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Hi all


New to the forum (and Mercedes) with a 2002 Clk230 convertible automatic

The reversing lights and rear parktronic have stopped working. Not a fuse or bulbs, googling suggests a switch in the gear shifter unit, on disassembly only find part no A0025421018 which is tiptronic selector module- does this operate reverse lights or is there a separate external switch.
Any help/suggestions would be much appreciated

Thanks
 

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Hi all


New to the forum (and Mercedes) with a 2002 Clk230 convertible automatic

The reversing lights and rear parktronic have stopped working. Not a fuse or bulbs, googling suggests a switch in the gear shifter unit, on disassembly only find part no A0025421018 which is tiptronic selector module- does this operate reverse lights or is there a separate external switch.
Any help/suggestions would be much appreciated

Thanks
Will let you know how I get on. Have the same issue but my Star cant find the problem. Check in the dark if the led lights follow were the gear lever is. Mine do when its working. The wires that go through the gear selector are just in and out with the lever making the circuit. It must be a can issue as when you leave it for an hour it comes back online. Also when you turn the lights on I get blown bulb warning. This always means to me the the reversing lights have lost there earth/power somewhere. Get out and check and there not working with the car in reverse gear not running. It only happens when you put the lights on. Hmm power surge draw through the earth circuit then the CAN BUS chirps up and issue. But were? My car is in bits with the rear bulkhead out as its a soft top and there tonnes of earths everywhere you look. Hack into the boot hinge wiring boot rubber and there 6 earths in there.

I am sure its a bad earth somewhere. I also loose mirror adjustment and power to rear windows from the switches.
Windows work fine on remote key so its sure not the the motors. I have all the carpets up,centre consul out,lower dash on both sides. Two second hand SAMs as I was sure it was them at first.

Replaced my whole gear lever selector...no joy. fuse boxs...no joy...every relay....lower N72 switch module..no joy..EGS gear module no joy. Checked the main brown earth to the selector and there is Zero ohms resistance to the body.

No sure whats going on apart from the blue wire to the switch has been getting hot and the outer plastic is warped. But who drives anywhere that long in reverse for it to start cooking the wire but not blowing anything.

Seems the whole system including the Parking sensors and rear seat led run on the same loop. car drives perfect one minute the a dog the next. Star says cant communicate with EWM Gear selector. Well how can the gear box then? as 1st 2nd and 3rd are all electronic and work very well. Star can tell you were the gear lever is reading through the EGS module but cant find the gear selector.....that's bonkers.
 

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Are you sure that you have checked the right fuse?

The exterior lights are in N7/1 (Light module) located behind a cover at the end of dash dash panel, drivers side.) Open the door to remove the cover. Fuse f4 (15A) protects: reverse lamp, turn signal lamp, Parktronic system.

The initiating reverse lamp switch (S16/2) is located somewhere on the transmission assembly (I think) but I cannot find the picture in my WIS.*

later - I think that S16/2 is only used on the manual gearbox. So possibly the signal comes from the ESM. (selector module N15/5)
 

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Thanks for your reply but I have found the issue. My Star could never have found it as it was inconsistent, but enough to stop the lights working and throwing a dash bulb fault when it felt like it.Then fix itself !!

I Will post in detail how to fix the reversing lights with photo graphic evidence.
Its a 50p safe fix.
Any car earlier then 2012 and a customers car it would be a write off, and should of been a factory recall as the supply wire overheats to point of melding soldier.
 

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I am the forum moderator and I don't see any blocked or auto-moderated posts. Sometimes when a forum member with too few posts tries to included photos or external links, they get auto-moderate, but I can see those and approve them as needed. Another issue is that if you are trying to include a photo from an external site, it must be secure (https). Otherwise, the forum just ignores the link. Let me know what message(s) you receive when trying to post and we'll try to get this on the forum.
 

