Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Hi there. I have a 2005 Chevy Malibu 2.2 Ecotec. I have a no start condition. I have power and ground to the ignition control module, but have no ignition control signal at either pin at the ignition control module. Replaced the module and no change. I also have no DTC's but do have reference signal from the crank position sensor.
Hey Supertech! Were you checking for the ignition control signals with a scope? I ask because they're pretty quick pulses, and can be easily missed, even with a scope. ScannerDanner ended up chasing those signals in a video on a 2.2L. :lol: Scope setup had a lot to do with it.
Before that, have you confirmed no spark out of the coil boots? Just suggesting if you haven't already, as the presence of spark would allow you to skip checking the control circuits.
Next would be fuel pressure during cranking. An '05 Malibu would be a prime candidate for a fuel pump. If you don't have a fuel pressure gauge, you can always try giving it a shot of alternate fuel in the brake booster hose.
Hi there! Thank you so much for your response! I have 55 psi fuel pressure. I have no spark at all. Doesn't fire on carb cleaner. I apologize, I should have written that in the post. I checked for the ground pulse of the ignition control signal from the ecm with a noid light according to the service manual. Not a fan of the wasted spark system, lol. And even the service manual isn't very clear. I was an ASE Master Tech for almost 20 yrs. I'm retired now and trying to help my neighbors daughter. I miss the shop where you could bounce thoughts off the other guys, lol. Thank you again
Ah OK, you've been down the spark and fuel path. :lol: :blush:
Is the ECM supposed to supply a ground pulse to the ICM? I always thought it was a 0-5V voltage pulse that activates the power transistors in the ICM to control primary current flow. ScannerDanner has a video out on this system, if you haven't seen it already. Scroll to around eight minutes for the scope capture:
Sure sounds like the SI is misleading. Not sure why they want you using a noid light... The ECM to ICM control signals are usually less than 20mA, so they'll never light anything. :lol:
Sorry for taking so long. Been crazy with the kids going back to school. The ecm sends ground pulse to the module. The video is how I found this forum, lol. I did figure it out. Even though she claimed no noise came from the engine when it died, I did a compression test. No compression on cyl #1, 2, or 3 and 50psi on #4. Pulled the valve cover and the timing chain tensioner came apart. So, basically since that wasted spark system uses synthesized cam signal using compression and coil voltage response, it couldn't read any cam movement, so no cam signal. Thank you again for your help. It was nice having another guy to brainstorm with. If I can ever be of help to you, just let me know. Donny.
Oops. :ohmy: Sorry to hear the timing jumped, sir.
You've definitely accounted for the lack of spark, though. Definitely misleading. I wonder what that synthesized cam signal looked like? :huh: As in, if the ICM was even attempting to create a signal, or if it was just flat lined.
I dunno how much I helped you brainstorm? :silly: Mostly talked about stuff you'd already done. But we're always here to bounce around ideas!
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