chitty

I'm trying to help my father diagnose his car - no crank no start condition after coming back from vacation.
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The issue:
- Accessories turn on, when trying to start, no crank, and all accessories shut down instantly
- Father said he experienced this in the past and was able to start the car after successive attempts. (past month)
- Said he experienced lurching-like symptoms while driving after starting, and then lurches went away after pulling over, and idling a bit

Existing Conditions / actions
- replaced battery terminal - was loose on negative - no start
- trickled charged the battery - no start
- jump the car with known good battery - no start
- steering wheel isn't locked
- Battery is 2 years old
- Key unlocks the car and locks / opens trunk etc. replaced key battery - no start

Suspect:
- At this point it seems like the starter but does not explain the the lurching my father described which sounds more like a fuel cut / ignition cut situation - what do you think?
- Don't believe it is immobilizer - heard this locks the steering wheel too
- Don't believe it is alternator - as a jump should still cause the starter to turn

Dash lights when accessories come on include:
- Battery
- Oil
- Master (Triangle / Exclamation)
- SLIP
- AWD
- VDC Off
- Brake
- red car with key silhouette on speedo
- yellow "KEY" with key diagram on tach

so basically a lot, but the car was in working order / maintained before this issue appeared / no dash lights before

Thanks Team

chitty

Edit - I'm going to replace the starter this weekend. I'm wondering if the lurching is from the starter solenoid failing and / or failing to disengage the starter pinion.

ILM-NC G37S

iTrader: (3)

First, do not assume that one is a symptom of the other. Your father would have heard a loud grinding/ screeching sound if the starter bendix drive was not releasing once the car started.

There is no sense in doing all of that extra work until you test the starter first. You can run a jumper wire directly from the battery to the "S" terminal (white wire) at the starter solenoid and see if the engine turns over. Alternatively, you could jump the white wire at the IPDM/er (pin #80) as shown in this post.

What year is this car? And, to state the obvious, any water leaks?

chitty

Thanks, I'm making assumptions based on what I know and posting here hoping for people to put holes in them - so I'm glad you're here to give guidance on diagnostics.

I'll try to jump the starter directly at the solenoid to gauge starter / solenoid function.

As for water leaks - also yes - i believe the sunroof drain is partially clogged and water runs down the A pillar and collects at the driver side footwell during larger storms. However, father reports no water in car when trying to start the car after returning from Vacation.

The vehicle is a 2009 G37x coupe

ILM-NC G37S

iTrader: (3)

I am 99% confident the starter is fine. Being that all of the electronics "black out" when trying to start the engine, usually indicates that the "system" is not sending the engine start "signal."

The issue appears to be electrical and my bet would be that the fuse block got wet and the fuses/ relays might be compromised. I would also suggest you actually pull up the carpet on the passenger-side and make sure it is dry.

Between the BCM and the fuse block, any water on these units can potentially brick the car.

chitty

Will check - if one side is partially clogged the other certainly may be. One of the reasons I felt it could be solenoid related is the arc described HERE - do you think this would trigger a short-out / blackout as well?

ILM-NC G37S

iTrader: (3)

It could very well be the "S" terminal. Easiest way to test is to jump the white wire. That will tell you almost immediately. In most cases when the solenoid fails it just clicks or just does not engage, but the car accessories remain active. You had said that during POST everything comes on but goes black when you try to start the engine. Do they come back ON or do you have to cycle the key first?

Either way, try jumping the white wire at the IPDM/er (mentioned/ linked above) and see if the engine turns over. If you get the click, or a arc, then you can clean the "S" terminal contact at the solenoid and try testing again.

Removing the starter is a last resort as it is a real PITA to get access to- especially on the AWD "X" cars... If all of the above fails, then you will have no choice but to remove the starter and have it independently tested/ rebuilt/ replaced.

And, friendly reminder, before touching anything at the starter itself, DISCONNECT THE BATTERY! Though you might have "S" terminal issues, there is still 12V constant at the "B" terminal.

chitty

Big thanks again,

Here's a video of the POST and button press: I need to press the button again for accessories to come back. No solenoid click whatsoever with ear at driver footwell.

Jumping the white wire in the fuse panel creates a weak turnover for about half a second at very low rpm then stops for good. (Grind-halt) And jumping the wire with positive only to the wire and not the rest of the car creates a solenoid click. The battery has been on the trickle charger for a few days and sits at 12.6v

Jumping from a running car all else the same as above the starter turns over very slowly about one grind per 3 to 4 seconds.

Dunno why jumping turns the starter very slowly but the start button does nothing. Seems like both a signal issue and a weak starter?

The passenger floorwell feels dry after peeling back the floor mat.

ILM-NC G37S

iTrader: (3)

POST appears normal. So that is a positive note. Also, dry cabin is a plus in your favor.

I would suspect a weak battery. Just because it is reading 12.6V (surface charge) does not mean it has the capacity (amperage) to turn the engine over. Even though is only 2-years-old, many factors can affect battery performance. Plus, we do not know how deeply discharged the battery may have become while your family was away on vacation.