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Evening Gents Reversing lights Solved
Ok so your car keeps saying on the dash Bulb failure, and when you check you there’s no reversing lights. Then for no reason they will come back on when you leave the car an hour or so.
Hundreds of post are telling you check brake light switch?,earths to body?,battery dying?. Poor Earth from battery to chassis even though the car starts fine as its drawing about 500amps to start a V6 320cc.
As this bulb failure normally occurs when you are in fact bring lots of systems online it’s hard to point to the problem.
1)So you put the key in and its instinct to put your foot on the brake. That’s two systems brake light circuit and Electronic key recognition.
2) You then put in reverse with your foot on the brake. That’s the reverse circuit, brake light circuit, parking sensors on the bumper plus the led display between the rear head rests and don’t forget the mirrors as they tilt. That’s five systems all online at the same time. Running off what Fuse? That repairs itself?
3) Night time its all the above plus headlamps draw and rear lights. Logic says it must a bad earth as all these happen at the same time and send the dash fault.
4)That’s 6 systems all going I’m here! feed me. With dash saying it’s a blown bulb.
But you’ve checked them 5 times at least cleaned all the contact areas and plugs.
Even spotting a bulb from Halfords that was 12v 23watt instead of 21watt. I didn’t even know they made them but they do and can easy send you system into a Brain Fart as the resistance in Ohms’ is not the same.
So you have cleaned the earth’s as pointed out using the Star as every W point is brown for earth. No joy. Car being an old CLK320 that’s not coded as it’s an S reg 1999? Means every part will be accepted with the same part number. Change Sam, Fuse boards, gear selector module,3 brake light switches, and all you get is “CAN this CAN that” then fixes itself. Then windows don’t go down on the rears and boot release stops working. N72 module. Oh yes replaced that as well.
STARS says no issues even running in-depth diagnostics. No codes? Many wiring Diagrams latter saying f1- f4-f24 all wrong.
So back to Basics: What’s the car. Front half is E-Class but all the rear brakes and ABS sensors are off a W202 C- Class. Check on Star and that reads the Chassis number and points you in the direction of wiring diagram that looks nothing like my car, as all the colours after being translated from German are all different.
Read deeper and every module says its ID software number is dated 1997 so you have wasted weeks looking at garbage wiring Diagrams for a car made two years latter.
From the A- pillars back the car is W202 Class with the roof sawn off.
Find the wiring Diagram for a C -Class and the wires that go to the reversing light switch match. Follow the main feed to the reversing light switch and it leads to FUSE F1. What a load of rubbish.
Test I don’t recommend unless you have the ability to clear every code possible.
Open boot-trip boot lock with screw driver so it thinks boot is shut. On the boot lid on the left on the catch is white plunger that sets the boot light on/off. Pull it out till it clicks and the light goes out “service mode”!. So now the car thinks the boots shut when it’s not and you can see the reversing lights with boot lid open from the fuse board at the front.
Put handbrake on hard! Put into reverse with key on position 2 (run setting). So now you have made a circuit. Diagram says Fuse 1…..pull it out and reversing lights stay on. Pull every fuse out one by one to see when then bulbs go out. And not a single fuse puts those lights out. Open up the ECU box on the nearside. (left). There’s about 6 fuses and still these lights are on.
Ok let’s check the boot’s 9 fuses and still nothing. By now you have told the car everything its going into melt down and will have set may faults codes. What’s left?
End of dashboard on drivers side is a panel that pops off with screw driver this does side lights and such. You cant see them properly but can pull them out. And BINGO fuse 12 lights go out. Which is lower column right hand side. Give it a wiggle and the reversing lights go on and off.
Now this is important: Top row of the fuse’s is the live feed. The bottom row of the same fuse feeds the accessory.
So by now you have all the centre consul tangling on wires trying to see this reversing light switch. Trouble is there a cross beam in the way of the wires. Well it’s made of plastic so use a hack saw blade wrapped in rag and cut it out.
Now you can see it BLACK AND BLUE supply line all crinkled from heat and GREY GREEN two feeding out to two 21w bulbs + from the two pin Heavey duty reversing light plug in the gear selector.
Using a scalpel as in my pictures cut back the outer protection so you can probe it, don’t go shoving a pointed tester in there as it will cut the wires. IF YOU HAVE A CONTINUITY TESTER ITS TIME TO GET OUT AND CHECK THE REVERSE SWITCH FOR TRUE 100% CONTACT IN (R)
My SW/BL (BLACK&BLUE) supply line was at that time feeding it. Probed it 12.6v with ignition on in Park. Started car in Park and probed again and it’s still live putting out an unregulated 14.2 volts on a single 0.5mm cable that’s running the whole show and having a meltdown. It’s like rewiring your kettle using speaker wire you just know its going to burst into flames. Mercedes Recall……No chance!
So now key pos 2- reverse- put headlamps on and foot on brake and all the power to that reversing light switch just disappears. Nothing!! Cant be CAN BUS crap as its direct live.
Go and have a cup of tea-watch the news-have your dinner and try again and all the power is back to that line. It’s not and earth issue. It a power supply issue of an over heated wire that runs near the heater box then up to the fuse board which is the light control switch Module.
Now this light switch of course is not just simple switch. It has Microchips, printed circuit boards and a fuse box micro soldiered to the printed circuit board by a robot. Its a no go repair!!
Main power to fuse 12 is good and strong and the other side is like a wobble tooth. Out the back of this light switch unit is the Black and blue that feeds the reverse that’s over heating through amps.
So now the car needs the Dashboard out and a new wiring loom and new light switch. Can it get any worse?
Replacing just the switch for second hand one will only half do the job, as there’s still the pathetic wire feed to the rear lights. New Patent part Light switch Ebay £300.00 and what does a loom cost?. 15-20 hours labour taking the whole dash, steering wheel, carpets ,under bonnet fuse boxes, Then resetting the whole car up again using Star. ££££££££££
OPTION TWO.
Get a 15amp Fuse. Drill a 1mm hole through the exposed metal section. Get a metres worth of cable and peel it back 25mm. Push cable half way through fuse hole and place fuse in the holder with the cable at the bottom. Now you have still have the blue and black connected but the new lead will ease the amp load. Run cable under dash over the top of the heater vent and round to the gear lever.
With a Scalpel peel back a 8-10mm section of the blue and black outer shield and soldier new fused wire in-place. Scotch locks are too risky as it might cut your original. You also cant shrink wrap it as you haven't cut the wire so use self amalgamating tape from Halfords.
Job done. Cost 50pence and NO MORE PROBLEMS.
I have Pictures to upload and might even try a Youtube clip that shows the light fuse breaking continuity on f12.
 

