Erratic Sam board behaviour

[Tonybee 0]

Hi this my first post so be gentle. I bought my daughter a 2006 fortwo city-coupe passion 42000 miles and it has run fine for the first month then after self isolating for 2 weeks first run out the lights cut out and things like rear heater button light wouldn’t stay on(in fact that was the first symptom I noticed) we called the aa and he put a battery booster on which meant we could drive home with lights on. The rear heater light still wouldn’t stay on though. There are all sorts of relay sounds happening from the Sam board and the gearbox is working intermittently. I have read that moisture can cause problems with the Sam board and I’m also wondering if it could all be down to a bad earth. The aa man said it was alternator but after charging the battery overnight and it not taking a charge I have replaced battery but the issues are still present. One question I think I know the answer to is, is the Sam board a swap out part? (I’m guessing no) thanks in anticipation.

 

tony

Edited December 2, 2020 by Tonybee
Grammar

[MikeT 744]

SAM requires a re-coding to the car's VIN in the STAR system or something similar.  Before changing it, investigate the reason it failed - specifically windscreen leaks.

[Willys 747]

Welcome to the site.....
Read all threads regarding the SAM and follow all bad solder joint posts and fixes. Also burnt up connectors from same row of 10 pins common to this issue.  The SAM must be reprogramed with a STAR system if you wish to swap it out. That goes for all 3 of the cars computers. Never touch any electronics unless you first undo neg earth off battery. I fried my ECU computer which lives on the righthand side of the air box by simply washing the corroded pins using sensor cleaner and a toothbrush type brush, it simply shorted or discharged a capacitor inside the ECU and it was junk afterwards. Yes check all grounding pins everywhere and there are many. They all look perfect until you undo them and then you'll perhaps see the white or green corrosion between the bad ones. Then go after the white plug in the battery well also as it may be well corroded, another typical issue. BUT, check the SAM first, take it apart carefully, unwrap the board and check the row of 10 pons using a head magnifier as the damage is sometimes very hard to see. Other times it's very bad. and requires carefull surgery but usually can be repaired all depending upon your soldering skills.   There are plenty of threads on this subject....so do some simple researching before taking the car to a shop. IF you can work a multi meter and simplish tools .....oh and have small hands you can work on this little car.  Everything is torx tools for the most part so start purchasing those if you want to do the work.

Again welcome......enjoy there is plenty of help here.

Also spend the smallest donation to Evilution.uk.co as they have excellent technical knowledge but it's a bit difficult to navigate around but once you do it is jam packed with good info with excellent pictures also.  BUT it's not a chat type site, all tech so use it to get that then come here to get a human for help.  Both sites combined will give you everything you need IMHO.

 

[Tonybee 0]

Thanks for the quick reply willys. So what I mentioned sounds like it is more likely to be the sam board and not the alternator? I didn’t mention that the gearbox also started to behave erratically too. Not changing gear properly in forward auto, could this be caused by a problematic Sam board? I have read that the gears are controlled by computer and so it can be an issue. Also from what you’ve said is it easy to disconnect and reconnect the Sam board plugs and simple reconnection? No confusing plugs or such to watch for?

[Nigel 287]

Check the alternator first.  It’s easy and free.  If you have a multimeter check the battery voltage and then start the car and check again.  If the alternator is doing it’s job the voltage will be  higher around 14 to 14.2 when engine running.  No meter turn on the key and the headlights note the intensity and then start the car.  The lights should be brighter when the engine is running.

I think you have too many problems at once for it to be the SAM unless it is a power supply or grounding (earthing) issue.

 

Just my opinion but I’m not a mechanic.

 

Nigel

[asl3312 8]

The alternators are in an exposed position in the lower wheel arch and it's common for them get full of moisture being thrown up from the road and seize up, particularly if the car is then left standing for a while. I'd be looking in that area.

[Tonybee 0]

Thanks Nigel. So last time I checked before turning the key the fan worked and the rear heater then I started engine dash light on at first then dash light went off also headlights not working. Going to check the Sam tomorrow for any obvious signs of corrosion etc. Any more thoughts on alternator being the issue would be appreciated. I have a multimeter but I’ll be honest I don’t know how to use it and where on the alternator I would place it. I have an engine light on so I’m going to check code tomorrow also.

