FIXED Crank no start, no spark

Wow it does look like the transistor is in the PCM judging by the second waveform. Interesting. Why the 3 wires on the coils then... constant power, constant ground, and a computer controlled wire. I would like to know what the voltage is on the middle pin of the coil.

Thanks for the waveforms. Flyback voltage spikes make it looks like the driver is in the PCM and it controlls ground side. So the primary must be 1 and 3. When computer commands 1 to be ground it energises the primery coil. When it switches off we see spark and flyback voltage spikes. seems legit ^)

jonathandean wrote: Thanks again for your help. No I can't make the coil fire, maybe I am doing something wrong but no the test light doesn't illuminate when I touch it to the comtrol. There is some very low voltage on the control wire,it was below half a volt and not constant, i measured it with a scope but the voltage level seemed negligible to me, a very small amount. I hope this info helps thanks Jonathan

Regarding your measurment of half a volt - a very good case study by Ivan
Can not insert correct timing - the forum doesn't get it right. The moment about measuring half a volt starts on minute 19.

Right, had one of these in for mot today so grabbed this for you
Back probed the coil in cylinder 1 (timing chain end, what the French call cylinder 4)

Great info. Wish the yellow channel was a bit close to the green scale.

Here is the shopstream file if you want to put the cursors in for the voltage measurements

The car is fixed now, there is a TSB for the body control module on these cars, also called the BSI module, it appears when the garage did the headgasket, when the re connected the battery the control module got confused and effect wouldn't turn the immobiliser off.I cant explain why i couldn't make the coil fire, and why there was no codes stored.
Thanks for all your help,and to everyone who replied, this forum is a really fantastic source of help and information.

Jonathan

Hi, Just a question if you don't mind, what tells you the transistor is inside the ECU? Thanks Jonathan

You can tell by what you see on the control wire
If you see coil negative



Then the transistor is in the ecu

If you see a square wave then the transistor is in the coil



Here's a good video

please tell me what you did because my car is doing the same thing now