 8.

99blancoSS

iTrader: (115)

Ok, unplugged both plugs at end of trans and still says 30mph. WTF?
Can the ecm be hosed but still run the car? First time I logged it didnt have the strange misfires but I wasnt logging the vss at the time so I'm not sure about it. I then reflashed the ecm with a different tune and the misfires counts began but only on 6, 7 and 8. Sp I did a crank re-learn and the misfires went to all cylinders. Did another and it returned to just 6,7 and 8.

Could something have happened in the flashing to have popped something in the ecm? My TPS signal is all over the place as well with the car running. I cant plot it just fine with the engine off. But my temp sensors read -41 with the engine off and climb to within like 10-20 degree of actual temp with the car running.

cantdrv65

iTrader: (3)

Reflash the PCM with an old tune....if that fixes it reflash again with the new tune. My vette PCM does the same thing when I reflash the calibration with EFI live every once in a while and another reflash always clears it up. Sometimes it takes flashing an old tune back in first though....Don't ask me why???? Each time it happens the display will freeze, sometimes none of the gauges work but the car seems to run fine.

99blancoSS

iTrader: (115)

I've tried it a couple times. To no avail. I will look at the harness again tomorrow and trace the tps. I have a road runner sitting here so I can swap the ecm but I dont want to put it in if something is going to happen to it. IF there is a short somewhere but I swear I introduced the misfires by flashing the ecm when I did the IFR and MAF table. The misfires were like 7 or 8 or 9 per cylinder and I flashed it with the new tune and that when the misfires counts went haywire on cyls #6,7,8

cantdrv65

iTrader: (3)

You tried loading in an OLD tune? If so, I'd also try to flash the entire 512K back to stock, not just the 96K calibration. The try the new cal again.

LS1curious

Before you go chasing your *** in cirlces. try a factory approaved scan tool like a Tech II or a SNAP on or OTC genysis. Could be a problem with your logger software.

edcmat-l1

iTrader: (10)

That happens to me every once in a while. Just flashing it again with the cal seems to fix it. No particular reasoning, it just wont have any dash activity, reflash it and its cured.

LS1curious

At the end of the write cycle the software for the programming utility sends a wakeup command for the modules on the data bus. If they are unresponsive or the software does not send the command then the dash will freeze up. I thought all the software suppliers had pretty much fixed this by putting in a wake up response resend command setup at the end of the ultility program.

99blancoSS

iTrader: (115)

I tried re-flashing to several previous tunes but to no avail. I may have had a power interrupt while I was flashing and that may have something to do with it as well. Laptop died in the middle, then I plugged it in and I cant remember what state the flash was in. I rebooted the pc and then flashed it all over again. It seemd to flash ok but maybe this is the result?

I will disconnect the power and see if that somehow resets the ecu. If it doesnt then I will check the TPS wireing again. I've had p0121 codes for a long time. I I cant find anything I'll install the Road Runner and flash it with my tune and see if it persists.

LS1curious

Have you tried a different scan tool yet ?

99blancoSS

iTrader: (115)

No, I dont have a different one available to me at this time. I replaced the battery with a new one (other one was still on warranty I told them it wouldn't hold a charge). The check and saw 12 volts but only 28 amps, swapped it for a new one.
I'll do a full relfash. I havent done one yet and then see what comes up.

99blancoSS

iTrader: (115)

Ok swapped the battery and did a full reflash and still the same.

cantdrv65

iTrader: (3)

Any luck? Did you try the roadrunner?

cantdrv65

iTrader: (3)

Hmmm. I haven't updated the EFIlive software on my laptop since....well NEVER. Its two years old....I guess I may want to do this!