esc
Todd King
Todd_King at ccm.co.intel.com
Thu Apr 17 15:57:49 GMT 1997
<<<
Nieghbor came over and wanted help on his 82 Camaro. Local shop told
him that he need a esc module because timing didn't advance. Module is well
over $100 at GM, only source. Check timing and found it advances with or
without module attached. Main symtom appears to be idle varies widely. I
suspected module is for retarding if pinging is sensed. Can anyone help ? The
82 has cross fire injection, all simple tune up items have been done. Car does
pass smog test for calif.
Thanks Vance
>>>
Typically an esc (electr sprk control vs est- electr sprk timing) module is
for knock sensor processing and signalling as you describe. You could check it
by tapping on the block somewhere with a wrench or hammer; if it's working you
should be able to tell somehow that spark is being pulled (I used a scope and
my ears/timing light). At least on the GN's all the esc does is some analog
filtering of the knock sensor, then it pulls the esc signal line to the ECM
low briefly when knock is detected. Keep in mind that the least reliable part
(by far) of any electrical/onic system are the connectors and cables. The esc
line should remain high when knock is not present, again on the GN's but
probably similar for the Camaro. One caveat is that some of the
implementations may have a self test process where the ECM briefly adds timing
until the esc signals knock, then of course pulls timing back to normal. You
should start by pulling the trouble codes and seeing if an esc error code has
been set.
Todd_King at ccm.co.intel.com
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