Mercedes SLK World banner

1 - 20 of 84 Posts

·
* Registered 1998 SLK230
Joined
·
79 Posts
Discussion Starter #1
Lots of question to help me revive my cheap 98 230. I have slowed a little, but it is still not cranking, so here’s the update.

Battery load tested at shop, “solid battery”

K40 cleaned, soldered, all relays totally cleaned.

Pse removed as it was destroyed by rust.

Fuel pump runs when jumped, fuel rail showed pressure after super quick fuel pump test

Throttle body is getting electrify and buzzing lightly.

Starter motor engages and spins well when it’s jumpered at the solenoid. I removed plugs, gave cylinders 5cc of marvel mystery oil and then jumpered the starter and it cranked like it should.

Every electrical switch works. Seat warmers, all lights, horh,flashers, Heater fan... radio light is on, but have not got code yet.

Roof works after wire repair. Front cylinder need repaired which I will do

Any last comments before I end up towing to a Mercedes scanner?

Wish I had a K40 that I knew was good.


Sent from my iPhone using Tapatalk
 

·
Registered 1996 SLK230
Joined
·
219 Posts
A basic check. The fuel pump should run when you turn the ignition on. The relay is on the K40. Does the relay operate? (you might not have an air pump relay as you have a 230).
Awesome! None of those (to me at least) seem to have any relationship to the S/C, perhaps with the exception of #3. Would #3 be the correct one?
 

·
Premium Member 2002 R170 SLK V8 5.0
Joined
·
4,135 Posts
Did the Fuel Pump run when you powered the K40 Fuse like I asked ?

Do you have more than 1 Key, if so have you tried the other ?

Multiple threads are getting disjointed and confusing btw ;)

Drive Auth needs checking on SDS, I seriously think that with this Car you'd be better purchasing your own machine, you can easily waste your budget paying for diagnosis which is not full diag, please, whatever you do, if you take it to a Dealer or Indie, insist on getting a print out of the Full Test so we can see it, do this before you hand your Car over, many will say they cannot print or forgot, then all you are getting is a half assed 3rd hand opinion of what is wrong from a Service Receptionist :(

At the moment my gut is saying either K40 or Drive Auth issue, especially as you have now verified Battery and Starter Motor Circuits are good ✅ .................

Possibility that Ignition Switch, Clutch Switch or Auto Shifter (Start Inhibit) and / or Pulse Module has gone bad too, as that is all involved in the cranking sequence ;) ................

So here it is ...............

Key in Ignition >>> Turn On >>> Ign Switch sends 12V to Ign + Ckts >>> K40 Powers up Motor ECU and Fuel Pump Ckts via 2 of its Relays >>> Das RF and Motor ECU now verify Immo Data >>> Turn Key to Crank >>> Ign Switch sends Crank Signal to Motor ECU (some Cars have a Clutch switch or Auto Trans inhibitor) >>> (if Drive Auth is correct) Motor ECU now sends a "Crank It" signal to Pulse Module >>> Pulse Module now sends the 12V+ to Starter Solenoid >>> Starter Cranks Engine for about 20 seconds (or until it fires up)

............

Simples 🤣

Please tell me you are pushing the Clutch Pedal down if Manual, or can see P or N in Gear Display on Dash, that said the new WD's for your car do not show a Clutch Switch (I just looked)🤣

3rd PDF (1998 230), page # 64 here:-


OK, I think I covered all that :poop: now ;)

HTH;)
 

·
* Registered 1998 SLK230
Joined
·
79 Posts
Discussion Starter #5
Sorry for multiple threads. As I knock off an issue it leads me closer and maybe new questions/directions come up. Old posts seem to die. If I wanted, I would give up and go to get a scan, but not until I try. Forums are great for us trying to trouble shoot. What is meant by powering the K40 FUSE? 1 Key only, driven manuals for 50 years, so if it was a manual, I think that ones covered. This car is an auto and I have moved the shifter through the gears several times to make sure it is hitting home in Park, but switch could be bad i guess.

