not cheap though....have to save my euro's for that....

 

Ok, removed wheel, removed panel, was shocked at the condition of the ECU and 3 connectors, they were really bad, covered in sand/grit, connectors really difficult to remove with the crude, nearly a whole can of contact cleaner on getting them off and cleaning the pins and plugs.
Ok now down to the serious stuff, i want to start testing with the scope at the ECU end as you have suggested Rob, but iv never back probed an ECU and can't see how i can get to the wires as they are pretty much completely covered by the plastic casing.
I know you do it by wire piercing probe but i dont have one at the moment but do have the normal back probe pins, any idea's how i can get to where i can back probe?
Also would i need to put the connector back on the CRK sensor for testing? and same for the injector tests, does the CRK need to be plugged in?
i'm guessing it does as the ECU needs to see Cam and Crank signals to fire spark and deliver fuel, not sure on that though.
And because getting parts for me takes about 2 weeks from the States, iv just gone ahead and ordered Cam and Crank sensors to cover all bases, even if one doesnt need to be changed at least i have it ready for when its needed.

 

 

Ok, will do, i will plug CRK sensor connector back in, and check injectors and watch video's for todays tasks.
Great info.
Many thanks, have a great day. i'll get back to you later on results.

 

No problem !!...yes, check injector pulse first...here is a pic of the plastic covers and the release clips on the end

...pinch together or small screwdriver to pop them off...let me know about the back probing and I'll get to my PCM !!

 

Ok today's tests....
Connected crank sensor back in, connected ECU connectors back, (BTW my connectors at the ECU are totally different to yours, i've attached a photo to show you, very difficult to get to pins)
So i've ordered a piercing probe from Amazon, it will be here tomorrow afternoon.
So today, used test light and checked all injectors and they all have ignition 1 voltage, and they light at KOEO and they all pulse (although quite slowly, i expected quite a fast pulse)
So all looks good on injector side of things i think? (I made a video of the pulse so you can tell me if it's normal for cranking) i have put a link to dropbox with the video
https://www.dropbox.com/s/96vn1bla2n...pulse.mp4?dl=0



Fully enclosed, very difficult to get to pins

 

Great job !!...your injection pulse is fine cranking...it will pulse faster when it's running...oh boy !!...with good injection feed and pulse that puts us in a different "funnel" now...I thought for sure with no tach movement we were looking at crank sensor...maybe it doesn't work on the C6's....don't know for sure...maybe someone can chime in...now we just have to look at ignition but I think you should still check that fuel pressure too. Now on the C5 the injectors AND ignition coils are powered through the same fuse...are yours ??...mine is fuse 18 and 22...since you had injection pulse on both banks I'm assuming we can assume the feed is also good to the ignition coils...now does your ignition coil harness look like mine...one at each fuel rail ??...pic enclosed...I disconnected the harness and checked GROUND (G107)...test light connected to battery positive and touched tip to the black/white ground wire...light came on so ground is good (pic enclosed)….if your harness is the same let's see if we have a good ground. My G107 sits behind the LEFT (drivers) cylinder head...check your ground wire there...might be able to see with an inspection mirror. On the C5 there is a bracket on the rear of the left cylinder head...there are issues with wire chaffing there...injectors and coils run through that harness...check there...I put another coil of chafe tubing there on mine...how did you check that you had no spark ????

 

Yes your right i think we are looking at ignition side of things rather than fuel.
Yes the injectors and coils run from the same respective fuses, i.e fuse ODD INJ does one bank of injectors and coils and fuse EVEN INJ does the other bank.
Both fuses are tested good.
I also checked for 12v on the main 8 way coil harness which feeds all coils similar to your second photo...that also checks out and the grounds as well.
so tomorrow i need to check the ground at the back of motor.
I checked no spark with a spark tester similar to a test light, but designed just for testing spark.

 

So, do have a black/white wire from the harness that's connected to ground and it's GOOD ??...that black/white turns into a black wire at the other side of the harness and that is the ground for each coil. If that ground is good now we have to look at "control"...no control from the PCM...we are just assuming we are getting a good crank signal but we do have injection pulse though...MMMM ???

 

I just need to find pin 62 dark blue/white at the ECU with a piercing probe and test with the scope for crank signal. as you can see from the pics above its going to be difficult to find the right wire to tap into.

 

i will double check that ground wire for all coils tomorrow, iv checked it with the probe and it gives me a ground signal but i want to back it up with a DVOM for GOOD ground.
I'll also check that its the black to black/white as well.
Also we dont know that we are getting a GOOD crank signal as yet, i havent got to test that side until i find that wire at ECU to scope

 

Usually the ECU/PCM pin outs are numbered...mine is C1 and C2 and numbered from like 1-72 or something...the end numbers might be on the side of the PCM !!

 

I know which connector the CRK wire is in and also the pin number and the numbers are on the ECU but the problem is that the connector would have to come off to count the pins to find pin 62, but then the problem is that because of the big plastic casing its in, you cant actually see the wire exiting on the other side to know which one it is, the only time the wires become visible is when the exit the rear of the connector about 2 inches away from pin and when they exit they are just bundled tightly together with a cable tie.
So what i will have to do is cut the sealing tape back so i can open up the bundle a bit more and then hopefully just find ONE dark blue/White wire, then i know thats the one. if there are more than one dark blue/white wires then i'm gonna struggle.

 

I checked out my pin outs and on my C1 side I have 2 dark blue/white wires !!...crank signal and #8 injector control. don't know if yours are the same but if I didn't know which one mine was I'd disconnect the #8 injector...then ohm out each wire using the piercing probe at the PCM...you have a 50-50 guess...the one with continuity is the injector wire...simple enough !!….I just looked and yes my #8 control is dark blue/white !!

 

Yep, just checked the wiring diag for my car and its exactly the same as yours dark blue/white is both crank and #8 injector control.

What OHM setting would you use and what reading should i expect OL?

 

If I use my DVOM I usually leave it on 20K...no, OL (open loop) is a resistance (infinite) that is more than the DVOM is capable of measuring. At 20K mine will go from "1" to "0" if there is continuity !!...If using my Vantage Pro it is auto ranging and I don't have to change anything !!

 

my DVOM is auto ranging so it should be a piece of cake.

 

 

volts or ohms?