Will a "bad" ETA damage modules? ('94 E420) - PeachParts Mercedes-Benz Forum

Larry Delor · #1 03-06-2007, 05:02 PM

Hello everybody!

As some of you might have seen, my E420 is having "issues". Yesterday I was informed that I should get a new LH module and a Base module. I was also advised that the ETA was going, and that I ought to get a new one.

Since the ETA uses the same half-ashed wiring that the harness used (replace it), is there a chance that a bad/going bad ETA can damage the aforementioned modules?

If so, then I would get a rebuilt ETA, or else I'd just be throwing good money away, and hunt for parts again.

Thanks!

-Larry

DRICHFL · #2 03-06-2007, 10:58 PM

Larry,

If the ETA is bad it just will not work. No such thing as going bad, either it does work or don't work properly. I have heard that ETA can take out other electrical items but only in the case of faulty or crack wires. Issues such as bad wiring harness could cause other electrical components to be harmed. It is possible to have a fuse blown first before you have a major electrical component harmed by the ETA. Most likely if your ETA is bad it is because of the worn gears inside the ETA if you don't have a electrical harness issue.

One way to confirm whether or not your ETA is working is to turn your ignition switch to the #2 position as if you are scanning codes. Then listen for the ETA to make a hi-pitch noise. The hi-pitch noise is the ETA's butterfly setting itself in the correct position to allow the engine to start with proper airflow. Look inside the ETA and see if the butterfly is adjusting itself by opening and closing.

If you don't hear the hi-pitch sound or see the butterfly adjusting itself then you may want to reset/reprogram the ETA. I can't remember at the moment how to reset the ETA but I will get back to you after I look it up. It goes something like turn your ignition switch on and stepping on the accelerator pedal but I will get back to you on that one.

Far as the Base Module, I rarely here of it going bad. Usually a fuse would blow I really doubt if your Base Module is fried. I continue to suggest that you scan each module to see if you get fault codes before buying a new modules.

JimF can really help you out on ETA I suggest contacting him. I had my fair share of dealing with ETA so before you purchase a new one make sure yours is definitely shot.

cool · #3 03-07-2007, 02:59 AM

the modules installed in an MB has proven to be a very reliable part that does not break easily, only when abused, what seems to be the problem of your car for you to decide to change the modules and the ETA (what made you come to the conclusion that these parts are bad? may I be of help? offshore mercedes benz dealership

JimF · #4 03-07-2007, 10:41 AM

Larry, with 160K on the '94 E420, the first that comes to me, is was the wiring harness replaced?? If not, I'd certainly start there. As you have read here, many cars where brought back from their apparent 'death' when it was replaced.

I've NEVER seen one of the modules go bad . . . and in time (12 years), my tech has maybe replaced one???? The DTCs that are generated point to a faulty EA but, in my experience, it's always something else.

A good scanner will help to read the codes; reset them and retake them to form a 'history'. When my ETA was going bad it pointed to the EA module as well as other items.

A bad wiring harness can, and HAS, taken it's toll on ECUs, so that's a reality.

I'd either have the ETA rebuilt or replaced provided the codes support that conclusion. MENU#24 shows the typical codes that you encounter when the ETA is bad or going bad. I recommend you start there and keep track of the generated codes.

Larry Delor · #5 03-07-2007, 02:48 PM

Quote:

Originally Posted by cool

the modules installed in an MB has proven to be a very reliable part that does not break easily, only when abused, what seems to be the problem of your car for you to decide to change the modules and the ETA (what made you come to the conclusion that these parts are bad? may I be of help? offshore mercedes benz dealership

Cool,

This link will show you the thread that led to my question in this thread.http://www.peachparts.com/shopforum/showthread.php?t=179793 Any help is always appreciated.

-thanks,

-Larry

Larry Delor · #6 03-07-2007, 02:52 PM

Quote:

Originally Posted by JimF

Larry, with 160K on the '94 E420, the first that comes to me, is was the wiring harness replaced?? If not, I'd certainly start there. As you have read here, many cars where brought back from their apparent 'death' when it was replaced.
A bad wiring harness can, and HAS, taken it's toll on ECUs, so that's a reality.