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I have Pictures to upload and might even try a Youtube clip that shows the light fuse breaking continuity on f12.
I suggested that you look at fuse f4 in post #3 (but only for LHD model) W208. It is fuse f12 for RHD models. But your profile does not include COUNTRY! Who knows where Waltham Chase is?

I might have missed your point above - but if you suspected that 15A fuse f12 was not man enough for the job, why not try a 20A fuse and save a lot of time?
 

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Yes I believe you have missed the point.
The fuse contact to the printed circuit board is failing. The Amps drawn through the 15 amp fuse to the black and blue reversing light cable is already enough to make the cable overheat and making it buckle and warp and not blow the fuse.
The reversing lamp contacts inside the lever are 2mm. "live in and live out". Cable size is too small on the supply side as the output has two leads soldiered to the pins.

Adding a 20amp fuse to a circuit that is already getting to hot will not help as it will catch light or fry the printed circuit board.
 

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OK. Maybe I now understand something what you are telling us. But although you have posted here on the W208 forum I have no idea what MB model car you are referring to.

However, I do find your argument that this is a design fault on a car no longer in production, that has not been discovered before, is a stretch of the imagination. I have been using this forum since 2006 and I have not come across this precise fault before.

In general, we have seen that cars with excessive currents causing faults have had additional features added by one of the numerous previous owners. Just removing the feature does not always put the circuit back to where it used to be.

In your case, there are a number of different consumers using that fuse. Why not remove them one at a time to discover which one is drawing the high current and damaging the wiring. The reversing lights cannot use 15A surely?
 

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In your case, there are a number of different consumers using that fuse. Why not remove them one at a time to discover which one is drawing the high current and damaging the wiring. The reversing lights cannot use 15A surely?
+1

Can't see the reversing lights drawing so much current, and unless you drive everywhere in reverse, they would only draw that for a few seconds each time.
 

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I Agree most reversing is under 30 seconds. A 15 amp fuse is what used on a cigarette lighter. These have big junky wires as they can pull 180 watts from a 15 amp fuse.
These reversing lights are only 2 x 21w which equals 3.5 amps. LED parking sensor maybe 0.5amps that's four amps in total.

This means the the Parking sensor ECU under the false bulkhead beside the gearbox ECU in the passenger foot well must be pulling 10 amps from the reversing light switch.

They also power four parking sensors but they cant surely cant pull more then 1 amp for safety reasons and the audible alert.

If it pulled 11amps the fuse would "slow blow" over a matter of weeks.
That's why the cable cant cope as its a third the size it needs be. It the same size as the micro wires that come from the gear selector or speaker tweeter leads.
 
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