OZCLK430

Hi All,
This is my first post under the username, somehow my old account will not work...

My problem is I have a 1999 CLK430 ( Australian delivery), that will not crank.

Indications are
1. Key works
- unlocks doors
- goes into ignition lock, and steering lock reads key and unlocks steering.
- turns to position 1, Instrument panel lights etc.
- turns to Position 2 and 3, but engine will not crank.

2. Small "Gear indication" block remains a solid block - ie no P, N, R, D indictation, even when the gear selector is moved.


I have an electrical engineering background ( i know - dangerous) but extensive auto backgroung as well (so only somewhat dangerous)

I have removed the shifter mechanism, all looks fine, cleaned both circuitboards.
I have removed the TCU ( transmission control unit) and inspected it including connections, all looks good
I have removed the cover from the start relay ( under the hood) and I can manually activate it and the car starts.

Its been over 9 months now ...ANY thoughts before I roll it into the yard and burn it ???

HWYSTAR

Was a mustang guy so this would indicate to me replacing the starter relay may do the trick. Although I am unfamiliar with these cars as I am a new owner myself.

OZCLK430

How bizarre. Ex mustang owner too in fact still have a 67 coupe in the shed.

Yeah not a starter issue

HWYSTAR

Yup 88 notch in the old mans garage. kinda father son toy on the weekends. Not too sure about these benz systems but didnt you say some thing about you were able to tart it from under the hood. lol when the notch had a bad solinoid you could start it by jumping the two posts with a screwdriver. Whatchya got dont to the 67? Your list gets mine.

OZCLK430

First Mustang - 68 Coupe, 289, Toploader
Second Mustang 67 Fastback, 289, C4
Third - 67 Coupe under restoration


Now - this frikin CLK430 !!!!

Removed and cleaned the TCU - same fault.

Any other thoughts......anyone ????

Regards

Dave

HWYSTAR

88 notch=331CID/Forged internals,tubular k-member/coilovers with drag pack/bag on pass rear,world class t5,AFR-heads,fully bolt on motor. Subframes,4w disc/5 lug,175 shot NOS. Put her butt on a diet/street trim with half cell and me in it=2782 pounds. Will do mid 11s all day long then throw on the drag radials for the trip home from the track. So now I have my new to me CLK430 and have to learn a whole new animal. Hmmmm maybe I will pull the engine and trans and swap in a built 306/T56 combo. now that would be interesting indeed.

OZCLK430

thoughts anyone....... Bueller...Bueller..


dave

MarcusF

Enough juice to unlock the doors and light the dash isn't an indication that there is enough juice to engage the starter.

Assuming the battery is good, move the shifter to neutral and try it there. If it cranks, you know what the trouble is. If not, FIRMLY place your foot on the brake and see if it will crank in either reverse or drive. If either of those work, you know what the trouble is.

Hopefully it's something inexpensive.

HWYSTAR

Cant fix it,rig it or modify it. What about bypassing the relay all together with a "push button" start kinda like on the newer bmw's and viper. Would this be an option?

OZCLK430

Sorry Marcus.

New battery 13.8v
Battery is not the issue

New brake switch

New trans " pilot seal "

Conductor plate on order though I am going to replace it simply out of " run out of stuff to do "

no crank in any position

OZCLK430

I must be obsessed !!!
I spent 3 hours last night ( 2am - 5am) in the shed ( snuck down there while the wifey was asleep) to spend some quality time with the mistress - "Karla"

"Karla Benz", all us Aussies name our cars !!!

Anyway, the K40 relay block, which is under the hood, pulle it out and has a good look - no signs of obvious damage, overheating, moisture etc.

Checked the CAN B voltages - seem to match the rest and ignition on states closely, so no signs of shorts.

The full dash and centre console is now also out of the car - and no signs of a pinched wire etc.

So - EIS, TCU,TSM, ECU, K40 - Which one is MOST likely??

Q1. The OBDII reader I have will not connect if teh car is not running - is there a reader that does?

Q2. Is there an aftermarket CAN B reader -at a realistic price ??

Q3. Does ANYONE update there posts when they find their problems?????


Frustration level - 9/10

HWYSTAR

I think at this point I would be throwing ***** around and swearing like a seasoned sailor. I have been there with some of my past rides before so I feel your pain. This may be something that you should consider putting it in the shop for at this point unless anyone else has an idea. At this point I would be calling the "doctor" to give my mistress "layla" a good once over for me.

HWYSTAR

Oh and BTW mine got her name from the Eric Clapton song. Its kinda ironic as when I got her the radio needed the security code before it would work so I had to go to the dealer for a new key and they took care of it for me. As I was leaving the dealer,after the many commercials that was the first song the play,hence her name.

OZCLK430

The local GURU (Mercedes trained), but working his own business now has been helping me. He is so flat out that he does not have the time to put the car in his shop - and of course its cheaper this way.

As much pain as it is, i am getting to know quite a lot about the merc systems and CAN B. While i admit that its a pain getting your head around, once you understand how the BOSCH standards work, it beocmes much less confusing.


Yesterday - subscribed to the www.alldatadiy.com website - $26 for a 1 year subscription, $16 for a second car. Very usefull.

Found a few measurements - and have started testing.

What I found.

1. Power to TCM ( Trans Control Module)
2. No signals to TCM - comes direct from conductor plate via the infamous pilot bush connector.
3. Just so happens that I replaced the old leaky connector about a month ago.
4. Removed Plug, removed connector (and the 7mm screw), looked inside to discover I have squashed a pin over.
5. Luckily, ordered a new conductor plate about 4 days ago.

SO - will fix this problem, and then restart the fault finding process.

( at this stage, I am thinking that I was lucky that it was the earth pin (33) that was bent - it it had been anyother, the symptoms would have been difficult to diagnose once the car was running as it would have manifested as a shifting error)

Regarsd
Dave

RCPDesigns

I don't know a lot about the MB system but I've seen many cases over the years where electronics functioned sporadically because of ground issues. As you probably well know given your electrical engineering background, the signal voltages are relative and if you had a bad ground then it might have worked for awhile and then quit. I'm hoping that this is the root cause of your starting problem.

OZCLK430

Hi All
Still going on this issue.

1. Replaced the Conductor plate - very easy job for anyone to do. Bit messy, but rather simple and certainly not a DIY that you would avoid.
The most difficult part is connecting the trans connector without bending any pins ( like I did last time and hence the reason for replacing the conductor plate).

2. Have printed out a forest full of circuit diagrams from alldatadiy -awesome website and once you get your head around how the Bosch wiring diagrams work - pretty simple to follow.

3. Have traced the "fault" to the ECU, output to the starter relay. The ECU should be giving me a 0V op and its staying around 4-5V and hence the starter relay remains open.

4. The trans shifter is possibly still an issue as the dash display is still a solid white block, ie no P/R/N/D info.

The alldatadiy gives a heap of test voltages to check and all seem to be well within spec.


SO - anyone got a trans shifter that they know is ok that they are willing to lend / sell/ etc ??

Regards
Dave

OZCLK430

ok - biting the bullet and going to purchase a new shifter mechanism....

Will let you all know how it goes

Regards
Dave

Jerry Sommer

If the dash display isn't showing N or P the ECU will think it is in gear. The microprocessor in the shifter sends the signal to the instrument panel. Jerry in Ohio

Droptop Benzo

das_ist_gut

Think I will name mine Brutus, but not until I find a bigger m113, until then will just call it Kaitlin (nee bruce).

das_ist_gut

Did your car turn over? My starter just clunks once and then nothing. Swapped out the relay for a different one and got multiple clunks with that....Still no start.
Mark.