ESC Relay

[Buicksandrail]

Upon performing more research and looking at old threads, it appears that the ESC relay inhibits the system on start only. The relay opens up the TCC ground during cranking. Are there any problems with having the system active during cranking? If the relay failed it seems that system would be active even during cranking. Perhaps an active ESC system during start would pick up noise and interpret it as knock and try to retard timing resulting in a no start condition.

Any thoughths out there?

Thanks,

Trent

 

[b4black]

The ESC on my '83 is the newer peizo element like the 84/87 SFI/Turbo use. It is supposed to be more selective to the sounds it hears (less false signals). Even so, it picks up enough "knock" to set the warning buzzer I installed off.

I think your right that the ESC will hear knock and retard the timing during start-up.

 

[84ZZ4]

FYI, my 84 Camaro has a similar setup with no relay. Using a scan tool, you can see it picking up knock counts when the starter is cranked. It doesn't seem to cause problems starting though, I wonder why?

 

[b4black]

Does your camaro have an ECM? If so, the ESC keeps reading knock, but the ECM ignores it during start up. Early ESCs didn't have ECMs to control timing so the ESC needed to be disabled.

 

[Peter]

Yes, the relay does inhibit the ESC during cranking.

I had the relay fry in the "ESC connected" position in my 78, and replaced it with an after market unit. I could not tell any difference in the starting performance!