If you have a known, good battery that you can swap in temporarily I would go that route. Then, if jumping the starter connection still produces a weak crank you will have to check the starter/ solenoid. Traditional jump starting may not be effective given the unknown state of the battery and the gauge of the jumper cables.

re: start button "does nothing." With the start button a whole series of signals are transmitted and relays which are closed- all which require additional power. Power that the battery appears is not able to provide whereas when manually jumping the starter you are applying 12V directly to the starter.

chitty

Thanks - I took the battery to get tested by the local auto big box to load test and they confirmed it was fine. The jumper cables are pretty beefy and I don't believe there's a current loss or contact issue with those (reliably start other vehicles with these cables / source vehicle over the years). I will do as you suggest and put a known good battery directly onto the terminals nevertheless as a final test.

Is there any way to test the relay that's integrated into the battery-side fuse box? I was wondering if I was triggering the relay or directly supplying power to the solenoid but you've confirmed that it's direct power.

My replacement starter arrives today I think I need to go deep at this point whether to test the solenoid/starter while out or do a full replace. I just replaced a 911 water pump so relative to that this should be less of a PITA... I will attempt the forward and out past the swaybar method vs the steering u-joint method.

My understanding is that most replacements are pretty terrible (including the one arriving today) - I've never had anyone re-wind / rebuild a starter before. Do you have any mail-to shops that you might recommend?

ILM-NC G37S

iTrader: (3)

While I am not a fan of "box store battery testers" as opposed to true carbon pile testing, I understand the constraints and whatnot. As a last ditch test, try using a known good battery and see what happens.

If you are applying 12V+ directly to that white wire (linked/ posted above) that is the same as running a jumper directly from the battery to the starter solenoid.

Alternatively, you could test the starter motor itself. If your jumper cables are long enough, you could put the cable on the starter post itself:

This would effectively test the motor post solenoid. If the starter engages, bad solenoid. If not, then either a bad winding, contact brush, or other internal fault in the starter motor itself.

Where did you get the replacement starter? There are literally tons of used starters on eBay for next to pennies. I am not aware of any "mail in" services to get starters rebuilt. The few times I've had them rebuilt I had a trusted shop do the work. In all actuality, it would be cheaper to just replace than rebuild these days.

I wish I had a magic answer for you- but as with anything electric, it takes a lot of testing and some trial-and-error before you hit the nail on the head.

chitty

Thanks again, certainly not looking for the "right answer" and simply just enjoying the dialogue here - and reading between the text to absorb your thought process on diagnostics. You've been very helpful pushing me in the right direction.

I ordered a very inexpensive no-brand starter:
While there's a lot of life left in this vehicle, it's my intention to have my father sell it to replace with a newer vehicle, thus the inexpensive starter.

I'll run diagnostics on both the solenoid and the starter and may take apart the starter for my personal edification to check brush condition, contact area wear, and general winding condition but the cost of a solenoid is so similar to the cost of a starter that I will just replace the entre thing altogether.

ILM-NC G37S

iTrader: (3)

Despite all the modern "bells and whistles" and other electronic "gizmos and gadgets" certain aspects of the automobile have not changed in almost a century. The starter and charging systems are examples. The starter is a simple, dumb 12VDC motor. Apply 12V and the motor spins. If it doesn't then either it does not have enough power or there is a physical fault. I will admit that these Hitachi units are pretty bulletproof but even then, anything can fail.

As your end goal is to pass the car on, I am sure the cheap Amazon unit will suffice.

Could be worse. In the old days most engines were cranked by hand. Talk about a pain in the ą$$... and your wrist.

I can't count over the decades how many parts I disassembled to figure out issues/ what went wrong/ etc. For some, that is the most effective way to understand how things work.

chitty

Well, it took a while to get the dang starter out.

• Out of the car on straight battery power, the old starter seemed weak when hooked to 12v, but the new one twisted with torque and seemed more powerful.
• Same exact no-start condition after install, and same results when jumping the white pin in the IPDM etc.

Next will pull the BCM and inspect for signs of water / oxidation - that side of the car feels very dry to the touch but maybe water went into the BCM without soaking the carpet.

ILM-NC G37S

iTrader: (3)

I do not understand why when applying 12V+ directly to the white wire the starter does not engage.

Based on that finding, I would suggest running a few more tests:

• run a continuity test between the white wire at the IPDM/er to the starter. Disconnect from the IPDM/er and test from end to end. Should read zero (0) ohms;
• it wouldn't hurt to check continuity on the main wire going from the battery directly to the starter motor itself;
• disconnect the white wire at the IPDM and, with a helper pushing the start button, read voltage at that pin on the IPDM/er. Should read 12V+;
• check that the negative cable where it attaches to the frame is clean and solid. Alternatively, you can run a jumper cable directly from the negative battery post to the engine; and
• check the battery voltage at standing and also during cranking- this will help determine voltage drop.

If the new starter is weak then the issue has to be power/ ground. Then again, you can not rule out a potential issue with the BCM/ IPDM/er either.