[asl3312 8]

1 minute ago, Tonybee said:

Thanks Nigel. So last time I checked before turning the key the fan worked and the rear heater then I started engine dash light on at first then dash light went off also headlights not working. Going to check the Sam tomorrow for any obvious signs of corrosion etc. Any more thoughts on alternator being the issue would be appreciated. I have a multimeter but I’ll be honest I don’t know how to use it and where on the alternator I would place it. I have an engine light on so I’m going to check code tomorrow also.

Check the alternator output at the battery itself.. engine not running should be around 12V.. with the engine running it can range from 13.5 - 14.5V.. but should obviously read higher voltage than when engine is stopped.

[Tonybee 0]

Thanks asl3312 I’ll take a look. The aa man said they can throw the belts too but it hasn’t. If it’s seized I guess it would throw the belt. Keep the suggestions coming. My daughter had a rough year last year with issues with her eye and has decided to learn in an automatic to make life easier. Hoping to get her back learning ASAP 

[Tonybee 0]

6 minutes ago, asl3312 said:

Check the alternator output at the battery itself.. engine not running should be around 12V.. with the engine running it can range from 13.5 - 14.5V.. but should obviously read higher voltage than when engine is stopped.

The aa guy said he couldn’t check the battery or alternator because it was drained 🤔 so what setting would I put the multi meter on?

[asl3312 8]

10 minutes ago, Tonybee said:

The aa guy said he couldn’t check the battery or alternator because it was drained 🤔 so what setting would I put the multi meter on?

Voltage DC or VDC. Put your red probe on positive (+) battery terminal and black on negative (-). You should have the readings I quoted earlier.

Edited December 2, 2020 by asl3312
More info

[Willys 747]

The SAM issues are well documented and do some simple searching here and also over at the other site I mentioned. BUT over there you won't be speaking to anyone, you will be doing all the searching yourself. That is why you ask here then IF we do not have the pretty pictures etc and excellent description of what is asked you go there. It is well worth their smallest donation fee. Trust me.  lol. Seeing a picture can open one's eyes far easier than trying to understand someone else's explanation of the same thing.

OK, here we go....

First check all grounding pins and that includes the larger battery ground at the battery and then also the main engine to body ground as that will in time disintergrate. Literally!

Second: While you have the battery disconnected looking at the ground connection, take down the SAM unit from under the laft under dash location. You push up and back at the back then unclip the front,or is that the other way, either way Hmmm...?  I should know by now I've had many down...lol.  Remove all connectors, they all only fit in one spot, so no fear of mixing them up. The back two larger plugs have an up and over clamp holding them down. Then you have a 10 mm hex head nut holding down the main power cable, red. You now have the side fuse holders that need a small screwdriver to carefully unclip the tabs. Now it's free.  The body is held together with 3 very small torx screws, hense you'll need to get some torx screwdriver bits or a cheap set. You'll need them for all small screws on the car.  Then you'll find numerous tabs holding the body together, they snap easily BEWARE.  Once they are unlatched open case, now you'll find a few internal clips or posts holding the circuit board in the case. Once the board is out it unfolds releasing the other hard plate, now carefully unfold it and get your head set magnifying glasses on to see the burnt or cracked solder joints on a row of 10 pins. They will be the only row of that size and easily obvious if in bad condition. IF they are in bad condition you now have two options depending upon how bad they are. IF just a crack around the pin as in a cold solder joint. You'll need desoldering braided wire to remove the solder or a solder sucker. You should use a hot soldering iron not the cheaper old school versions. The newer irons get far hotter and easily melt the solder to get all of it out. Now I use acid cleaner then resolder making sure not to burn the board or add too much solder to bridge two pins.  Now if the pins are seriously burnt up and the damage traveled to the connector pins maybe you need to solder wires to the pins we just spoke about and bypass the circuit board and send wires directly to the connector or past it to the wiring harness itself..?   It has to be seriously bad to not be able to repair it if you can operate a soldering iron correctly.  The SAM doesn't control everything, remember there are 2 more units that you need to check, one the speedo but it rarely cooks itself then there is the ECU on the righthand side of the airbox. This ECU contains capacitors that hold a charge and will discharge if upset so BEWARE! The inside may have some water staining but rarely so. It'll be the two larger plug ins that will have 3 pins corroded. Again BEWARE!  IF you cook it you will be forced to buy a good used one or new, then you will need to have someone reprogram the new one so it will speak with the car's original other 2 units. The SAM and the Speedo.

