2010 Chrysler 300c CRD 3.0 V6 diesel no crank, no start, not the usual suspects?

Hey all. I’m from The Netherlands, working as a technician for a taxi company with a small fleet of about 50 cars and vans. We have a 2010 Chrysler 300c CRD with the 3.0 V6 diesel engine. I’m having a problem with it but since this car is very different from our European cars electrically wise I need some guidance here.

Car was dropped off for an inspection at the APK station (APK is a mandatory, periodic technical inspection of a motor vehicle's roadworthiness similar to an MOT in the UK). The mechanic there drove the car up on a lift and while idling it died all of a sudden. He tried to start it back up again but nothing, it doesn’t even crank anymore. He called us and we had to tow the car back to our own shop. Unfortunately I don’t have a scope, I did check the car on fault codes but that proved to be useless, I have a Bosch KTS but it shows mostly “unknown fault code found” messages which doesn’t really help. So I basically have to work with a multimeter and a led testlight....

I did make a couple of basic checks and found the following:
With ignition on, all lights in cluster function, everything functions like it should. Checked alarm system, works fine, upon unlock red dot light in cluster stops blinking so alarm arms and disarms. First thought was maybe immobiliser but not sure....

Looking further at TIPM under the hood I can bypass the starter relay and by doing so the starter spins the engine around without any problem. The engine does not run this way, but atleast I can rule out the starter solenoid, the exciter wire to it, the starter motor itself and the battery which was replaced a few weeks earlier. This car has a push button start with a removeable button but both button and key fob turning does nothing. Both fuses next to the starter relay are ok. I noticed that when starting the starter is energized for a split second and then nothing. After waiting for about 10 seconds, start again and same thing, a short “click” from the starter engaging and that’s it. I confirmed this by using a led test light across ground and one of the coil pins of the relay. In start mode that pin gets voltage for a split second but no longer which is the “click” you hear from the starter motor. Now I’ve read somewhere one pin to the coil gets 12v from the fused ignition switch output and the other gets ground from the ECM but I can’t find that anymore so I’m not certain if it’s pin 85 or 86 I’ve been checking which is a bit dumb on my part. Feel free to correct me on this.

Anyway, it looks to me the control circuit side of the starter relay, more precise the 12v feed to the relay coil is at fault here.

I’m going to pick this up Monday if I have time but I guess the question is, what do I check next? Could it be the wireless ignition module? I believe it can cause a no crank no start as well but since the working principle is very different from a normal switch how can I check it? Or should I suspect the TIPM? What causes the starter relay feed to come on for a split second and then switch off?

Anyone who has experience with this, or knows what to look out for?

Thanks in advance!

Eric.

PS, something went wrong, sorry for double posting this.

63FB wrote:

I’m going to pick this up Monday if I have time but I guess the question is, what do I check next? Could it be the wireless ignition module? I believe it can cause a no crank no start as well but since the working principle is very different from a normal switch how can I check it? Or should I suspect the TIPM? What causes the starter relay feed to come on for a split second and than die?

I wouldn't get too deep into the starter control with no scan tool, and probably no S.I. either. The stall and the no crank likely share a common cause. Unless the "other shop" screwed around and broke something else......

First thing I'd try is another scan tool. Preferably something with global coverage like the X-431 based tools. Or if you have an ELM327 bluetooth dongle then AlfaOBD would be worth a try. Even a code reader to see if the ECM will communicate and update generic PIDs. Or if you don't have anything else you can plug into this thing see if the Bosch has a generic OBD-II/EOBD mode you can try. If you can't find anything that'll talk to the ECM check a couple 3 wire sensors on the engine to see if the 5V reference is up.

After that I'd likely go after power distribution. Hopefully the fuse boxes are labelled. If not try the owners manual. Might find that online if the treeware copy is MIA. One thing to watch on FCA vehicles is some of the engine power is switched by an ASD relay. It's controlled by the ECM in a similar way to a fuel pump relay. Only energized for a couple seconds when the key is first turned to run then doesn't come back on until the ECM senses engine movement.

Hi Matt, thanks for your reply.

I agree, both problems likely share a common cause, but at this point I can’t figure out how both problems are related and could occur one after the other. That’s what’s keeping me awake at night...

Good info to look for the 5v reference, I’ll try that if all else fails. The Bosch does have a generic OBD-II/EOBD mode but that only shows emission related engine codes so no help there either.

The front fuse box is labeled, the one in the trunk is not but I found fuse and relay postions online, although I have to be careful since locations can change per year of manufacture. I also found some good wiring diagrams of the starter circuit from the workshop manual but unfortunately it is just the starter circuit and not a complete diagram so I still can’t see where the pin that feeds 12V to the starter relay coil is connected to. I indeed found the ASD relay and I switched it with a known good one but it made no difference. Besides that I didn’t do any measurements on it so far.

Maybe someone on here has a good complete wiring diagram and is willing to figure out for me where the 12v feed to the starter relay control circuit is coming from? That’d be a big help.