So, it is time to try to start the car...
Before I could even attempt to start it though I had to align the EWS and DME
(5 seconds later)
Cool. Time to crank!
And uh, well, the first crank was a total dud. Nothing at all. Not even a single click, crank or anything. Time to do some digging
As it looked in INPA like the EWS/DME alignment was successful, the first thing I wanted to check was the starter signal output line from the EWS. On the Z3 this feeds straight to the starter. On the X5 and the way I had re-wired my setup, was this signal feeds into the IVM, which then outputs it's own line to the starter. I believe the reason it does this is because of the X5 "comfort start" feature, which means you just turn the key over into the "start" position for a second and it will engage the starter on it's own until it starts the engine (so you don't have to hold the key in the start position while it cranks)
This signal line did have 12v when attempting to start - which, along with the lack of EWS manipulation codes in the DME, meant the DME and EWS were paired successfully. So that was a big win! But I still had the issue of the no cranking or anything. I figured at this point I had some issue in my starter wiring
I did want to test the starter though, so I bypassed the IVM and ran the starter signal straight to the starter. In doing so - I got a single "click"
Hmm
So still no cranking, but this confirmed at least some of my ignition wiring was wrong. I had altered some of the ignition wiring and the "Start signal" lines in the DME pinout seemed to match and I moved them into the correct terminal for the X5 DME. So those seemed good. It was time to do some research...
Lets look at some diagrams together
This is the Z3 starter circuit. Red is the power to the ignition source - and ultimately the power supply of the starter line. Orange is ignition to EWS and yellow the EWS output to starter (this is the line I have confirmed working)
Just to understand how simple that circuit really is at it's core, below is the X5 6 cylinder starter diagram, which is the same diagram as far as routing but without all the extraneous EWS stuff shown in the above Z3 diagram
So, so simple. This is pretty much how starter circuits have worked forever
Now lets check out the N62 X5 starter circuit!
Cool... super cool...
So what the hell is going on here?
We have two power supplies, as you can see at the top. A smaller power supply goes to the ignition (on the top left) and a larger supply feeds the IVM (60a) which is marked with the red line (the red line signifies the circuit that will ultimately send signal to the starter)
The orange line on the left is our ignition output - this is the thing that tells the whole system "Hey, I'm trying to start over here!!!" - you may observe that on the N62 X5, this feeds into the DME and not the EWS
The DME then has two lines (pink and blue) that feed into the IVM. The pink line is one I didn't have to think about - it runs on the engine harness. And I already ran the blue line earlier as part of my wiring changes so that part of it was good
The yellow line is the EWS output - I confirmed this output line was getting 12v when cranking, so I did not have to worry about my EWS wiring or anything upstream of this
Green feeds the starter, from the IVM
When I ran the EWS output (marked yellow in the above diagrams) directly to the starter I got a single click at starter. However, with the way I configured it originally, it did not click when ran through the starter...
In tracing the problem I realized the first step was to find the X33 junction - it's the black plug under the steering column, then I verified this was the correct wire I needed with a continuity tester
Now that I found the pin, the next step was to de-pin it from the harness. This is it loose and ready to pull out
This was the adapter I built. It's pretty simple - the black is a long wire that goes to the DME. Red wire will go into where the other terminal was de-pinned, and the white plug is where the original pin will now sit
The de-pinned pin on the harness
Pin installed in the harness
And the wiring harness plugged in (the red goes to where the pin originally plugged in, black goes to DME)
And all together!
The black wire was run to the DME and plugged into the correct spot as well. The end result would be a wiring diagram like below
Then I tested it and... click! Which is a good sign, it seems the circuit is working correctly now. But the question now is, why is the starter still not cranking? Hmm
Few things to investigate but testing the starter itself will be one of the first things I'll be doing
I also did spend some time investigating the steering rack fitment as well... not critical at the moment but, it looks way better now with the O2 sensor out
Installed in place (loosely) on the splines
Hard to tell but there is some clearance...
