nikifive

Hi All - I am looking for a good advice on my car repairs. I am very happy to be part of this forum as there is good knowledge around.

This is what happened to me recently:
End of January - I used to hear a chirping noise from near the dashboard.
End of February - One fine morning - I start the engine and then the sudden turbine engine noise without starting the engine. The coolant/radiator fan is always on high speed.
Mid-March - I changed fan, coolant temperature sensor, checked fuse box (front SAM), coolant flush...but to no luck. Based on my mechanic's recommendation he checked the wires from ECU to Fuse box and mentioned to repair the ECU or get one from dealer for $2,400. I got my ECU repaired instead. Still the Problem exists!!!!!!!!!!!!!!!.
The only surprising thing is that the chirping noise is gone.
Two days back: All of a sudden I get a check engine light on.

I am really frustrated and have a dealer appointment this Friday. I don't know where else can I go to trust a mechanic specializing in MB. I am located in central jersey. CAN SOMEONE PLEASE HELP ME FOR ADVICE ASAP

phister

go to a parts store and have the code read.

also have you tried getting the fan switch checked? or checked the relays

nikifive

Yes - the local mechanic checked the fan switch, relays and fuse box. They said there is a continuous signal coming in to the fuse box which is sending the signal to the fan. Initially they said the ECU is bad, and I got it repaired but did not fix. Now they saying it could be the climate control unit or the instrument cluster. Can the problem go this deep? Any ideas?

SunnyRayToronto

How was the ECU fixed?

Your mechanic is either a con-artist or an idiot,... an idiot just pissing in the dark,... just pissing away your money!

SEARCH,... for ECU thread started by me

Get a real Mercedes Indy,.... one way to test if it's really ECU at fault,... plug in another ECU - of course it won't start the car - but it shouldn't fire off the front radiator fan in high mode,...

nikifive

I read your forums and details. My ECU was re-programmed/re-manufactured by mercedesecm.com (ECU Technologies). Let's hope that ECU is working. For plugging in another ECU; does it have to be a c230 or any car/model? I am planning to get it to the Mercedes dealer to get to STAR/Xentry and get a detailed report.

For the error code: I got a OBD2 code reader scanned by Advance Auto Parts. It show a code P2190 System too rich at idle bank2. What dose this mean and can I fix it myself???

nikifive

Planning to get the fan problem checked to the dealer..is that a good idea just to understand the root cause and then go to a private Mercedes specialist to fix the issue?

SunnyRayToronto

Ecu needs to be for same engine type

Front radiator fan is working properly as it should,.... If it does not get signal from ecu it will spin in high mode like a turbine engine,.... It assumes worst case that engine is overheating

nikifive

Today - I went to see the dealer. They asked me who did the fan job as the fan may not be working correctly. They said they needed 3-4 hours just to install the fan and take it from there. I told them I have a spare fan to do your testing and the new fan was bought from their parts department. Then they tested it free of charge; came back to me and said fan assembly/module is good and so is the wiring connected to it.

However, they discovered that my ECU was repaired by a third-party so they did not want to look at it and said its the ECU and you will need to replace the ECU for $2,700. They also mentioned that the ECU is continuously sending the signal to the fan. This is what the other mechanic told me too; and after I spoke to the ECU guy he said your part is under 3 year warranty and we can send you a new one once we have your old back. Even he mentioned that it is highly unlikely for your ECU to go bad....this is what I feel too - I was looking at a forum: https://mbworld.org/forums/c-class-w...t-normal.html: It talks about some version coding with regards to KI Instrument cluster, Ignition Switch Module (EAS/EIS); AAC/TAU (Automatic Air Conditioning); Automatic temperature control. that could be causing this issue? Has anyone ran in to this.

Another forum talked about the climate control head unit going bad as the A/C unit (besides the ECU) can send signal to the fan....

ANY ADVICE on this please?????

SunnyRayToronto

Like I asked earlier,... what was fixed at the ECU?

Has your ECU ever been tuned?

Yes, its very rare that ECU becomes defective,... but it does happen,... don't ask me how I know!

Do yourself a favour,... when you take the ECU out,... shake it and see if it rattle,... it's NOT suppose to rattle!

How did the Dealer know that your ECU was repaired? Was the seal broken and resealed?

My new replacement ECU for 2003 C230 with M271 engine costed about $800 from my local Mercedes-Benz dealership (including discount) and another $500 for my Mercedes Indy to diagnose and SCN code.

What you're calling Version coding is SCN (Software Calibration Number) coding.


Your post really doesn't make a lot of sense,.... if you're saying you sent out your ECU to be repaired,... and when you got it back it still produced the exact same problems as before,... If so, then the guy who repaired your ECU really didn't repair it at all. Or if he did repair it, then the fault wasn't in the ECU but something else,... thus someone should really check your wiring,.. especially signals along your CAN-BUS. BTW,... the repair that those ECU specialty places usually do is they just exchange your ECU with another used ECU,... and switch out the chip from your original ECU that holds your car Serial number (VIN code) & SCN number so that the replacement ECU will work on your car. If this is the repair that was done, its highly unlikely that both original ECU and used replacement ECU suffers from the exact same defect!

