Guddu05

Hi All

I have a Mercedes c220 cdi w203 sports coupe evolution

It has been displaying Coolant Visit Workshop.

I have checked the sensors coolant and washer bottle sensor, they are fine but I think my fan wiring is fault.. I have the following Wires :

1. Thick Red (Positive v12+) working fine
2. Thick Brown (Ground), some models can be black
3. black/white stripe (ignition from what i have researched) No power
4. green/blue (remote) this has 3.5 v when ignition switched on..

Usully the ignition should have 3.5 volts, why does my remote wire have this volt??? or on my model the remote wire is ignition???

I am baffled, any merc experts that can help?? My fan is not turning on at all, the car is not over heating, thermostat is working as well.

Also how does the AC work as on my controls I dont have an ac button i have ec and auto etc but nothing that says ac.. but looking at the engine i have the ac system including the pump and pipes..

I have one big radiator fan. Help me out guys I need to solve this problem so I can drive the carr

drm

Would you able to share the solution to your particular issue?
I hope it was a simple fix.

parasite69

I've got a c32 with the same probs. new cooling fan, new front Sam, ECU checked ok, new temp sensor and new ac sensor and still the fan doesn't work. Merc suggested a chafed wire in the engine bay. Still havnt found the problem. If you have a solution please share.
Cheers

C230 Mulac

I just want to share my experience in case someone looks for this in the future. I had coolant visit workshop a few weeks ago and was worried it was the fan. Car temp would rise slightly to maybe 100C then drop back to normal op at 90C each time the warning would come one.

I researched on here for a long time to figure out the problem and found a lot of cases where people replaced the fan but the fan wasn't the problem. I replaced my thermostat and coolant temp sensor since they were cheap parts anyways but the message was still there.

I was planning on replacing my water pump and rad hoses this winter as PM anyway since the car just clicked over 100k recently, so I went ahead and bought that and replaced it, and problem was solved. Turns out the car somehow knew that the water pump was starting to fail, not sure how as there are no electrical sensors in the water pump itself, maybe pressure sensor somewhere picks up on it. But anyways, $85 for a new water pump is much better than $600 for a new fan. So anyone who has pretty high mileage and hasn't replaced their water pump yet, maybe look into that before the fan. And while you're at it, it's not a bad idea to just replace the radiator hoses too so you know everything is nice and new with the cooling system.

drm

It turned out that the problem I had was a simple damaged wire in the harness. When we initially scanned ECU, we were unable to perform a test or activate the fan. Sometimes these's wiring issues take a great deal of time to find but it beats replacing unnecessary parts.

verlin samonte

would u know which area the damage was found , maybe same area a with my problem

drm

I believe they tested the wire connection from the fan to the fuse panel and found no connection or continuity. The damaged wire on my car was in the wiring harness just outside the engine fuse panel. Testing the connection/continuity should identify any break in the wires. I hope that helps.