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ABS BAS ESP Lights Issue Check-list

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#21 ·
Using the 38-pin chassis interface, get no trouble codes on my Vident Ilink400 scanner.
Click to expand...
No need to put the same response again. I do not think your scanner is scanning the modules (at least not the traction module). Otherwise you would have seen CXXXX type fault codes from the traction system. So unless you have a proper scanner you will not be able to access the module data.


Have 9.1V (>200V scale) coming out of the trunk plug that would connect to the wheel sensor, not sure what that should be
Click to expand...
. If in the same location, this is most likely for the brake wear sensor (which is really a switch).

Your main problem is the brake lights not coming on. I believe the ESP/BAS/ABS lights coming on is the consequence, as the traction module monitors the switch pair inside the brake light switch (there are two switches, one is normally open, and the other is normally closed). When you press the brake pedal, NO switch (THE BRAKE LIGHT SWITCH) becomes closed. and the NC switch (THE TRACTION SWITCH) opens. If this does not happen, you will get an the ABS/ESP/BAS lights to go on.. If the brake light switch gets power from the Illumination Control Module (ICM) (through fuse 2), and it does close when you press the plungers, the only thing left is the return wiring (back to the ICM), and the K55 relay contacts in series with this wiring.
 
#22 ·
1) Relays labelled after fuse bank: A (thin/narrow black), B (green), C (5-prong yellow), D (5-prong yellow), E (5-prong yellow), F (4-prong black) & G (no relay). These all seem to be stock Mercedes relays. My replacement ones (#4 below) are all black.
2) Is K55 four-prongs? Removed this 4-prong relay from F slot (Slot C, D & E have 5-prong relays, 87a in middle), jumpered 30 to 87 as lugs are 30, 85, 86 & 87, get LED lit no ignition on & no brake lights (BL's).
3) Removed relay from E slot (forward of fuse area and in-line with F), jumpered 30 to 87a, no light @ LED (key on or off), no BL's. Jumpered 30 to 87, led lights up when key only, no BL's.
4) Replaced all relays one at a time and all together using HELLA relays, still no BL's, ABS, BAS/ESP ulluminates after brake pedal actuation.
5) #2 Fuse is good but swapped with one from trunk fuse panel, is not loose in slot, still no BL's.
 
#23 ·
Is the ICM an accessible item to check? Is this related to the headlight control switch. I guess Ill have to go to my smog guy and see if his scanner can run the traction modules. He uses a Snap-On scanner and it'd probably be a tad cheaper than the dealer. I sure do appreciate you direction and help so far, thanks...
 
#24 ·
stevony6 said:
1) Relays labelled after fuse bank: A (thin/narrow black), B (green), C (5-prong yellow), D (5-prong yellow), E (5-prong yellow), F (4-prong black) & G (no relay). These all seem to be stock Mercedes relays. My replacement ones (#4 below) are all black.
2) Is K55 four-prongs? Removed this 4-prong relay from F slot (Slot C, D & E have 5-prong relays, 87a in middle), jumpered 30 to 87 as lugs are 30, 85, 86 & 87, get LED lit no ignition on & no brake lights (BL's).
3) Removed relay from E slot (forward of fuse area and in-line with F), jumpered 30 to 87a, no light @ LED (key on or off), no BL's. Jumpered 30 to 87, led lights up when key only, no BL's.
4) Replaced all relays one at a time and all together using HELLA relays, still no BL's, ABS, BAS/ESP ulluminates after brake pedal actuation.
5) #2 Fuse is good but swapped with one from trunk fuse panel, is not loose in slot, still no BL's.
Click to expand...
Musical chairs!
 
#25 ·
The K55 is a 5 prong relay, at least that is what the diagram shows.

Have a look at the diagram attached.

1)Locate N7-1 (in U153 (which is for W208, your car)

2) Start from pin designated with 15 (that is circuit 15, where the power comes from when you turn the key to position 2.

3) Follow it through the K55 contact to the S9/1 contact (closed when brake pedal is pressed), then back to N7-1.

This is your brake light activation circuit.

You can do the following:


1) Remove brake light switch
2) Turn the key to the ignition switch position 2.
3) Measure the voltage between the terminal where the black/white wire comes in, and chassis ground (metalwork) You should read 12V (battery voltage). If you do not, either the ICM (which is the other name for the headlight control module) is not supplying the voltage, or the K55 relay is open, or some wiring issue (check the wires for pinches near the brake pedal).

If you have 12V at the black/white wire, then if the brake switch (s9/1) is fine, you have a problem with the return wiring (shown with black color) going through the X47 connector block.

Note: The fuse panel at the side of the dash is integrated with the ICM.
 

Attachments

#26 · (Edited)
stevony6 said:
1) Relays labelled after fuse bank: A (thin/narrow black), B (green), C (5-prong yellow), D (5-prong yellow), E (5-prong yellow), F (4-prong black) & G (no relay). These all seem to be stock Mercedes relays. My replacement ones (#4 below) are all black.
2) Is K55 four-prongs? Removed this 4-prong relay from F slot (Slot C, D & E have 5-prong relays, 87a in middle), jumpered 30 to 87 as lugs are 30, 85, 86 & 87, get LED lit no ignition on & no brake lights (BL's).
3) Removed relay from E slot (forward of fuse area and in-line with F), jumpered 30 to 87a, no light @ LED (key on or off), no BL's. Jumpered 30 to 87, led lights up when key only, no BL's.
4) Replaced all relays one at a time and all together using HELLA relays, still no BL's, ABS, BAS/ESP ulluminates after brake pedal actuation.
5) #2 Fuse is good but swapped with one from trunk fuse panel, is not loose in slot, still no BL's.
Click to expand...
Hmm, I guess I was wrong in assuming the K55 location is in the same place as the W210. I had a look at the component location diagram which is really for W202 (but maybe similar for W208). The K55 relay location is shown "somewhere", and my guess is it is at the footwell of the passenger side.

