eye of ra

Since buying my CLK430 I have learnt that the previous owner may have told a few, shall we say untruths, about the cars history and condition, it certainty should have not passed its MOT it had the day a bought it.

Anyway I am a little confused about my latest finding. Having had a few problems I purchased some OBD-II software and a connector, it picked up a couple of codes that I sorted. My issue is that the software said the CEL was ON but it wasn’t.

I have now deliberately made other fault codes appear that should make the CEL come on and it doesn’t (it lights up and goes out at start-up/test so bulb is ok).

How does this happen and more impotently how do I make my CEL work as it should again? I don’t want to have to keep plugging in my laptop just to see if my engine is OK.

Plutoe

The CEL is just an indicator alerting the driver that there is an issue with an emissions related system\s on the car---the ECU senses the abnormal data and through time and frequency of the abnormal data will then create a fault and advise you via the CEL.

If I were you I would get the car scanned by the dealer or indy with MB diagnostic software DAS Xentry-----then and only then will you find the real story!!

eye of ra

Thank you for your reply.

Does this mean the light is connected directly to the ECU for both start-up test and fault display?

I may just be being cynical (due to other issues I have had) and this is due to a genuine fault with something (ECU?) and not deliberate.

This is what I have none. Cleared fault codes so laptop showed NO FAULTS, NO PENDING and CEL OFF I then disconnected the MAP, drove the car and read the codes it then had 2 PENDING and CEL OFF drove the car again and pending became 2 FAULTS and CEL ON. I reconnected MAP and cleared codes then disconnected the MAF, again 2 PENDING (obviously different) codes and CEL OFF after first drive and after another drive 2 FAULTS and CEL ON but at no point except at start-up did the CEL on the dash actually light.

Is there somewhere I can test with a multi-meter?

I would rather not take to any garage for this at the moment as there are other things that need money spending on first and in this respect car is usable.

Plutoe

What software are you using!!

eye of ra

Did all described with EasyObdII but also used ProScan 5.9 once to check when the MAP FAULTS and CEL ON were showing and it confirmed EasyObdII’s results.

eye of ra

Well looks like its deliberate.

Was thinking last night while I couldn’t sleep, “how does it do an engine test without the engine running? “

Answer IT CAN’T.

So I looked in the manual this morning at how it’s supposed to work. Come on at position 2 and go out after engine starts.

Well mine comes on at position 1 and goes out after 4 seconds whether engine has started or not. Remind anyone of another light? SRS maybe.

Without taking dash apart I recon someone has paralleled the CEL with the SRS light which is enough to make your average buyer (me) think everything is ok.

So as long as there is not supposed to be a warning in the multi-function display as well when CEL lights it shouldn’t be too difficult to return car to normal when I take dash out to repair temp and clock displays.

jptaylor

Ive seen this many times, people will pull the cluster and either pull the CEL bulb, Repin the CEL bulb socket to the SRS terminal or find another way to disable the CEL..... Not that hard to do and dishonest as hell. Good catch with watching the ignition warning light sequence at accessory/startup

burgca

SRS and Seat Belt go out before start
Link to bulb size
https://mbworld.org/forums/clk-class...ter-bulbs.html

here is a YouTube video on replacing the ribbon

Good Luck!!

eye of ra

Thought I’d post an update.


Thanks for link, clock and temp gauges are now all working, along with all illumination bulbs.


Guess what I found on removal...... two cut tracks and some wires connecting SRS and CEL, also now repaired and all working as it should.

burgca

Congrats

calda

Thanks for the info. provided.

donyou know any features that can be unlocked in these cars?
any info. or video links provided would be appreciated.

i was able to find lots of YouTube Videos that illustrated coding the C5 but very reluctant in finding any coding instructions or videos on what can be unlocked on the MBs.

mor specifically I’m 👀 by to see if I can unlock the following:
1. dVD
2. Clos By the trunk with the key fob
3. Winding up/down/closing the roof with the key fob

Many tips and tricks would be greatly appreciated.

regards,