So the next day I realized I popped a fuse at some point. Actually 3. Dang. I traced down part of the problem to being a wire on the IVM body harness - it was wired to 12v (behind a 10amp fuse that popped). It is actually supposed to be a 12v output, to the e-box fan...
I re-wired that and installed a spare IVM just in case
Shortly after I finally figured out the reason the starter was just clicking... it was an issue with the main supply circuit for the starter. It isn't making a good enough connection - I ran a jumper cable from one end of the starter supply cable to the other, supplied the signal with 12v I tapped from elsewhere (because the correct EWS starter output won't work now since there isn't a DME) and...
Now I will wire it back up the correct way including running a new starter supply cable and try to start it. I have a couple other things I would like to finish in the meantime though, so I will work on those in the coming days.
Most notably of those things I want to fix is that the oil level sensor harness does not fit on my current setup and is currently not plugged in. The reason for this is that I am using an X5 engine harness and E60 oil pan but the X5 and E60 oil pans are different (because X5 is AWD) and they place the oil level sensor in different locations.
I decided to extend the oil level sensor harness
So first I mocked up how much length I needed... just used tape, for convenience
The oil level sensor plug off the old/spare engine harness
Peeled it out of the harness a bit...
After it was cut at the correct length, I cut the sheath on the existing harness and cut the wires, with my cuts being staggered
I did the same, with the lengths inverted on the plug-side and started to put it together
With the wires connected, it was time to try to get the sheath back in place as best as possible
It's a little hard to tell but on the plug-side, I used a little harness tape to tape the sheath in place
I then pulled the sheath down from the engine harness side, to cover the joints and seal it up
I wrapped this in harness tape and then had heat shrink which I had slipped on earlier over all of it to secure it as best as possible from the elements - especially critical given where this will be sitting (just hanging underneath the car)
Below is it all installed in place
The DME's arrived so the first course of action was to finally install that 5amp fuse for the ignition line to DME
I also had to get a new multimeter, as my other one had one of the probes break. It was a very welcome upgrade and now also has a visual indicator (green light on the top) to visually indicate continuity
During the next start test it did crank! However it still didn't start. I attempted to communicate with the DME via INPA and kept having issues. Ends up my cable had communicated to it's last DME the day prior... I did have a spare at home though
Once I did get connected, I realized I totally forgot to align the DME and EWS and it had an EWS code as a result
I then aligned the DME and EWS again...
At this point the EWS code did not come back however it still did not start. The only codes present were those below, plus a "DSC message timeout" which isn't pictured because my phone died
Further digging revealed that the crankshaft position sensor was not sending any signal during the start attempts - this was likely the source of the issue. First thing to check was continuity between the sensor and it's pins - it gets a voltage supply from the IVM and two wires to the DME. All of the wires checked out good
Next was to check for voltage at the sensor when running. It did have voltage. I checked my own personal N62 X5 sensor just to be sure and it had voltage on the same pins
I was originally thinking it was some sort of EWS related issue because there was an "EWS OK" status that never lit up on INPA. However, on my N62 X5 this did not indicate "on" at any point before, during or after starting so I am no longer suspecting the EWS... although, my research did reveal the starting diagram for the N62 is much more complicated than I originally thought
The teal lines (on the left) are wires I was not previously accounting for. Purple is a transmission line I do not need to worry about as the EWS is coded for manual. More research did reveal that a lot of the "unknown" were already addressed at some point in one way or another, but regardless, I found the complexity of this starter diagram intriguing
I definitely understand a bit more about why a lot of people - particularly mechanics who focus on non-German cars - complain about the complexity of the electronics in these cars. This reputation, apparently rightly earned, was amplified tremendously with the release of the E65 which of course was predominantly N62 powered
I think this start attempt will need to spill into a new post as well... it is getting to be a bit too long of an update. So, onto Part 9
Comments