[Shell22]

Greetings all, looking for advice on this issue, I've done as much research as I can get my head around (although admittedly without delving into physical wires and fuses) and think/hope its fairly conclusive it's the starter motor itself, however I've probably missed something hence this thread. I'll try not to waffle but it'll probably end up a little long...

Car is a 2007 335i RHD which is N54. Last 7 VIN: P054531

For context just in case I spent a few hours today swapping out coil packs to try and narrow down a misfire issue, went for a drive, came back and refitted original coils and then started replacing vacuum lines across valve cover and in and out of vacuum cans and solenoids. Car has always started promptly (after the ground strap replacement 12 months ago anyway, before it was a little slower) and also started after coil swap out as I was testing vacuum in the canisters. After all that, went to start the car again, had a fraction of a turnover i think then nothing. Attempts to turn over the engine now just result in a slight ticking noise then nothing. No codes via MHD. No battery low warnings (battery was replaced two months ago and registered) but threw on the charger just in case as I had left the door open and possibly key in the car for an hour or two. Will not start after charging or on the charger, just light ticking in the engine bay i think.

Now the diagnosis steps, first grabbed a jump lead and went from earth hex bolt to the engine, no change. The earth strap under the charge pipe is fairly new so I doubted that would be the issue but it was easy. I did try and check the larger positive cables within the engine bay as I read they can become brittle but no evidence of that either. After some more research I broke out INPA and checked for error codes, found a few as per below along with my findings on cause.

JBBF A6CF - Air conditioning sensor, should be unrelated.
EGS 511B - Alpina flash can cause this code, apparently fine to ignore. Car has XHP stage2 so I assume its due to that change.
CAS A0B4 - The expected code when a start fails from what I can tell, doesn't help troubleshooting.
FZD A670 - Misting sensor error for AC, again, ignore.
FRM 9CD4 - Something to do with headlights, unaware of any issues with mine but assuming not related again.

I tried clearing the CAS code but it returns, I also pulled the negative battery terminal for 30 minute, no miracle intervened.

Digging further into previous posts, I repeated some of the diagnostics, looking at the clamp control, it see's the gearbox in Park, it sees the brake when depressed, key valid. Looking at CAS Ignition I have good voltage with just ignition on, when i try to start the car i do get volts and amps across KL50L[V] and [A] and KL50RS[V] which I think means the starter is getting all it needs to fire, this is where I'm not sure what to do next.

Does this mean the CAS unit is triggering the starter solenoid and reporting it's doing so but there still could be a physical wiring issue that might prevent it? Or is this fairly conclusive that the motor is stuck and a replacement is needed? I did try knocking on it while someone pressed the start button but it didn't magically spring into life and didn't sound any different.

Any suggestions of further steps appreciated, not the most proficient with fuses and wiring but I have a multimeter, I've seen some diagrams from previous posts just not sure which are relevant in this case and what to attempt.

[gbalthrop]

Originally Posted by Shell22

... 2007 335i RHD N54. Last 7 VIN: P054531... Attempts to turn over the engine now just result in a slight ticking noise then nothing...

ISTA ScreenPrints are attached to NEXT Post, to maintain margins here.

Your INPA CAS Terminal Status Screen, BEFORE Start Attempt shows:
1) 12.21V at CAS Electronics Fuse, & 12.34V at CAS Load Fuse;
2) Activation of KL30G relay, KL15, & KLR;
3) That 2nd INPA Screen shows everything as it SHOULD be with Ignition ON, BEFORE cranking.

Your FIRST INPA Screen shows KL50L at 11.83V, & Current KL50L at 11.00A, presumably when START button pressed. Those values are in the range they SHOULD be, as far as the Start Signal from CAS to Starter Solenoid.

If the Starter Motor were actually drawing Current to "Crank"/Turn the engine, the Voltage drop would be 2 Volts or more (~ 10.0V readings instead of nearly 12.0V). Since there is LESS than 0.5V Voltage drop, it appears that the Starter Solenoid is NOT activating the Starter.

It is Possible that there is an issue with the KL50 Activation of the Starter Solenoid due to a wiring fault at either Connector X6011 or X60551 in the E-box. Apparently the ISTA SSP showing "X60531" is a misprint, where "X60551" is correct. Since you have to remove the Microfilter Upper & Lower Housings to remove the starter (& to open the E-box), I would test those two Connectors as follows:

1) Inspect the wiring (Black wire to White wire -- unknown if White begins at X6011 or X60551) at each connector: X6011/1 & X60551/2;

2) Identify the White wire that runs from X60551/2 to Starter Solenoid.

3) ENSURING that Transmission is in PARK & Handbrake SET (you are DEFEATING the "P/N Saftey Switch"), apply 12V+ from the B+ Jumpstart Terminal to the White wire going to Starter Solenoid. Just Tap it to see if Starter turns engine at all.

My interpretation of your CAS Terminal Status Screens is that the Starter Solenoid is NOT engaging the Starter. Where "Click" comes from when START button is pressed, & results of "Hot-wiring" Starter Solenoid would eliminate any doubt.
George

[gbalthrop]

Attached are ISTA ScreenPrints of 11/2007 build 335i N54 ECE RHd, as discussed in prior post.
George

[Shell22]

Thanks George for the summary of this so far, I've had a look at both connectors in the e-box and they look 'fine'. Nothing obvious or loose around them. I took out the plug for X60551 and pin 4 is the thick white cable that runs off in the starter direction. I placed a prong from my multimeter in that socket and placed the other prong on the 12v jump post across the engine bay. The multimeter read ~12v but the starter didn't make a sound. I hope I haven't failed to grasp something basic here :/

I also managed to get a contact on the large red 12v input to the starter motor and tested it with a ground, that also has 12v to it as you'd expect to the starter has a live feed waiting to be used.

I think I saw somewhere a way to turn the starter over directly from the back of the starter motor, applying 12v to the smaller bolt/fused bit next to the signal wire input, i guess that would prove the starter is capable of turning over ruling out the signal wire? I can't find where I saw that from so won't be guessing until I can check. Or just getting the signal connector off and getting 12v to that directly, which I can't reach easily currently without more disassembly.

[Shell22]

More reading and 12v to the fused bit I think would spin the motor without solenoid engagement, so pointless as the solenoid needs to be involved.

[Shell22]

Oh solenoid is separate from the motor, worth checking then, back to Google I go.

[Shell22]

As a final update, I haven't disassembled it all yet but managed to get under the intake manifold and remove the solenoid control wire from the solenoid, then bridged the 12v power to the control spade, no tick, no engagement of the solenoid so no turn over. My solenoid is dead. Great to prove that other parts of this process are functioning as intended thanks to many great write ups for troubleshooting on this forum, I've learnt a bit more about how it works.