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Help me with 2006 Buick LaCrosse 3800 engine.


Homeby51
04-10-2021, 10:25 AM
Cranks but won't start. I checked the computer and it gives me a misfire cylinder #4. I cleared the code. Checked for spark and not getting any spark on any wires.
I have 12V coming in to my Ignition Control Module (I think purple wire) so my input voltage is good. Then I checked the ground wire and ground is good (Measured ground wire on ICM plug to positive battery terminal). I also checked with my meter the frequency coming from my crank position sensor and the meter registered a change in frequency when cranking. I assumed that means I am getting a good signal from CPS?
I then removed my coils and I checked for 12 volts at the pins on the ignition control module that supply 12v to coils. Nothing on any of the three, Sooo...I changed the ICM. But still nothing out of the coils.
I checked the computer and am not getting any faults.
I guess I should swap the CPS? Nothing else to swap...right?

HotZ28
04-10-2021, 05:40 PM
Follow the procedure step by step and let us know what you find out. Good luck!

http://easyautodiagnostics.com/gm_ignition_3800/test_ignition_module_1.php

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