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MongoMF
08-17-2018, 06:37 PM
New member - assistance required with 1227747 which is installed in a 81 Jeep CJ5 with SBC350

I've been tracking down a "no starter" condition that was occurring only after driving for a period. After many steps of problem determination, it was found that the problem is not the start/solenoid but the starter wire from the ignition switch. Tracing this wire back from the solenoid I've located a splice that branches off and connects to Pin "C9" of the ECM. The documentation available indicates this is the "crank signal"; however, I'm questioning the original work done during engine swap and perhaps a misinterpretation of the term "crank signal".

Is connecting pin C9 to the starter/solenoid correct or is pin C9 for the crank position sensor as the information uncovered suggests? Or perhaps the connection is needed for some undetermined reason on this "Franken-Jeep".

Appreciate any assistance/guidance.

MongoMF
08-17-2018, 06:51 PM
Not long after posting my question re: pin C9 the following was found in a larger wiring diagram.
13254
From this diagram the wiring to C9 is correct. I suspect now the issue is the ECM failing.
In light of this new information, does anyone have a pointer to what this "crank signal" does for the ECM

Eds
08-17-2018, 08:39 PM
You do not say if things to cool down the engine will re-start or not. If so, before declaring a failing ECM, I would look at the ignition control module. I have experienced a situation where the heat transfer compound under the ICM dried out and wasn't transferring heat. Cleaning things up and new compound fixed the issue.

dave w
08-17-2018, 08:40 PM
I suspect the function for the "Crank" signal is for the ECM to enter a different injector firing routine when the engine is cranking. Newer computers have several parameters for "Start" programming.

dave w