new problem with speedo

[haulinit]

So I'm still fighting the idle and P0300 codes, but I have a new one. Not really a major problem but more of peeve. The speedo upon key off keeps heading for the 100 mph mark. It made several attempts but it finally did it tonight, I had to drive for a while and once I hit about 40 mph it finally came back. Does anybody have an idea why its doing this?:confused:

[ScarabEpic22]

That could be the stepper motor going out, I know on the TrailBlazers it just locks in 1 position and you have to pull the cluster apart and replace the motor. They cost like 5 bucks off eBay.

[haulinit]

The stepper motors usually don't go bad on something as old as mine. It didnt start doing this till after the 411 pcm swap.

[ScarabEpic22]

Didnt realize you have an 0411 conversion. Post your tune up, it probably has something to do with the System -> Tach section and the tacho pulses. Does the speedo work at all or not?

[haulinit]

The speedo did it again on the way home from work.

[ScarabEpic22]

Hmmm, looks like you've set it up how I would imagine for a 4.3, have you tried leaving it like the factory Vette cal (G1204 and G1205 set to 6) and maybe the B5402 set to No. Im just throwing ideas out there, if you've tried them before my bad.

[Taz]

The Tach settings (G1204, G1205, and B5402) in the current tune are correct for the low resolution CKP used by the 5.7 L Gen I Vortec engine.

Don’t know what the problem with the speedometer is - never had one act like that.


Regards,
Taz

[ScarabEpic22]

OK, thanks Taz for the update.

No ideas then, do you have access to another cluster to check and see if it is the actual cluster?

[haulinit]

Nope no access to another cluster. Wonder if it is another wiring issue? It doesn't do it every time only some times.