Hello Jim,

Yes, the harness was replaced last year (or maybe the year before). Back then, I had a problem for a while with CAN communication.
Late last year the Air mass sensor was replaced, and things were good for a while...then it didn't want to start when medium warm. The day I took it in to get looked at, it would alternate between barely running or not at all. See my link to my other thread in my reply to cool above.

I'll double check your menu when I get home.
Thanks!

-Larry

Larry Delor · #7 03-08-2007, 04:47 PM

After doing some thinking and reading, I've decided to get a rebuilt ETA.
Why? Well, because Mercedes-wedontknowanythingaboutcrappywiringharnesses-Benz used the same wiring in the ETA's as well, and I'm not going to take any chances on the ETA ruining other parts, and my ability to use the car. Nor do I feel I can trust the car, especially in an emergency situation, unless I am sure that I have replaced all the parts that might contain the sub-standard wiring MB put into an otherwise great car.

I'll let y'all know what happens after the replacement. (If any of you want to know).

-Larry

JimF · #8 03-08-2007, 04:53 PM

Smart move! If you want to be sure before you send it in, take a very sharp 'Xacto' knife and carefully make a cut through the outside sheath for about 4" or so. Carefully spread the cut area open and I'll bet you ($0.10) that you will find crumpled, decayed wires. If it's the "original" ETA, the wires are history.

Larry Delor · #9 03-13-2007, 06:37 PM

The ETA arrived, and was installed. Still no worky, - now the ASR module is said to be bad.

If it weren't for the fact that I opened up the old ETA, I would've been a little skeptical of that diagnosis.

I opened the side of the ETA that has the gears in it - there is a little trapezoid board on there...the wires under it had NO INSULATION left! None. It's a wonder the car ran at all.

This, seems to answer my question posed in this thread. Yes, a bad ETA can damage modules. So far it is the ASR module that quit - we're not sure about the LH module.

Hope this thread helps somebody.

-Larry

JimF · #10 03-13-2007, 07:18 PM

Hopefully you can swap your EA Module (N4/1) with a working unit. That's what I'd recommend.

Larry Delor · #11 03-13-2007, 10:26 PM

Quote:

Originally Posted by JimF

Hopefully you can swap your EA Module (N4/1) with a working unit. That's what I'd recommend.

Thank you for your reply, Jim,

I'm not sure I understand why you think I should swap that one (N4/1).

Supposedly the code reader (a Baum model) claims the ASR module N30/1 is defective. Would a bad EA module give a false reading like that?

Maybe I should try throwing some holy water on it - that way if it catches fire, I know what the problem is for sure.

-Larry

JimF · #12 03-13-2007, 10:46 PM

In all of the ETA failures that I've seen, there are some DTCs that point to the EA Module.

Check my escapade (in MENU#24) with my ETA failure. The codes that were generated were basically three;
1) in the DM (#6 ISC faulty);
2) in the EA (#2 EA plus others faulty)
3) in ABS/ASR module (#30- CAN bus communication failure).

That's where my suggestion came from. . .

If you can also swap the ABS/ASR module, then by all means do so.

Larry Delor · #13 03-13-2007, 11:06 PM

hehehe... It was my reading Menu 24 that convinced me to get a new ETA

These ASR modules are not a plenty - I'd search for an EA module, but I don't have the part # (yet).

Larry Delor · #14 03-15-2007, 08:00 PM

I went and visited the car today.

I hoped that maybe the ETA had not been "reset" before anybody tried to start it. No dice.

Here is what I did notice:

*When turning on the ignition key, there was no whine/buzz coming from the ETA like there had been (no discernable movement either).
*When it did run, it ran all sorts of rich - the exhaust was plenty visible and the air reeked.

Are these symptoms of a bad ASR module or EA module? or both??

thanks!

-Larry

I forgot to mention... 3 base codes are coming up 6, 10, and 17

DRICHFL · #15 03-15-2007, 10:06 PM

Larry,
Where did you purchase your rebuilt ETA from? It is possible to get a bad rebuilt unit.