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Hi people is there any auto electricians on here in the surrounding areas of Leeds UK? Or anyone with a good knowledge on electric faults on mercedes. I have fault codes and a scanner. I am a newbie to mercedes. I have tried all sorts with the help of good fellow people on this forum but no luck. The car won't start so i can't even take it to anyone. Thanks in advance.
Hi people is there any auto electricians on here in the surrounding areas of Leeds UK? Or anyone with a good knowledge on electric faults on mercedes. I have fault codes and a scanner. I am a newbie to mercedes. I have tried all sorts with the help of good fellow people on this forum but no luck. The car won't start so i can't even take it to anyone. Thanks in advance.
Can you give us the background details that lead you to NoGo?
Is this ....
"crank/no start" or "No crank/no start"
Can you give us the background details that lead you to NoGo?
Is this ....
"crank/no start" or "No crank/no start"
What is your scanner telling you???
Hi i have a no crank no start. With my scanner i found can bus c and canbus b connector which had water damage I bought connectors off a different mercedes with the same part number but the wires were other way round so i wired it the opposite way to make it right if that makes sense. Please correct me if i have done something wrong. This is is what my scanner is showing...
You have gathered a lot of info already. The security modules are unable to allow crank request.
No crank!
Water damaged modules have limited survivability rate. You will need to
1 - Locate all bad modules then
2 - replace modules and
3 - program replacement.
Actually I forgot the 1st repair step:
FIX THE WATER ENTRY POINT ASAP.
No new/old module will tolerate soaking.
15/5
15/3
"mute" modules are missing....
More modules will wake-up when bad ones are removedvfrom the bus.
Last edited by CaliBenzDriver; 07-10-2024 at 05:03 PM.
You have gathered a lot of info already. The security modules are unable to allow crank request.
No crank!
Water damaged modules have limited survivability rate. You will need to
1 - Locate all bad modules then
2 - replace modules and
3 - program replacement.
Actually I forgot the 1st repair step:
FIX THE WATER ENTRY POINT ASAP.
No new/old module will tolerate soaking.
15/5
15/3
"mute" modules are missing....
More modules will wake-up when bad ones are removedvfrom the bus.
Are these the modules..
If they are then i have re wired can c and can b wires already. The only difference was the wiring was the other way round but the part number was exactly the same. How do i program this please?
Are these the modules..
If they are then i have re wired can c and can b wires already. The only difference was the wiring was the other way round but the part number was exactly the same. How do i program this please?
this is not a module.... this is only a "bus distribution bar" used to inter-connect many modules on a particular CAN- B or C bus.
Each of these CAN cables is connected to a module at the other end.
Last edited by CaliBenzDriver; 07-10-2024 at 06:58 PM.
Great detective job with your scanner! "smoking gun" located
Now we know WHY you're getting "No Crank" condition.
> Status:
Two of the main security modules (EIS + ESM) are disabling crank. These are the gear shifter plus the ignition key module upset by swampy bus bar.
> What To Do....
-- Concentrate on fixing the bus distribution bars we know got swamped. When that's satisfactory these two module will should come back clear and ready to enable start.
-- These modules are NOTdefective, only CAN Bus itself is defective. You're savings stacks of cash by not replacing good parts in a hurry.
-- This is not a guarantee another module (F-SAM) is not bad. We'll cross that bridge when we get there, using your scanner.
-- We are going to eliminate the source of "No crank" then see what other faults remain.
++++ CAN Bus signals have polarity...
-- When you reworked your bus distribution bar hopefully you did respect CAN-HI/LO as being distinct signals.
-- Wiring just needs to stay identical regardless of colors being different with replacement cables.
Last edited by CaliBenzDriver; 07-11-2024 at 03:43 PM.
Great detective job with your scanner!
Now we know WHY you're getting "No Crank" condition.
"smoking gun" evidence
> Status:
Two of the main security modules (EIS + ESM) are disabling crank. These are the gear shifter plus the ignition key module upset by swampy bus bar.
> What To Do....
-- Concentrate on fixing the bus distribution bars we know got swamped. When that's satisfactory these two module will should come back clear and ready to enable start.
-- These modules are NOTdefective, only CAN Bus itself is defective. You're savings stacks of cash by not replacing good parts in a hurry.
-- This is not a guarantee another module (F-SAM) is not bad. We'll cross that bridge when we get there, using your scanner.
-- We are going to eliminate the source of "No crank" then see what other faults remain.
++++ CAN Bus signals have polarity...
-- When you reworked your bus distribution bar hopefully you did respect CAN-HI/LO as being distinct signals.
-- Wiring just needs to stay identical regardless of colors being different with replacement cables.
Thank you for this information! ^^^
I will rewire CAN C green to green and green/white to green/white and the same with brown/ red on CAN B. The blocks i bought had the exact same part numbers just the colours of the wiring were other way round so i assumed to make it identical to the old block i have to wire it the opposite 😳
I will rewire CAN C green to green and green/white to green/white and the same with brown/ red on CAN B. The blocks i bought had the exact same part numbers just the colours of the wiring were other way round so i assumed to make it identical to the old block i have to wire it the opposite 😳
I will report back very soon 🧐
Yes, I think you got it:
> The chassis only care that each CAN Bus Hi+Lo signals still land in the same spot as it did originally.
Meaning CAN-HI/LO must not to be mixed up.
> The position where each connector lands on the bar is not critical but should be preserved because slots are assigned to individual modules.
Meaning connectors should not be mixed up.
> While the chassis is undergoing bus surgery, disconnect all batteries and charge them.
This break will provide a fresh reboot to help sanitize goody modules....
Last edited by CaliBenzDriver; 07-11-2024 at 04:53 PM.
07-10-2024, 01:57 PM