Have a look at figure 2.

STAR TekInfo


The codes you would expect with the traction :

STAR TekInfo



EDIT: It is at the passenger footwell (with the help from our Russian friends)

http://w208.info/repair/electric
 
#28 ·
INTERESTING THREAD.... MY BAS/ESP ABS LIGHTS ON WITH CAR START, BRAKE LIGHTS ONLY WORKING ON THE MIDDLE LIGHT IN THE REAR WINDSCREEN.....

DONE:
FOUND A LOOSE CONNECTION IN THE TAIL LIGHT ASSEMBLY....WHICH I FIXED..... BRAKE LIGHTS NOW WORKING....
TESTED THE WHEEL SPEED SENSORS ALL GAVE A READING OF 1.79-1.86 OHMS....


A LITTLE BACKGROUND INFO: MY TRANSMISSION GOES INTO LIMP MODE WHILE DRIVING, WHICH I RESOLVE BY RESTARTING.... THIS LIMP MODE OFTEN OCCURS WHEN I NEED TO SLOW DOWN ON BAD ROAD PORTIONS....AND IF I MAKE A SUDDEN U-TURN MY GEAR SHIFTS VIOLENTLY LIKE A CAR WITH FAULTY WHEEL SPEED SENSORS.... I AM ON THE VERGE OF REPLACING THE TRANSMISSION, BUT I WANT TO FIX THESE ABS/BAS/ESP ISSUES FIRST....


THANKS MRBOCA FOR THE JOURNEY SO FAR
 
#29 ·
Final Brake light fix

So when I first started having this trouble (no brake lights, ABS ESP trouble lights on dash) checked the brake light switch plug for power and the fuse and had power. Replaced fuses, BL switch and ESP module ($40 used, now have an extra). Turns out after going to third mechanic and this time paying $150 for full diagnostic, was bad connection in headlight switch/fuse panel assembly. Campbell Mercedes Repair in San Jose, Ca finally found the trouble, using the very expensive Mercedes diagnostic laptop. Should've gone there first as I purchased $100+ bucks worth of parts that are now spares and countless troubleshooting hours on an intermittent trouble. Know a lot more about the car now though. Thank you to all those who were part of that path to this solution...
 
#30 ·
Hi all.

I discovered that my brake light switch was faulty after assistance from your posts. Instead of replacing it I cycled the switch plunger rapidly about 20 times. I repeated that after spraying WD40 (actually Q20 spray being in South Africa) into the switch. That did the job and the switch has functioned perfectly ever since. I waited 2 months before I decided to post this so it wasn't just a momentary fix.

Cheers
Mark
 
#32 ·
Hi all I have the same issue as described above. My car is a 2003 UK model e320 CDI wagon following symptoms
1 start the car no warning lights sometimes the warning lights dont appear but when the do it BAS ESP and ABS warning as soon as Brake pedal is depressed
2 Brake light stop working in conjunction with these errors.
3. Brake light switch checked and swapped the one from my 2003 S Class ( same part number on switch ) Error did not clear.
3. Checked the fuses (Fuse 9) on my car for the Brake Lights and upon wiggling the fuse the Brake lights would start working and them dim out to the point they were filckering!
4 So I have removed the ICM to check the connections on the back as I believe as the above post that my issue is related to a bad fuse seat connection.

I am going try and repair the connection following strip down of the ICM to reveal the wiring inside so it can be checked.

I will update as to the fix!
 
#33 ·
mrboca said:
One more thing that can cause the brake light problem is the K55 relay which is installed in series with the brake light switch in series for cars with the ESP. It is to prevent the brake lights to be turned on when the ESP is activated, and you press the brake pedal.

The location of the K55 relay is likely in the same place as a in W210 which is on the driver's side fuse and relay module (the black relay).

You could whack the relay when someone presses the brake switch, and see if the lights come on. Or you could pull it out and and put a jumper between 30 and 87a contacts temporarily and press the brake switch with the ignition switch in position 2, and check the brake lights. I believe the relay has single pole double throw type so there would be 87 and 87a contacts. 30 and 87a must be normally closed, and 30 and 87 is normally open. When ESP is active the NC contact opens to cut the brake light circuit. If the relay is bad, then the NC contact may be open.

Also double check that the fuse #2 is not blown.
Click to expand...
There are 7 relays in driver's side fuse and relay module, but there is not K55 relay (my model E240 2001). Please show me the location of K55 relay. Thanks!
Image
 
#35 ·
#39 ·
K55 is normally closed. If open, you will not get any brake lights coming on. The ESP module opens the relay when the ESP is activated to suppress brake lights coming on. The ESP module may be sensing that the K55 is not present by monitoring the coil side of the K55, and generating a fault code. You should get the ESP module scanned to find out exactly what the fault and problem is.
 
#40 ·
mrboca said:
K55 is normally closed. If open, you will not get any brake lights coming on. The ESP module opens the relay when the ESP is activated to suppress brake lights coming on. The ESP module may be sensing that the K55 is not present by monitoring the coil side of the K55, and generating a fault code. You should get the ESP module scanned to find out exactly what the fault and problem is.
Click to expand...
"The ESP module opens the relay when the ESP is activated to suppress brake lights coming on". Why OFF brake light when the ESP is activated?
 
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