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ML55 - Stiff Steering - Faulty Traction Control Module?

88K views 183 replies 29 participants last post by  johnathan1 
#1 ·
Hello everyone,

Is there a way to temporarily disable the traction control module (BAS/ESP Module) on my truck?

The reason I ask is I am suffering from a stiff/heavy power steering.

There are a number of reasons for this but these are the ones I am currently considering:

  • Power steering pump
  • Power steering rack
  • BAS/ESP (Traction) Module

I have already changed the PS pump.

The steering rack may be next, once I order it from the US and it arrives here.

In the meanwhile:

The ML55 is equipped with speed sensitive steering which is meant to stiffen the steering as speeds increase and the system works by processing relevant signals/information from the BAS/ESP (Traction) control module and adjusting the steering assistance as required.

I'm currently working on the theory, perhaps misguided, that the traction control module is faulty and sending the wrong information to the sensor?/parametric valve? in the steering rack making the steering stiff and requiring an awful lot of effort.

If that is the case, I was wondering whether it may be possible to disable the traction control system temporarily to see if that fixes my stiff steering.

I don't want to purchase the traction control module ($780) and it turns out not to be my problem so I must eliminate all possibilities.

The next theory is in relation to replacing the power steering rack which is no cheaper - it retails from between $1000 (reconditioned) to $1800 (New).

Witek and 43sqd have been very kind in providing me with information to help me solve the problem and I attach the following documents which have influenced my thinking in this regard.

Please help me.:crybaby2:
 

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#83 ·
Just to update you all on the issue of the Y10 (speed sensitive steering solenoid valve) being capable of replacement as a SINGLE part:

YES, it is possible to replace it as a single part.

There is no need to buy a whole new steering rack.

Also, the proportioning valve mentioned elsewhere in this thread is NOT the same part as the Y10 (SPS Solenoid Valve).

I was able to purchase the Y10 (SPS solenoid valve) from the following ZF Steering Systems outlet in Alabama:

POWER STEERING ASSOCIATES (Ask for Jeff Parker)
1961 4th AVE SW BESSEMER , AL 35022
ph-205.426.4327--fax-205.426.1188
1.800.915.4327
JEFF@POWERSTEER.COM

Part# 7039 442 250
Price $140.32

I have attached a picture of the part:
 

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#84 ·
Farid, the Y10 valve was never your problem. The problem was that the Traction Control Module was not delivering voltage to the valve at idle and low speeds.

This post is going to be misleading in that present & future readers will think that replacement of this valve will cure their problem (stiff steering) as it will not, unless the valve was damaged or the valve proved to be faulty following electrical tests.
 
#86 ·
James, I know my problem is the traction control module.

I never said that this part was my problem or has solved my problem or would solve anybody else's problem.

I simply said that the Y10 was capable of purchase as a single replaceable part.

If you read the entire thread you will see that both brettriehl & fkong asked specific questions (reproduced below) whether the Y10 (SPS solenoid valve) was capable of replacement as a single part.

.....that Y10 thing or whatever it is that you guys were mentioning... is that something that can be replaced separately or does that involve getting a new steering rack?
....Am I looking at a new Pump? or another Rack rebuild? Y10 SPS valve?

the Y10 SPS valve I looked at under the car, Im almost possitive it can be replaced without pullling the rack out...


Even Eric, a mechanic & moderator, expressed doubt whether the Y10 was a single replaceable part (below):

I am pretty sure you would have to change the whole rack to do this.
So I put it to you that far from being misleading, my post is informative of the fact that the Y10 (SPS valve) can be bought as a single replaceable part and from a supplier previously unknown to those concerned in this thread.

Now, will you admit that you did not read the entire thread and therefore ONLY YOU misunderstood my post in the context for which it was posted?

Incidentally, I recall that you were adamant that this part was not capable of being purchased as a single replaceable part.

You are NOT always correct!
 
#94 ·
Where would one find the TRACTION SYSTEMS CONTROL MODULE?

Where does this bugger live?

If the proper module is purchased and replaced, does it need to be 'coded' or otherwise paired with the car in order to function?

My steering has steadily been on the fritz and finally stopped delivering any power assist at all.

The rough winter killed one side of the rack and it needed to be replaced. It was removed, rebuilt, re-installed and aligned.
 
#100 ·
coding the control unit is very simple. There is only two or three questions to answer to get it correct so no need to read out the original computer. Then the unit needs a drive test run so it will learn the lateral and yaw rate sensors correctly. It is not a big deal to install and then drive to the dealer or someone with a compatible scan tool to perform the drive test and verify coding. Just don't expect the esp warning lights to stay off on the way to the dealer.
 
#101 ·
Please keep it simple, if a novice were to put it in test mode I am sure it will take days to put the light out by driving the car, a proper test must follow this way of thinking as I am sure you know and most owners do not know the procedure.
 
#103 ·
I am not being an A hole here, but 40 years of MB and running workshops, 33 workshops I look after here in China has taught me to think before giving advice. Whenever one of my techs says it is quite simple (to a customer, I cringe):D:thumbsup:
 
#106 ·
Hello Mike!:)

I am over the moon too; especially since I was so worried that even if I had purchased the traction control module I would not have had the dealer resources/equipment/expertise to have it coded to the truck as would be required.

Nice of you to notice that I have not been around the Forum much lately; I became disenchanted for various reasons including an increased workload in the office.

Hope all is well with you and the family too.:thumbsup:
 
#107 ·
im having this same problem. what i dont understand is why the power steering is changing with engine revs, not wheel speed... ie: if im pulling into my drive and the power steering gets tight, i can rev the engine and it will be easy again.... if it was the BAS unit wouldnt it make sense that speed sensitive steering would be read from the actual vehicle speed?
 
#111 ·
Any fault codes?
 
#113 ·
Hopefully it will not be as expensive as a traction control module replacement.

From what you say (and considering that the serpentine belt is okay) I would say that the next thing you MAY need to consider is your power steering pump.

I say this because you say the steering weight is engine-speed related.

It's just a hunch however and I'm no mechanical expert. :surrender:
 
#116 ·
Makes perfect sense.
 
#118 ·
It most certainly would as the steering angle sensor will now not be normalized and needs resetting, you know how to do this?
 
#120 ·
Yes with the engine running and turn it full lock each way several times.
 
#122 ·
Check the fluid level is OK and then drive the car for a few days.
 
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