Bewildered

ESP light and engine power cut

60 posts in this topic

3 minutes ago, LooseLugNuts said:

i might be reading wrong or using wrong diagram but those pins appears to be for wipers/

 

 

https://www.fq101.co.uk/how-to-guides/fortwo-450/electrical/251-sam-wiring

I concur - pins 10, 11 & 12 (at the other end of the bank) refer to ECU.

 

I’ve had my trusty multimeter out and checked continuity from the plug side of the connector all the way to the other end of the “track” whilst waggling the multiplug - no joy... all fully continuous and not affected waggling - the resistance doesn’t change.

I have my soldering iron out.... should I give them a dab of solder just to make sure?

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yes...go over anything suspicious..it wont hurt and might help (unless youre a butterfinger)

 

id say use proper flux and a very fine tipped iron but i have a feeling you already doing that 

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35 minutes ago, LooseLugNuts said:

looks like broken solder to me

 

id resolder all 5 of those pins above...especially that 5th one 

I agree....now i have seen them.....typical issue.

 

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IMHO, better to desolder them using solder sucker or solder brass wire that sucks solder out of pins then clean and resolder using correct solder.....

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Mercedes solder is very high temp.... I’ve had to put my iron up to 480C to suck the stuff out!!!!

All N11-5 pins re-soldered.

Is there anything else whilst the SAM is out?

I’ve done a visual check - but you guys know the problem areas!

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7 minutes ago, Bewildered said:

Mercedes solder is very high temp.... I’ve had to put my iron up to 480C to suck the stuff out!!!!

All N11-5 pins re-soldered.

Is there anything else whilst the SAM is out?

I’ve done a visual check - but you guys know the problem areas!

I would check every pin on the sam on that side of things, looking for exactly what you have seen on that row of pins, it can be a simple blackish line not even a break to the eye, but after the circuit gets warm it expands and then loses connection.   There may not be anything but until you rule them all out you'll be simply redoing the work for a few minutes of searching...IMHO.

 

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Can you take good pics of the resoldered pins.....it's easy to not get a good flow to get the solder to stick to the pin

 

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Looks bad to me too. Can we have another photo or two please  Higher magnification if at all possible. 

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going back to your first post.    you say the ESP light comes on and you loose all power.

does the ABS light come on also?

Edited by Sydney

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OK you are going to hate me, I see 3 bad solder joints now.....going from left to right 1,8,11  You need to get the old solder complete out of joint then apply new solder, that is why I suggested solder sucker in one way or the other...sorry.....and a dab of acetone to clean if any residue is left....

 

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14 minutes ago, Bewildered said:

Just the /!\ light.

not to pull you away from the SAM,  but it think your problem is elsewhere. 

i had the same problem about 8 months ago.   while i was driving along,  my traction control /!\ light came on and i lost power.    (the only difference was my ABS light came on also)   

i shut the car off,  started it back up and continued on my merry way,  untill it happened again and again and again....   had my car towed home   (sound familiar)...

turns out my problem was a spread pin on the harness going to the clutch actuator. 

i cleaned and fixed the harness and the problem never came back.

the traction control system cuts power to your engine.    this would also explain why you car will idle and rev while stationary with no problem.

 

 

Edited by Sydney
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I think it’s my photography rather than soldering !

The old solder was sucked out, pcb flux was then applied and new solder replaced.

Please don’t think I’m ignoring you - I’ve got to go away for today, but will be back tomo around 10:00 (16.5hrs away).

As soon as I have better photos I’ll post.

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Hi Sydney
Thanks for joining our merry party 🎉

That is (pretty much) exactly the problem I’ve been having - unfortunately for me, I’ve replaced the actuator and the loom (both from a working car) so I know (for sure) that they are not my problem 😟

Did you find anything else askew with your car? Anything you might consider inconsequential? I really am grabbing at straws!

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The other difference between our issues is the restart time-lag. If I restart immediately the car engine won’t start easily and won’t tick-over. If I “Left-foot” the brake to keep the gas on with my right and then try driving the /!\ comes on and everything dies. I can do this many times, but if I want to drive any distance I have to wait 10 / 15 mins.

By “any distance” I mean 4 or 5 minutes!!

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1 minute ago, Bewildered said:

The other difference between our issues is the restart time-lag. If I restart immediately the car engine won’t start easily and won’t tick-over. If I “Left-foot” the brake to keep the gas on with my right and then try driving the /!\ comes on and everything dies. I can do this many times, but if I want to drive any distance I have to wait 10 / 15 mins.

By “any distance” I mean 4 or 5 minutes!!

Just enough time to heat up those bad solder joints and create a gap....maybe...lol.
I hope we find your issue for you, it's good to be able to work together to solve things for one and other......far better than keeping the tricks of the trade to yourself so to speak. No-one benefits doing it that way.   Fingers crossed.  Best to try it after this resoldering then rule out the SAM.

 

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I’ll get my camera out tomorrow rather than using phone camera.... that way I can manually focus and give hi-res images.... up to 2MB anyway !!

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i never kept track of my restart time.  i know it wasn't right away.   and as for the driving with your foot on the brake...  have you tried doing it with your other running smart?   i think the car is designed to cut the power when you try to do that.

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25 minutes ago, Bewildered said:

Hi Sydney
Thanks for joining our merry party 🎉

That is (pretty much) exactly the problem I’ve been having - unfortunately for me, I’ve replaced the actuator and the loom (both from a working car) so I know (for sure) that they are not my problem 😟

Did you find anything else askew with your car? Anything you might consider inconsequential? I really am grabbing at straws!

no,  i didn't find anything else that i can think of.   sorry.   but luckily my problem never came back. 

 

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Hi Sydney.

I hear what you’re saying. The procedure hasn’t been tried in the working car.

The only reason for touching the brake pedal is to get the car into gear. Once the car is moving the brake is released. It’s ok for a couple of hundred metres, then the /!\ light comes back on, the accelerator fails to respond and therefore (as the engine won’t tickover) it dies. As soon as the accelerator is released - the car dies.

Once the engine is dead, I have to stop the car in order to restart the engine.

Left foot on brake to go to neutral to start engine. right foot on gas to keep revs up ‘cos it won’t tickover (or start) without revs.

Left foot still on brake to go into gear then release brake and just use gas.... 200m (or so) /!\ light comes on, accelerator doesn’t respond.... etc. etc.

The only way out of this loop is to wait much longer before restarting - 10 to 15 mins... or so !

I’m really glad it didn’t come back for you - and I’m very grateful for your suggestion. Sooner or later something will stick :-)

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well,  i will be following along and i hope you find your problem.

the one thing that really find puzzling is that your car will run fine and rev without any issue when its not moving.

that alone would still steer me to say it has to have something to do with the trans, shift motor, clutch actuator,   (even though i know you checked all that).

what about an aftermarket cruise control? 

anyway,  cheers and good luck

 

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7 hours ago, LooseLugNuts said:

looks like broken solder to me

 

id resolder all 5 of those pins above...especially that 5th one 

I agree

Also if the sam has been replaced it my have gad this issue before check the plugs that connect to the Sam for corrosion

Edited by BWM
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Hi all, I’m back!!!

I have some much better photos, but they’re still not great - and the 2MB limit is a bit constraining.

1729F593-0028-4774-8A1C-5457A3CB8173.jpeg

C1F01A76-B02B-43AA-BD75-5AF9F80D7E4C.jpeg

1FA0CA38-0614-45C2-8EAC-3750943E3A2A.jpeg

0D83FB0C-8320-4A12-B70D-7D94F4518979.jpeg

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