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Was just driving home after an eat out with the wife, I left a stop light and got on it a little bit, maybe half three quarter throttle. When it shifted into third it bogged down quite a bit, and my service engine light came on.

I pulled the code, 43, electronic spark control. What is that telling me. Is there something I need to do, or can I just reset the computer and see what happens. Car ran fine the rest of the way home.

Appreciate any help.
 

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More questions than answers. I see by your modification list you've changed the noise signature of your engine. Two questions come to mind. Have you made any engine mods lately, or messed with the knock sensor connection? I'm just curious if you have a marginal connection at the knock sensor, or if you had a brief instance of false knock, and the ecm noticed that retarding the spark did not eliminate the retard request from the ESC module.
Like I said, more questions than answers.
 

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Found this on an old thread here ...

A CODE 42 means the ECM has seen an OPEN or SHORT to GND in the EST or bypass circuits. If you are not in EST mode after 400 rpms, you engine will feel sluggish with lack of power.

When the SYS is running on the IGN module (no voltage to the bypass line), the IGN module grounds the EST signal. The ECM expects to see NO voltage on the EST line. If there is voltage, CODE 42 sets and will not go into EST mode.

When EST rpm is reached (about 400rpm), and bypass voltage applied, EST should no longer be grounded in IGN mode, so EST voltage will vary.

If the bypass line is OPEN or GND, the IGN module will NOT switch to EST mode so the EST voltage is low and CODE 42 sets.

If the EST line is grounded, the IGN module will switch to EST mode but because the line is GND, there will be NO EST signal and CODE 42 sets. A MEM-CAL not fully seated in the ECM can also result in a CODE 42.

Diagnosis-Intermittent Symptoms
Preliminary
No stored DTC's or DTC stored but no SES light

ECM grounds clean & tight
Air leaks at TB mount and intake manifold
IGN wires for cracks, hardness, routing, and carbon tracking (arc).
Wiring for proper connections, pinches, cuts
Vacuum hoses for splits, kinks, connections (shown on Vehicle Emissions Control Information Label)

CHECK:
Air filter
Restricted fuel filter, contaminated fuel, or improper fuel pressure (34 to 47 psi controlled at the regulator).
ECM GND clean/tight
EGR operation (for being partially OPEN all the time)
IGN timing (Vehicle Emissions Control Information Label)
Exhaust SYS for restriction (damaged pipes, muffler, plugged CAT)
Generator output voltage (9-16v)
Valve timing and compression
ENG for worn camshaft
Secondary voltage (oscilloscope or spark tester)
Excessive retarded IGN timing (EST SYS, including knock sensor)

[CSM, 1990, 6E3-A-22, 6E3-A-50, 6E3-B-1, 3]

If the ENG runs fine as a RESULT of a Code 42 reset, , I'd suspect:
OPEN or SHORT in CKT 423/424
Faulty IGN module or ECM

Link: http://www.digitalcorvettes.com/forums/showthread.php?t=39109&page=2&pp

Steven
 

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El Teafive
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It's junk now, I'll be by in the moring to pick it up.:laughing:
So you are giving him yours??? that would be okay, then your dad would have the FASTER car..

Bob, it is possibly the ESC Module could be having fits, clean the connections on it first and see if that fixes it..
 

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Discussion Starter #6
So you are giving him yours??? that would be okay, then your dad would have the FASTER car..

Bob, it is possibly the ESC Module could be having fits, clean the connections on it first and see if that fixes it..
Ok, I'll try that thanks. btw, I think Dad already has the faster car.:laughing:
 
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