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!
2005 hyundai accent will not start. Put new coil in and crank sensor. Has injection pulse but no spark.all fuses are good and powers and grounds
Coil is getting power but no signal from pcm. Pcm is not switching signal wire to 0 volts at pcm side, it stays at 12 volts when cranked or koeo.When i put test light on battery positive and touching coil negative or coil positive, there are relay clicks and an energising sound heard.Is this mean a bad pcm? There are proper 5 volt reference signals getting to tps and map sensors.
I never did anything with map code. The light did not come on to worn me. I checked it incase. I deleted code and never showed up again. Map does meen voltage circuit high. Would a map sensor cause a no spark? Also is crank sensor signal to pcm for spark or injector pulse?
I have checked for flashing with test light on battery ground going to signal wires of coil backprobed with t pin and no flashing just a solid light. I also did a comparison
On coil positive to see difference in starter current draw and was the same solid light as on coil negative. So no control. I also then moved the test light to pcm side coil negative backprobed with t pin and with koec got the same light no flickering.
My immediate reaction was a burnt out coil driver transistor in the ecu or wiring fault between coil and ECU But ISTR all the Hyundais of this era I have seen in the UK have one coil and coil driver for each pair of companion cylinders. So a coil driver failure would (normally) only take down a pair of cylinders.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)
Thank you for info and help. I suspect the pcm driver myself. The car could have burned out driver, as when car was jumpstarted wrong by my mother in law, the leads were connected wrong and it did take out the 120 amp alt fuse and burned coils out as they were bit melted. I did check continuity from ecu to coil wire signal and was good.
Thank you for continued help with this. The battery was drained way down as originally there was a drain on battery as i found a branch that was sitting in trunk area causing the trunk light to stay on as it was not closing properly. Car ran perfect before jumpstarted wrong.
As in your previous reply you mentioned possibility another input to pcm may be missing, perhaps camshaft sensor? It could be the crank sensor controls fuel injectors and camshaft sensor is input to pcm yo fire coils, not sure. I found a diagram showing the pcm is ground side switched by ecm opening a relay to to send Ground to injectors, but did not see the coils in this circuit. But if camshaft sensor was bad pcm should throw a code? Getting back to your map sensor reply, there is no shorted to ground and there are 4 terminals on this and pin 1 is sensor signal and it is 5.5 volts. Pin 2 is 5 volt reference and it does have 5 voltss. Pin 3 is sensor ground and it is 0 volts Pin 4 is air temperature sensor. Didnt record this one.
I did unhook ground for 10 min or so as you suggested to rule out driver, if it was in shut down mode for protection, and still no go. I then decided to open up pcm as there was 4 torqs screws on each corner. I looked for obvious defects and seen 2 chips that are 1/4 inch wide that are burned up a bit and have that distinct smell. It looks like you andy were right and These two chips must be the drivers, one for each paired coils as Andy mentioned. Thank you for your help and quick reply to my messages, greatly appreciated.
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