Fuel pump never comes on. Only when I powered it from an external power source.

With K40 out of the box, but powered up, connecting horn relay by touching the moving plate fires off the horn. Should it fire off the Fuel pump if I did the same thing to that relay?
 

·
Premium Member 2002 R170 SLK V8 5.0
Joined
·
4,135 Posts
SDS is not just a Scanner, it leads you through procedures to find the fault plus has much other S/W, I've written way too much on here about it to keep repeating it, use the search it's all explained on the Forum by myself and many others.

Getting the Car diagnosed properly with the correct machine is not giving up, it gives you more time with your friends and family and less headaches and expense ;)

You simply cannot work efficiently on these Cars without SDS, there will always be a job where you will end up chucking parts at it because nothing else will diagnose MB's correctly.
Proper diagnosis is not simply changing a part based upon a fault code alone !! Sometimes that will work, but on other complex issues like this it rarely works.

I could have diagnosed this Car within 2 hours using SDS, and I bet the fix will cost under £250 in parts.
I could give you a parts list and say "here change all of these and it will crank over", but that's not proper diagnosis and certainly not cost effective, "Parts Darts" we call that ;)
Once we get it Cranking, it might not start, but it very likely will if the Fuel Pump then runs.

Take a wire or power probe and hit the Fuses with 12V +, if fuses are good it doesn't matter which side you hit.

Pressing the Relay contacts doesn't mean they aren't bad, you may be pressing harder than the coil pulls them, however yeah may be worth a try.

And you didn't answer my question ...................

Can you see PRND displayed below the Rev Counter ? ..... If so does it change to the correct gear selected ?

Being an Auto, obviously we can completely rule out Clutch Switch now ;)

HTH :)
 

·
* Registered 1998 SLK230
Joined
·
79 Posts
Discussion Starter #7
I’m not frustrated yet!!. Just testing things as I get time so sds test doesn’t include simple things already contacted shop and will most likely will call for appointment after this weekend if needed . I’ve yet to spend $ other than maintenance items like plugs, oil, filters and some roof checks.

I assume you rev question means tachometer (rpms)? The only thing in the display under it is the time of day. Shifting when key is on doesn’t change it off of time. Relays will get tested tonight if I get off work early enough.


Sent from my iPhone using Tapatalk
 

·
Premium Member 2002 SLK320
Joined
·
807 Posts
It is possible to do some fault diagnosis without SDS (the old fashioned way) if you know how to use a voltmeter and read wiring diagrams. Wiring diagrams are here (see below). For instance, the fuel pump appears on page 24/73 of the 230 wiring diagrams. With the ignition on you should have voltage on the fuel pump. I assume you don't, so check the voltage at the K40. If no voltage, check at the fuel pump relay, and so on. Does the fuel pump relay operate if you put the ignition on?
Of course eventually (in fact fairly quickly) you get to a point where you need to know how things work in the logic of the circuit boards (among other things). That's when you have to have SDS. A generic code reader can help (a bit) but sometimes creates red herrings.

 

·
Premium Member 2002 R170 SLK V8 5.0
Joined
·
4,135 Posts
The only thing in the display under it is the time of day. Shifting when key is on doesn’t change it off of time.
It won't change off of the Time, it will (should) display the Gear Selector Position next to the clock on the left of it upon Ignition on ;)

That indicates a lack of communication between Transmission Controller (TCU) with the Cluster and ME ECU etc etc .............

So it may be that if it cannot see P / N Signal it will not release an un-inhibit signal, or it may just be that nothing is getting Ignition Circuit "ON" Power...........

This is how your Cluster should display indicated Gear Selection, Ignore the fact that my Cluster is different, they should all display the Gear Selected in the same place ....

(Pix are clickable)










1) Have you tried applying 12Volt Power to those Fuses on K40 like I asked, (ME Fuse and Fuel Pump Fuse) whilst Ignition is on, then see if it will Crank, and does the Pump now run ?

2) Does your dash have some or all of the Warning Lights come on like mine is in the first pic before I fired it up ?

