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2004 CLK500 (Wifes), (2) 2005 ML500SE, 2004 ML500, 2000 ML320, 2002 ML320
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79 Posts
Discussion Starter #1
Sorry for the novel, hope this helps someone in the future.
I purchased a 2005 ML-500SE to use as a winter vehicle, dealer repaired until 2017, not much repair details from owner I purchased from. After my standard new vehicle repairs and maintenance,
I test drove and above 25 mph the BAS/ESP ETS ABS warning lights, the Red brake warning light were on, and a loud warning beeping siren under the dash was on above 4 mph forward or reverse.
The ESP / ETS yellow triangle in instrument cluster flashing, and strange shudder after first starting engine and first putting in gear. While testing I also found that the brake lights were not working.

I have repaired the ESP system, and have driven this ML for 2 months and 1,377 miles problem free.

Test Equipment used: Autel MD802, Fieldpiece SC440 multimeter, SDS

WARNING: 2003-2005 W163 have a ATE Type 25 ESP ABS (N47-5) unit and 47 terminal harness coupler, earlier W163's have a ATE Type 20 ESP ABS unit and are not compatible with each other.

Scanned and I first tried to read as many posts on the forum with similar problems.

P20CC-8 rough road speed signal from ESP implausible. (P1999)
P20CA no CAN message for LR wheel speed, from ESP or message faulty.
P2401 LR VehicleSpeedSensor (VSS) signal sent via CAN bus implausible.
C1210 terminal 30 undervoltage.
C1122 LR VSS signal fault.
P1861 LR VSS signal sent from traction system via CAN bus is implausible (warning: this not a
function error of control module N15/5 (shift module) and does not justify replacement.
possible cause could be fault of ESP N47-5 module.)

Live streamed data from ESP module while driving. LR VSS has no signal.
Tested LR VSS across terminals, 0 ohms. Ordered LR VSS. Tested new VSS, 758 ohms, Installed.
Erased all codes, drove, same problems, same codes except a new C1120 LR VSS line monitoring.
Tested new LR VSS, 756 ohms and 2.18 volts AC while spinning LR tire.
Back probed N47-5 harness coupler at LR VSS terminals with .015" phosphor bronze wire. (806 ohms and 2.16 volts AC)
Removed left headlight, tested ground stud, cleaned all ground terminals, lifted windshield washer tank,
removed N47-5 harness coupler, removed harness protective mesh, closely inspected each wire with magnifier, no abrasions in protective mesh or on any wire. Tested voltage at main feed wires After 4 hours
testing battery seemed weak. tested battery (fair condition, thought maybe with the under voltage code, battery was problem).
Installed new battery, cleared codes. Drove same problems and codes, even under voltage.

While scanning the N47-5 module, communication was lost, voltage at module was 12.61 volts, then dropped to 0 volts. Installed new main positive feed wires and terminals, and new main negative wires
and terminals in the N47-5 harness coupler.

I then tested all of the VSS terminals on the N47-5 coupler moving the harness wires, while my son spun each tire. On the LF and LR terminals the volts AC readings changed to 0 at certain positions. I closely
inspected the N47-5 coupler. I found the LR VSS + wire and LF + wire were mostly broken approx. 1/2" behind the factory crimped terminals inside the original insulation. From the module side of the N47-5 coupler the terminals were
damaged by someone using too large of testing probes. I found the Green CAN wire only connected to its terminal by 1 wire strand. I removed each terminal and inspected or replaced any problem terminals one at a time.

I further tried to determine if somehow damage caused, but the terminals on the back of the coupler are not close to each other, no marks on wires insulation.??

Caution: The 43 N47-5 module male terminals are rectangle approx. (.025" x .041") so only use phosphor bronze test wire .020" or smaller. A straight pin is too large for the terminal.

Final repair: 8 new terminals for all VSS sensors in N47-5 harness coupler.
2 new terminals for both CAN bus
 

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2003 C320 coupe, 2000 ML320
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896 Posts
Hey Kustom,.. Thanks for sharing.. And if that doesn't work.. give it a few rounds of ACP.. ..
 

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2000 E 320 Wagon + 2002 ML 500 SUV
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1,065 Posts
Kustom1911:

Hey your 'novel' is a great read ! How did you know I was having similar issues ??