Third: Check in front of the battery in the battery well for that white plug. I know of only one that wasn't in need of replacing and that is Nigels....strangely enough, we live in the same area!

Forth: The gear select motor has a wiring harness that gets rubbed through where it travels over the inter cooler scoop, this buggers up it's signal and it may need a reteach for the transmission, again a STAR system job?

Fifth:The actuator could be well out of position and require cleaning and correctly installed firmly against the shift fork  to operate correctly.

 

I'll stop here and let you check these first and check the battery as described above. The alt. will get full of road crap as the clearances around it's shield is imho too tight as is all clearances to be able to easily work on this car....lol. When you are ready to get serious about working on such things as starters, alternators, thermostats, glow plugs, injectors, etc etc....that will be the time to start thinking about lowering the subframe or should I say lifting the body away from the sub frame to make working on this car far far easier. It takes 4 bolts undone and it can be easily lifted 8 inches for far more room to work. 

 

Have fun and if you need more info just ask...lol.

I'm not sure but if you can go to the WIKI section and look at the pictures of my engine rebuilding  and you can see where things are located in relation to other things, which may help you find things or allow you to work blind, by touch as you will not be able to see things if you do not lift the body.  But you may need permission to get to that forum....untill so many posts?   I don't know. IF you need permission and want to see the pics, ask Smart142 as he's a mod.

 

[Tonybee 0]

So here’s an update I didn’t mention that when I went to the smart yesterday morning with the new battery the car wouldn’t unlock I assume this was because the old battery was dead. So I fitted the new battery yesterday and at first many things were ok as I said but it didn’t take long for things to stop working. Anyway I went to it again today and wouldn’t open again with remote so had to climb in the back to open door again. To me this sounds like something is shorting. I’ve removed the battery and put on charge and I’ve also removed the Sam unit and opened it up and given it a good look over with a magnifier and everything looks clean and as it should. I haven’t been able to find my voltage meter so haven’t checked the alternator. Could that be shorting out even when the car not running? That doesn’t sound right.

I’ll be honest this has happened at a bad time for us as we lost my mum to covid a couple of weeks ago and obviously we’re all dealing with that. Just want to get it back on the road and put a smile on my daughters face. I was really hoping something obvious would present itself in the Sam unit. as always any suggestions greatly appreciated. Thanks Tony

[Willys 747]

Sorry for your loss....

You can't test anything until the car's battery is perfect....until then you won't find anything so to speak wrong electrically speaking. You as said above must have 12 or above volts showing on the battery, then also a good fob battery etc. Both can be checked using a dirt cheap 5 pound multi meter  they are close to $10 here for the very very basic crap and that will do the trick, but spend more and get a slightly better one sensibly speaking. 20 pounds...lol.  You check both batteries the same red to positive black to negative and if they each do not show what is written on battery or very close to it they are no good.  Start there.  Find a picture of the SAM and see if your SAM is the same as the pics both good or bad. 
Let us know and we'll move forward.

 

[Tonybee 0]

Thanks willys.

 

went out to flat battery again. 

So alternator is fine charging 14v. Symptoms have now levelled off to when pulling up relay in Sam clicks and everything comes on and as soon as you pull away all clicks off. Also slightly worrying there was a small amount of smoke coming out of the battery. It sound to me like something is shorting but of course that could be something in the Sam board I guess. Is it sounding like a job for an auto electrician?

[Tonybee 0]

Thanks willys.