3) You could also take out the TCU and carefully open it's casing, you are looking for signs of Oil

Report back when you have done at least the first 2 items above that I asked for, we are still making progress, if you do as I've asked and report back I can then advise you further ;)
We might get this to run yet without SDS ;)

HTH :)
 

·
Premium Member 2005 SLK200K 'Little Growler'
Joined
·
1,239 Posts
It won't change off of the Time, it will (should) display the Gear Selector Position next to the clock on the left of it upon Ignition on ;)

That indicates a lack of communication between Transmission Controller (TCU) with the Cluster and ME ECU etc etc .............

So it may be that if it cannot see P / N Signal it will not release an un-inhibit signal, or it may just be that nothing is getting Ignition Circuit "ON" Power...........

This is how your Cluster should display indicated Gear Selection, Ignore the fact that my Cluster is different, they should all display the Gear Selected in the same place ....

(Pix are clickable)










1) Have you tried applying 12Volt Power to those Fuses on K40 like I asked, (ME Fuse and Fuel Pump Fuse) whilst Ignition is on, then see if it will Crank, and does the Pump now run ?

2) Does your dash have some or all of the Warning Lights come on like mine is in the first pic before I fired it up ?

3) You could also take out the TCU and carefully open it's casing, you are looking for signs of Oil

Report back when you have done at least the first 2 items above that I asked for, we are still making progress, if you do as I've asked and report back I can then advise you further ;)
We might get this to run yet without SDS ;)

HTH :)
Nice looking clocks Dave :)
 

·
* Registered 1998 SLK230
Joined
·
79 Posts
Discussion Starter #11
* No sign of a gear indicator near clock in any gear. See pic

No fuel pump sound with 12 volts to fuse



When f2 was removed, sound under air filter stopped (air pump)

When f3 was removed, radiator fan went on high

Tcu is oil free but there is a wire with a bare spot. See pic.


Sent from my iPhone using Tapatalk
 

·
Registered 1996 SLK230
Joined
·
108 Posts
@Dave2302 FWIW I have (for some unknown reason) a post-FL cluster in my pre-FL 230. I get no gear display showing up at all, ever. The car runs and drives great, changes all gears properly, but I don't think pre-FL cars had gear indicator on the cluster. Just like we don't have the +/- on the gear selector.

Cheers
Jay
 

·
Premium Member 2002 R170 SLK V8 5.0
Joined
·
4,135 Posts
OK, great call guys, thank you ..................
So Pre Facelift don't got Gear Position :(
I didn't know that, something else learned, shame tho, because I thought we could be onto something there ;)

Make certain that damaged wire is still intact and insulate it, time to move on .....................

Ring out the wiring between the Fuel Pump wire at K40 and the Pump itself, they are known to get bad wiring near the fuel pump end, perhaps where it goes in through the grommet ;)
Have you tried just Earthing the Earth at pump, does it run then ? ................... In other words is it missing it's Earth or it's +ve ;)

However, I seriously doubt that is causing no crank :(
I'm really busy right now, will see if I can get a look at the Wiring Diagram for the 4 cylinder in the new WD Sticky, but don't count on it, take a look yourself at where the Wiring goes after K40 ;)

You have now almost certainly ruled out the K40 as the noises stop and fan starts when f2 and f3 out which means we can be pretty certain the ME ECU is getting power. ;)

This is looking very much like we are getting down the Drive Authorisation (Immo) Path, but I don't think the Drive Auth shuts off Pump, only Cranking and Firing certainly on later cars ;)

I'm almost tempted to see if you would rather spend SDS money on a "ECU / Key(s) / DAS RF Module matched set" from another Pre Facelift 230 and plug 'em in she might just start up then ...........

