gibbogibbo

Story is I have an S430 that was sitting a while and battery went flat. Couldn't get into the boot/trunk with the key as lock seized so only way I cold figure to get 12volts into it was to connect 12volt supply to the red cable running into the SAM on the right side under the bonnet.
Sure enough central locking worked, battery charged and car started and ran fine for maybe 90 secs then cut out.
Now the ignition key will turn, dashboard lights up, but not a hint of the starter engaging, the radiator fan spins up really fast though.

Any thoughts would be greatly appreciated. Can't get it on a trailer as the suspension is down
Thanks

ibeforreal

I would start with the battery. Although it may have started to car after being charged it still may not have enough power to run the car. Take the battery to a place an have it tested.

DanCV12

from it sitting for so long the battery could be completely dead. even if you charge them up to the full potential they will drain and the car will die. have the batteries tested. if they are good i would test the alternator next. if both are good start looking at wires, fuses and relays. depending on where your located and how long the car sat for could play into also. Some wires could have corrosion on them and its not making a good connection to the starter, starter is stuck and wont engage things like that. do a good once over on the complete starting system and we can go from there.

tusabes

No start and fan on high indicates bad ecu

I'm going to say there was standing water , probably in the reservoir under the windshield , that caused the damage

So when you started it and applied power you shorted out the wet electronics and fried the ecu

gibbogibbo

Thanks for the replies. I'd feared that I might have shorted something in the SAM but when it ran for 90 seconds I thought I'd got away with it.

I'll try a new battery, but I'd read somewhere that the fan being on fast indicated fried ecu or sam, just wondered if anyone had a simliar experience?

rik881

Send ecu in for repairs.

tusabes

If you don't fix the water damage first you'll fry the new ecu you put in It

gibbogibbo

Anybody had the problem of the fan spinning but no starter before?

rik881

I did and i spent many, many hours searching this very forum for a solution. You might want to use the search function. I fixed it myself as you will read in another topic. Here's the link: https://mbworld.org/forums/s-class-w...roblems-6.html

cybertronicify

Your cooling fan PWM pin is directly connected to the ecu, and if that fails, you either get full fan no fan or somewhere in between. But when you turn the key, what happens? If theres nothing then you definitely water damaged a main module, SAM or the ECU.

The w220 has a famous problem of getting a drain hole clogged and the water spills over into the SAM and ECU modules. Then electrolysis kills them, hence why it worked for a bit.

Go see if the port is plugged, if it is 99% water damage. The drain port is on the passenger side, where the blower motor intake fan is. Get a flashlight and look straight down and you should see a port. If all you see is leaves and debris then theres your problem.

BTW i'm guessing this is a left hand drive car.. So go and fold back the carpet on the passenger footwell, take the styrofoam off and take the metal plate off. You should see a square black box, take that out and open it up, check all the fuses and visually see if any electrolysis has taken place. Do so with the battery disconnected of course.

tusabes

Here is where you look for water and clean the drain , right under the windshield

gibbogibbo

Thanks for posting the link to your story rik881, read it all with great interest, pleased you got your car working after all the effort you put in.
And thanks tusabes for the photo.

I am in Ireland so plenty of rain and water around here! I will check the drain holes, but after taking the cover off the SAM/ECU/fuse box on the right side of the car, the lid had loads of condensation in it. Dried it out, but thinking I will send off the SAM and ECU to get them checked out. Will have to sort out the water problem.

It's a RHD by the way

rik881

No need to send the sam, just the ecu will do. A second hand sam with same part number should do it. I paid 50$ for mine. If you have another ecu with same part number you can just swap the immobiliser chip. Mine is RHD as well.

gibbogibbo

Well you guys were spot on, water damaged ECU, when it was removed I could see the ingress on the connectors and on the plugs.
Have cleaned out the scuttle drains which were indeed blocked and there was a lot of condensation around the ECU area

I watched the videos of swapping over the Immo chip from the old to a replacement one.

Is there anything else that has to be coded into the ECU or is it just this immo chip for it to work?

S430 RHD
1999 - UK spec

Thanks for all your advice

rik881

Just the immobilizer chip, you need to have same part number for the ECU. Good luck!

gibbogibbo

Well slowly but surely I got a replacement used ECU and had a guy transfer the data across from the faulty one as I wasn't confident about removing the Immo chip myself. Cost equivalent of $50 for that.
Just got ECU back last evening, plugged it all back in and turned key, starter kicked for half a second, and stopped, same thing happened every time.

Plugged in OBD2 cable and ran scan on laptop and cleared codes.

Turned key again and wow! it was great to hear the old girl fire up again. Running nice now. Only problem now is one rear side not coming up, will persevere as it was ok a few months ago, so hoping nothing degraded in a relatively short time.

Thanks again for all your help, you pointed me in the right direction and helped no end.

wallyp

Did you pull the carpets and padding and thoroughly dry all of the wiring under there? If not, you will eventually have serious problems from corrosion.

gibbogibbo

Still can't get the car to raise on all 4 corners, rear right as looking from the front isn't showing any sign of moving up. No hissing noise from that corner.

It was fine until it got parked up before the ECU problem, and has sat there for about 3 months.

I've searched and see the valve block is located on the compressor pump, is there a rear axle valve which distributes the air to either rear strut or is it piped to each strut straight from the valve block on the pump?

If I undo the correct fitting from the valve block for the strut that wont rise, and use low pressure compressed air straight down the tube to see if the strut rises, will I cause any problems?

The height sensor is working ok on the non rising strut as warning on dash goes off if I jack that corner up a bit.

wallyp

Left/right is always as seen by a seated driver.

Each of the four struts is pressurized by a direct line from the valve block.

There is only one height sensor for the rear, but one sensor for each front strut.

In order to reduce chances of damage, each strut should be partially expended before being pressurized. In other words, if the car loses all pressure, it is better if you jack the car on all four corners before activating the system.

Sclasspusher

Hello I'm having the same problem who did you have to do your ecu work?