Coolant light on, Need Help!!!!!! - Mercedes-Benz Forum
 
LinkBack Thread Tools Display Modes
#1 (permalink) Old 06-13-2006, 05:42 PM
BenzWorld Junior Member
 
Date registered: May 2006
Posts: 5
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
(Thread Starter)
Coolant light on, Need Help!!!!!!

I am not one to have the vehicle tooken to the dealer for something small, but this seems to be a bit of a problem here. So I am asking for some help.

My moms friend has a 2000 model CL500 and yesterday morning she called my mom to ask her if I would come look at her call cause the coolant light was on. So I went over and her car has the message on the cluster that says "Coolant Visit Workshop". Well assuming the level is low, I check the resovoir and the level is at the top of the container. Well now I am assuming there is an issue with the coolant level sensor.

Well after talking with my friend at the mercedes dealer (he isnt that experienced with mercedes since he hasnt worked there very long and he did however tell me that the coolant level sensor is in series with the washer fluid level sensor. and if either is faulty it can trigger the other one. he also gave me some specs from netstar for the resistance on both switches. both have a resistance of less then 5 ohms with a low fluid reading and 110 for a full reading for the coolant sensor and 160 for the washer level sensor.

Well armed with that info I decided to first test the washer level switch/sensor. now I found that the sensor is magnet operated and with it closed (fluid full position) I had 0.0 ohms and open I had 170 ohms. immediately I assumed the switch was faulty since the readings were opposite. and since 0.0 ohms means something is wrong. friend said it is most likely shorted. Well I went a purchased a new switch from the dealer which had to order it since it wasnt in stock and we got it in today. Well I picked it up and after I installed in, the message was still displaying "coolant, visit workshop". well I pulled off that switch and measured it and I got the same readings, only this time I got 0.4 ohms with it closed and again 170 ohms with it open. now I have a feeling that the specs on netstar may be wrong. So I went and checked the reading of the coolant level sensor with the coolant in the resovoir and it read 110 ohms with the coolant full. which is in spec.

Now just to check to see if maybe this was a wiring issue, I disconnected the coolant sensor and looked at the cluster and it said this time, coolant level low. and also coolant, visit workshop. plugged it back in and the low level went away, but the other message stayed. I then unplugged the washer fluid level switch and the cluster said washer fluid level low and coolant vist workshop. plugged it in and only the coolant visit workshop remained.

So I am stumped at this point. it seems like the wiring is fine since the cluster reconizes that the switches are connected and what not. My friend said the info went through the front SAM and I assume from there is is sent on the interior can bus to the cluster.

Now is it possible that there is a CAN issue here? or possibly a faulty SAM or faulty Cluster or just maybe one or the other needs to be flashed? not sure how else to check this issue, if anyone has an idea, please let me know?

Also would this issue bring up any codes through SDS?
craft1 is offline  
Sponsored Links
Advertisement
 
#2 (permalink) Old 03-08-2008, 03:13 AM
BenzWorld Newbie
 
Date registered: Mar 2008
Posts: 2
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Coolant Level Sensor

Quote:
Originally Posted by craft1 View Post
I am not one to have the vehicle tooken to the dealer for something small, but this seems to be a bit of a problem here. So I am asking for some help.

My moms friend has a 2000 model CL500 and yesterday morning she called my mom to ask her if I would come look at her call cause the coolant light was on. So I went over and her car has the message on the cluster that says "Coolant Visit Workshop". Well assuming the level is low, I check the resovoir and the level is at the top of the container. Well now I am assuming there is an issue with the coolant level sensor.

Well after talking with my friend at the mercedes dealer (he isnt that experienced with mercedes since he hasnt worked there very long and he did however tell me that the coolant level sensor is in series with the washer fluid level sensor. and if either is faulty it can trigger the other one. he also gave me some specs from netstar for the resistance on both switches. both have a resistance of less then 5 ohms with a low fluid reading and 110 for a full reading for the coolant sensor and 160 for the washer level sensor.

Well armed with that info I decided to first test the washer level switch/sensor. now I found that the sensor is magnet operated and with it closed (fluid full position) I had 0.0 ohms and open I had 170 ohms. immediately I assumed the switch was faulty since the readings were opposite. and since 0.0 ohms means something is wrong. friend said it is most likely shorted. Well I went a purchased a new switch from the dealer which had to order it since it wasnt in stock and we got it in today. Well I picked it up and after I installed in, the message was still displaying "coolant, visit workshop". well I pulled off that switch and measured it and I got the same readings, only this time I got 0.4 ohms with it closed and again 170 ohms with it open. now I have a feeling that the specs on netstar may be wrong. So I went and checked the reading of the coolant level sensor with the coolant in the resovoir and it read 110 ohms with the coolant full. which is in spec.

Now just to check to see if maybe this was a wiring issue, I disconnected the coolant sensor and looked at the cluster and it said this time, coolant level low. and also coolant, visit workshop. plugged it back in and the low level went away, but the other message stayed. I then unplugged the washer fluid level switch and the cluster said washer fluid level low and coolant vist workshop. plugged it in and only the coolant visit workshop remained.

So I am stumped at this point. it seems like the wiring is fine since the cluster reconizes that the switches are connected and what not. My friend said the info went through the front SAM and I assume from there is is sent on the interior can bus to the cluster.

Now is it possible that there is a CAN issue here? or possibly a faulty SAM or faulty Cluster or just maybe one or the other needs to be flashed? not sure how else to check this issue, if anyone has an idea, please let me know?

Also would this issue bring up any codes through SDS?
This message is coming from your onboard computer which may be faulty. If you cannot live with it then the only course of action is to take it to the local dealer.
woktan is offline  
#3 (permalink) Old 05-06-2008, 09:17 AM
BenzWorld Newbie
 
Date registered: May 2008
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Just check your cooling fan, I've had one with this fault on it and it had nothing to do with the coolant level, but was the cooling fan motor. Just check if it moved freely. The one I had was siezed.
sparksRus is offline  
#4 (permalink) Old 05-07-2008, 06:49 AM
BenzWorld Member
 
Date registered: Dec 2003
Vehicle: 2002 CL 500
Location: west palm beach fl.
Posts: 222
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
best thing to do is unplug these unimportant sensors and just periodically make sure all fluids are full by manual inspection, why make yourself crazy by playing games with this electronic junk. the electronics and sensors work better in my forty year old airplane than these cars. but fortunatley my cL with 67,000 on it has had no problems yet. you could bring it to the MB shop and pay a fortune to have it analyzed and repaired, and it's probably something simple good luck.
reliablebruce is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > Mercedes-Benz Coupe/Convertible Forums > W215 CL Class

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 

Title goes here

close
video goes here
description goes here. Read Full Story
For the best viewing experience please update your browser to Google Chrome