 

went out to flat battery again. 

So alternator is fine charging 14v. Symptoms have now levelled off to when pulling up relay in Sam clicks and everything comes on and as soon as you pull away all clicks off. Also slightly worrying there was a small amount of smoke coming out of the battery. It sound to me like something is shorting but of course that could be something in the Sam board I guess. Is it sounding like a job for an auto electrician?

[Tonybee 0]

Battery tested 12.8v ignition off then 18.28v with engine running. Would that indicate the alternator is overcharging?

[Nigel 287]

Yes.  Could be a problem in the alternator killing the battery when engine off as well.

 

 

[Willys 747]

Hmmmm.....so the whole thing started with a drained battery. No new alt so no-one messed with wiring. So rear main power line isn't shorted from someone doing a bad install. So the Alt wasn't siezed and turned well when hand or wrench turned? After taking belt either off or by turning engine also? So if alt is turning, it should be OK...fingers crossed?  Next i would see if main power is shorting to body with cable off battery neg. So put positive of multi-meter on pos of battery, and black neg of multi-meter on ground pin on body of car or ground wire that normally is attached to neg on battery but isn't attached. See if you get a reading on the multi-meter of any kind on the 12V setting DC setting.  IF you do you have a dead short somewhere. Next I would be taking SAM apart again and please take pictures and post them here of all sides of the board all over as close as you can get clearly. please.  We know what to look for and can hopefully spot your issue? 

OK after re-reading the entire post 3 times you never state whether or not you have lowered the SAM and taken it out. You NEED to do this, it is easy.  Maybe not the first time but afterwards simple. It lifts up and unclips at the back then the front, back being the front of the car but seems the other way when head under dash.  Until you do this you will NEVER know what is what. IMHO.

Take pictures and post them. then we can see what's happening beter to help.

 

[asl3312 8]

19 hours ago, Willys said:

Hmmmm.....so the whole thing started with a drained battery. No new alt so no-one messed with wiring. So rear main power line isn't shorted from someone doing a bad install. So the Alt wasn't siezed and turned well when hand or wrench turned? After taking belt either off or by turning engine also? So if alt is turning, it should be OK...fingers crossed?  Next i would see if main power is shorting to body with cable off battery neg. So put positive of multi-meter on pos of battery, and black neg of multi-meter on ground pin on body of car or ground wire that normally is attached to neg on battery but isn't attached. See if you get a reading on the multi-meter of any kind on the 12V setting DC setting.  IF you do you have a dead short somewhere. Next I would be taking SAM apart again and please take pictures and post them here of all sides of the board all over as close as you can get clearly. please.  We know what to look for and can hopefully spot your issue? 

OK after re-reading the entire post 3 times you never state whether or not you have lowered the SAM and taken it out. You NEED to do this, it is easy.  Maybe not the first time but afterwards simple. It lifts up and unclips at the back then the front, back being the front of the car but seems the other way when head under dash.  Until you do this you will NEVER know what is what. IMHO.

Take pictures and post them. then we can see what's happening beter to help.

 

The alternator is not ok if it's putting out 18V whilst running. This would definitely be my starting point in diagnosing this issue.

[LooseLugNuts 557]

get the alternator checked

 

it probably has bad diodes 

 

dont run it at 18v anymore 

[Leadwing 565]

Mine runs at a steady 14.8V when running.  IMHO, it shouldn't be much higher than that.  BTW, a smoking battery is NOT a good thing.  Until you determine what the smoke (gas) is don't have any exposed flames or sparks near it.

 

[Sydney 218]

before you dive into too much with the car,  just remove the alternator and have it tested.  18v is probably a bad alternator which overcharged and ruined your battery.

[LooseLugNuts 557]

5 hours ago, Leadwing said:

Mine runs at a steady 14.8V when running.  IMHO, it shouldn't be much higher than that.  BTW, a smoking battery is NOT a good thing.  Until you determine what the smoke (gas) is don't have any exposed flames or sparks near it.

 

 

its most likely hydrogen

 

thats why interior batteries have  vent hoses