Like this one :- MERCEDES SLK 230 1996 - 2004 ECU A0285457832 IGNITION LOCK IMMOBILISER KEY | eBay

However check the ECU Part Number is the same as yours, or listed in EPC as a suitable update. Get one from USA as well as I think the Keys use dirfferent RF Frequency for the C/L

Note that you can swap the key blade from your existing key to the "new" fob so you don't need to change all the locks, just plug in the ECU, and DAS RF Module put Key in and she should start and crank ;)

HTH ;)
 

·
Premium Member 2002 SLK320
Joined
·
807 Posts
Hmmm. I always thought that if Drive Authorisation (Immo) is not working we get an "Start error" message in the instrument display. Am I wrong? Or is this something else that the pre-facelift doesn't have?
 

·
Premium Member 2002 R170 SLK V8 5.0
Joined
·
4,135 Posts
I know for a fact even the later ones have a version coding so if coded not present not all late ones have that message, so I doubt the earlier PFL cars had it ;)

If someone with pre facelift wants to prove it categorically, pop the key blade out of the fob, stick the fob in your house, (well at least a few metres from the car), and switch Ignition on with just the blade, see if you get start error ..................

Still doesn't mean that its coded to work on OP's Car tho, all Cars I've checked also have a Version Coding that turns the EML so it doesn't ever come on ;) .............

HTH ;)
 

·
* Registered 1998 SLK230
Joined
·
79 Posts
Discussion Starter #18
Great help

If I go the used part way just clarifying

Matched das,ecu and key fob with chip is the setup needed as long as it matches my part numbers? Us prices are a little higher, around 400 us.

Isn’t key part néeded that matches key chip?

Sent from my iPhone using Tapatalk
 

·
Premium Member 2002 R170 SLK V8 5.0
Joined
·
4,135 Posts
Matched das,ecu and key fob with chip is the setup needed as long as it matches my part numbers? Us prices are a little higher, around 400 us.

Isn’t key part néeded that matches key chip?
Yes, when I say matched, I mean that they all came from the one good running car, thus they have already all had the initial start procedures done, they are now locked, (cannot be re programmed) but all "shake hands" Immobiliser speaking, with each other, meaning the car will start. The Key Fob's Chip is matched to DAS / RF Module which is matched to ME ECU, they are the three "Theft relevant Components".
Part numbers wise, you need to use EPC to look up all ECU Numbers that will fit your particular VIN Number, there may be several with slightly different p/n's that will work OK.

The Key fob is the bit with the Immo Chip in it, as well as the separate circuit board for the RF C/L, that Chip is what matches the Immo Data, so to avoid changing all your locks you can swap over the actual metal key blade, must use the fob (bit with the buttons) that comes with the set you buy ;)

If you have to have just one module, (ECU or DAS / RF) replaced with brand new, only MB can do that, possibly a good indie if MB will sell him the parts, (they won't sell theft relevant parts to general public), but if you have to have say an ECU replaced it will cost over $1000 just for the part then plus labour to fit and program it ;)

The only one slight issue is that if you use a used matching set it will of course report the Donor Cars VIN on Diagnostic Machines rather than your actual VIN ....................
No biggie, just be aware, someone as anal as me wouldn't like that, but then again I now have the knowledge and tech to Virginise an Engine ECU and then clone it to the car concerned, same with DAS / RF although that is a lot harder to Virginise and more risky to brick it ........................

You don't have to worry about all that, just fit it all and it will start, assuming the Drive Auth is the issue, which it certainly looks like it is, but only SDS can absolutely confirm that ;)

In a nutshell if this is a Drive Auth issue, my post # 15 above is the cheapest way to get you going, and a fairly easy plug and play DIY ;)

The hardest bit will be taking the Cluster out to get at DAS / RF Module, which is sat behind it on the Bulkhead above the Steering Column ;)

HTH,
 

·
* Registered 1998 SLK230
Joined
·
79 Posts
Discussion Starter #20
This weekend will give me an answer. Matching Ecu, immobilizer and key will be here and I’m nervous that it will work. Tcu wire fixed, all put back and entire dash is out awaiting immobilizer I should stop messing with it till it runs but I can’t. Fresh oil, filter, plugs, cleaned it up a lot. Polished headlights, new trunk struts...... it better run


Sent from my iPhone using Tapatalk
 
1 - 20 of 84 Posts
Top