Did your Mercedes Dealer or Indy examine the car using their STAR diagnostic system? Did they examine the CAN-BUS? Did they switch out the ECU for another ECU to see if they fan still goes nuts?

nikifive

The dealer got to know about the re-manufactured ECU since there is a label at the bottom of the ECU that it is re-manufactured by the third-party replacing the original one with the date. The dealer report says that they performed a SDS (STAR) short test and found code 0695 for the engine fan. The code 0695 stands for Fan 3 Control Circuit Low !!! Any IDEAS/THOUGHTS here??????????

I will ask the ECU guys to provide me with a new one as the fan issue is still on. They agreed since it is under 3 year warranty.

What I am planning to do next is like you recommended is to check the wiring and signals along the CAN-BUS. I will also talk to them about the Code 0695 as well. I suspect it could be the wiring as a few days before this problem I was hearing a chirping noise around my dashboard and the problem is gone now. I will to go to a Mercedes specialist to talk about the SCN and check if the A/C system is not sending in continuous signal to the fan and whether there is short circuit in any wiring due to the chirping noise before.

What are your thoughts???....I like this car and do not want to sell it.

serrano8349

I NEED HELP I HAVE A MERCEDES E 500 2005.. AND I AM HAVING THE SAME PROBLEM MY COOLANT FANS STAYS ON HIGH MODE... SOUNDS LIKE A TUBINE ENGINE...ALSO SAYS VISIT WORK SHOP... I CAN START THE CAR AND DRIVE BUT DON'T WANT TO DAMAGE ANYTHING ...
WHAT CAN BE THE POSSIBLE PROBLEMS ANY IDEAS.....

nikifive

Hi Serrano - With all lost hope and no dollars to spend on research, I am simply driving the car with the fan staying on high speed. My commute to/fro work is 40-45 minutes and have not had a single mechanical issue. The only thing I have noticed is that my coolant visit workshop sign will come on after 1 mile drive and intermittently come/go every 30-40 seconds and then my engine temperature indicator would increase by 2 degree from 80-85 to 87-90 and go off.

Like Sunny recommended above: it can be the electrical wiring through the CAN-BUS if the radiator fan and ECU is working fine. I even changed my thermostat/coolant temperature sensor/coolant flush and still the same issue. Two individual mechanics + MB dealership is gearing towards electrical problem since the fan relay is continuously getting a signal either from the ECU or the dashboard is sending it to the ECU or to the relay (not sure). In my case, I am starting to suspect it is my dashboard as even my time changes back 1 hour after I change it to EST and the whole temperature indicator fluctuations with coolant visit workshop warning.

Hope this helps.

HeatherDavis

Spiratically my engine fan comes on say coolant workshop. Car does not run hot. Drive does not change. Have been told a number of things first time owner not really sure where to start, but don't want to pay unnecessary money to "research" the problem. Please give me some advice!!!!

nikifive

I am in the same position as you are. My car does not run hot and drive feel does not change, and told a number of things as well. I am still driving with the same problem of sporadic coolant visit workshop, engine light comes on then off but with no drive problems for 2 months now. The only thing that is concerning me is the Inspection which is coming up in a few months. Does any one know if inspection will pick this problem and fail me???? If anyone has resolved this issue, please let me know as well. I am desperately looking for a solution too.

mtnman82

In CA you will not pass if any check engine light is on. Have you guys checked the coolant level? It should be up to the black (top) part of the reservoir. Some of these cars also have the wiper fluid tied in to the coolant warning circuit, so it could be you're low on wiper fluid too. Those are the easy fixes. It is also not uncommon for the sensors themselves to go bad. It's not terribly bad to replace either (coolant tank is pretty easy).

phister

In texas I think they just check your emission sensors like the EGT, O2, and a few others when they do the inspection, plus the usual like blinkers and so forth.

HeatherDavis

I just had my coolant sensor checked nothing wrong there, fluids are good. I'm so frustrated. I have been even told to replace the fan.....but what if its not the fan? Money wasted.....crazy. Every post I have seen with the same problem has done different things but no real resolution. One guy said he redirected the wiring. It's very discouraging because u feel you are buying a good car....maybe not.

HeatherDavis

My whole problem with this is I'm hearing dealers are supposedly working on these cars and "guessing" too. If you take our car to the dealer. You shouldn't have to return it. Not like this. Period.

nancy1968zx

How was the ECU fixed?

nikifive

OK PPL - I have my coolant fan problem FIXED finally... The problem was a bad wire (short wire). My local trusted mechanic for years finally opened the wires and located the culprit. There is a voltage wire that runs directly from the ECU to the fan switch. The pin number is 43 on the big plug (the other being a small plug) that fits the ECU.

What we did is we ran a "bypass" by:
1. borrowing a spare wire from another car (nissan)
2. bypass the wire from pin 43 directly to the fan switch and determination worked

So the coolant problems can be due to a number of reasons but if the issue is similar to mine as explained in this post then please check the wiring, ask them to check the wire/ground. Note that these cars have a lot going electronically so the fan module can also go bad and so can the ECU..in my case it was the fan control module (that comes with the fan), ECU and the wire. Before fixing an ECU, you can also give it for diagnostic test ($50-100) before making any replacement or repairing. My ECU was bad because it was a little burnt due to the wiring issue. So I got it replaced with another one where they transfer the data from your old ECU to the new ECU and reprogram your keys to work with the new ECU

The car runs in good condition as before for 2 days now with no over heating and already drove 150 miles and no problems found. I hope Mercedes has recall on the fan issues and hope this problem gets fixed soon for others