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2000 E 320 Wagon + 2002 ML 500 SUV
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1,055 Posts
Discussion Starter #1
Hello All:

So I'm just finished replacing all the 4 ABS wheel speed sensors as I got a trouble code for LR a few months back. Replacing it fixed the issue.

I also was getting an intermittent BAS (one wheel braking) situation and knew it was setting a code - the YAW Rate Sensor has given trouble about 3x times in a years time, so that's part of this picture. But it would go a long while and no issues.

But while awaiting the ABS Sensors to arrive, all the sudden I got the '3 light Salute' + the Brake MIL + Beeping which is the YAW Rate Sensor (C1120 code) for sure.
Of Note is that a weird thing happened this time: The ML wouldn't shift out of 1 or 2 Gear - and bumping the Gear Shift in D wouldn't change up or down gears at all. And the 3 light salute - MIL Brake and Beeping the whole time in motion.
(Basically, ML goes down road, but undriveable as is)

So, I went ahead & replaced the ABS sensors AND scanned the entire system modules on this 2002 ML500 aka 163.175 - and showed these faults:

ME: P20CC Rough Road Detection by comparing wheel speeds - LF Wheel speed missing
P2068 >> P0720 Error Stored in EGS Control Unit - Output Speed Sensor Circuit Malfunction
Component N15/3 (ETC Control Module) memory has fault

ESP: C1120 - Yaw Rate Sensor - One wheel locks up
Clean Connnector or Replace Sensor

Also. after test drive & rescan: C1100 Left Front Axle VSS Circuit Fault
C1101 Right Front Axle VSS Circut Fault appeared

EGS: P2402 The Front Right Wheel speed of the traction system is implausible - The RF wheel RPM signal sent from the Traction system via the CAN bus is implausible

P2400 The Right Rear wheel speed of the Traction System is implausible
The RR wheel RPM signal sent from the Traction system via the CAN bus is implausible.

Now I expected some of those faults to clear once the new ABS sensors - all 4 were installed, but even after a test drive & effort to use the 'CARSOFT FOR MERCEDES' program on the laptop to both SCAN for these codes, and using it correctly to ERASE the affected modules, the ME, ESP and EGS ones, the codes remain, and the test drive is unsuccessful:

Exactly as before the ABS speed sensor R&R, when it went a bit crazy with the YAW Rate issue.

So, is there some trick to getting this Diagnostic system to erase the codes ? I've never seen this software fail to erase a code / module before.

I do suspect that I might have corrosion on the ABS Harness connectors - and like a dummy I forgot to use contact cleaner on each one - so I will GO BACK and unplug each & spray contact cleaner.

Also I probably need a new or good used YAW Rate Sensor - very minimum I'll pull this one out & clean contacts & re-install this one to make sure it's not just bad contacts.

I'm told it just under the armrest storage box -

Is there a trick like needing to ERASE faults from modules; then disconnect Battery overnight ?

Appreciate any input you can offer on this matter !

David in East Texas

( PS: I'm busy reading up on every reference I can find for these Codes...I need the ML back in action soon....)
 

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2003 C320 coupe, 2000 ML320
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725 Posts
Hey Dave,.. This might sound crazy, but take a look at your brake light switch.. They are a two part switch.. One for the light,.. one for the ABS,BAS,ESP, XYZ.. The only reason I'm saying this is, you're saying the tranny locked in place.. Maybe some how..the park lock is engaging while it's in gear.. Of coarse this is just an off the wall guess.. But if you run out of things to check, it might be something to look at.. Good luck..
 

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2000 E 320 Wagon + 2002 ML 500 SUV
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1,055 Posts
Discussion Starter #3
Thanks Bobby I already checked that, lol.

I'm thinking that the failure of the CARSOFTforMercedes to erase the codes is because the faulty part, the YAW or (Turn Rate) Sensor remains in place.

Does that sound right ?

I wish I had a more up to date Autel or ICarsoft scanner to read live data.

But the C1120 code does say "YAW Rate sensor fault" - one wheel braking.

My only option for a 'new part' is to buy a used one off Ebay.

It's part # A003 542 23 18
aka A163 542 6440

I suppose another option is to use electrical contact cleaner on both sensors.

Oh yeah in this whole picture there is another sensor a "Lateral Acceleration Sensor" mounted aside the YAW sensor.

I understand they both feed vehicle position data to the ABS ESP ETS control modules.

Not sure if that 2nd Sensor ever has trouble or not.

Thanks for any input anybody has.

The ML500 is sidelined until we get this licked !

Many Thanks - David
 

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2000 E 320 Wagon + 2002 ML 500 SUV
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1,055 Posts
Discussion Starter #4 (Edited)
I'm going to start a new thread with a more appropriate title, I didn't quite get this one right...
Ok new thead is here. I edited my rambling account to be more coherent..

 
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