1979-1993 & 94 Conv [Subscribe to Daily Digest] |
[Main C900 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Be there external faults which wound but not kill ? Posted by mag [Email] (#1906) [Profile/Gallery] (more from mag) on Tue, 29 Apr 2003 00:27:37 In Reply to: What external faults can fry an ECU?, mag [Profile/Gallery] , Sun, 27 Apr 2003 17:53:18 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Thanks for the input so far. It means loaning ECU's can be dangerous to the ECU unless skill is carefully applied.
I want to probe a bit more. Are the external faults we're talking about (overvoltage to the wrong pins) always fatal, that is, lead invariably to vehicle no-start no-run conditions? Or can they cause damage which leads to poor drivability?
The answer informs the diagnostic rules. Consider:
Rule 1. If the vehicle is a non starter and the ecu is suspected, one MUST pin check at the ecu connector before risking a new ecu. Also check for the correct AMM.
Rule 2a. If the vehicle starts but runs porly, and the ecu is suspected, the ecu may be swapped as a diagnostic wihout risking the new ecu.
Rule 2b. If the vehicle starts but runs porly, and the ecu is suspected, a new ecu may NOT be swapped in as a diagnostic because there are possible external faults which can damage an ecu and so produce these poor running symptoms.
Either Rule 2a or 2b is wrong, and I don't know which.
Obviously it would be advantageous to DIYers if Rule 2a was the true one. Alas, wanting it does not make it so.
mag
posted by 66.81.81...
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.