Not exactly but very close, one wheel braking, '3 light salute' and then just a week ago, EXACTLY what you said, all of that with Brake Light illuminated + incessant beeping above 4mph !

Plus, new this time, my tranny won't shift above Gear 2, and bumping the Tranny shifter it stays in D always - Of course this limits your speed & besides the beeping drives you crazy.

I know a bad or failing YAW Sensor is part of my isssue - got code C1120 + the LF one wheel braking occasionally.

But I was also needing to replace all the ABS Sensors, I had already gotten a code for a bad signal from LR one.
I just finished doing the last 3.

So, to review your comment:

"VSS terminals on the N47-5 coupler" do you mean the harness connector to each wheels' ABS Speed sensor ?

Do I misunderstand ?

Thanks for clairifying.

i do plan to check all ground wires - I ran across some other posts where a guy with these symptoms had a loose ground connection in the Passenger Side Fuse Box area.

So I'll check it & also the ground connection under the headlamp on Drivers Front, and you said the main harness connector to the ABS pump too.

Here is my post / thread where I list all the codes showing:


Appreciate your input more than I can say.... (wife wants her e320 back !)

David in Texas
 

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2004 CLK500 (Wifes), (2) 2005 ML500SE, 2004 ML500, 2000 ML320, 2002 ML320
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79 Posts
Discussion Starter #4
David in Texas, to clarify, the connector where the LR ABS (VSS) sensor plugs into is L6/3x1. L6/3 is LR sensor. L6/4 is RR sensor. L6/1 is LF sensor. L6/2 is RF sensor.

The N47-5 coupler i refered to is connected to the ESP / ABS module behind the Left headlight and behind the LF wheel well liner. The N47-5 module mounts directly to the
A7 ESP / ABS hydraulic unit on 2003 to 2005 ML's only. Your earlier model has the A7 hydraulic unit in the same place, but the ESP control module is mounted behind the underhood
fuse / relay box, in front of the Engine Control Module.

Another thing is the 2003 - 2005 have the brake release switch is part of the brake booster. 2002 and earlier have a pedal mounted brake light switch.

hope this helps.
 

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Registered
2004 CLK500 (Wifes), (2) 2005 ML500SE, 2004 ML500, 2000 ML320, 2002 ML320
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79 Posts
Discussion Starter #5
Bobby735, thanks, we have such great mentors on this forum, they deserve medals, it was the least i could do.

i am using my $ 900.00 after fuel, dinner for 2, 12 hours with my wife, and $ 43.00 in chicago tolls 05 ML-500 to haul my ACP. lol
it did not run, and the rf outer tie rod end could have broke loading it on the trailer, it was so bad. $ 1,300.00 and a lot of labor it is
outstanding. our family owns 6 ML's i take care of. Best Regards
 

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Dallas, Texas
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7,994 Posts
What is boils down to is that you took time to measure, look at actual values and identify the problem.

Most members here are just parts hangers.

Volt meter. What's that? My scanner told me there is implausible signal from R/R speed sensor. Let's just hang one on. Did not fix the problem? Must be a scanner. 🍺
 

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2000 E 320 Wagon + 2002 ML 500 SUV
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1,065 Posts
Kustom1911:

Thanks for all the tips, super helpful.

Wow, you're a 'fleet manager' with 6 MLs - if these rigs are as demanding as a 'rewarding wife' - then you sound (no offense !) downright polygamous, LOL.

I am challenged by just this 1 - but pray I gain the upper hand shortly, esp with the great help y'all have to offer.

So on the 2002 is the N47 module connector in a more protected location under fuse box ? Less vulnerable than the later ML ?

All the broken wires or terminal pins you fixed were in / next to that connector behind headlight, correct ?

Thx - David
 

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2004 CLK500 (Wifes), (2) 2005 ML500SE, 2004 ML500, 2000 ML320, 2002 ML320
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79 Posts
Discussion Starter #8
Yes, The 02 N47 module is more protected, but the harness and coupler on the ABS pump can still be corroded by a leaking windshield washer tank, grommet, or pump.
the harness abrasion chances are the same on each style.

overall I like the W163 series, i have my thoughts at times questioning MB engineers, like any brand. I have my list of improvements i change, and strict maintenance
schedule, they are not too bad to work on, safe and very capable vehicles.

Hope you are gaining on your problem, Best Regards
 
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