ETA issues - Limp mode

[carboRS2]

I have recently rebuilt my engine and had it back in the car this summer.
After re-connecting everything the car fired up and all seemed to be right but the ASR light in the dash.
It's in limp home mode and can't solve it.
First suspect was the ETA wiring because it was still the original from 1991 so I purchased a used one from 2006. No luck.
Then I changed the NSS because it was also the original one. No luck.
Then the ECU. That did not solve the problem but eliminated the error codes in pin 7.
Finally, last things changed are the TPS at throttle pedal and brake light switch. No luck either.

So situation right now is this:
Whith ignition on before fire up the throttle works properly. If I press the pedal the butterfly opens.
When I fire up the engine, as soon as I touch the pedal you feel something happens, idle surges to 1000-1100rpm and the pedal has no response until pressed hard.
When I check the error codes at pin 6 and 7 there are no codes. Just one blink.

I'm completely lost.

Anybody here has some idea? I have read all the threads related to ASR LHM and can't find something similar to this.

Could it be some kind of vacuum leak?

Any help is greatly appreciated.
Thanks



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[Eno]

Re: ETA issues

Check the E-Gas module also and the throttle sensor behind the gas pedal which has two wires.


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[carboRS2]

Re: ETA issues

Check the E-Gas module also and the throttle sensor behind the gas pedal which has two wires.

Thanks for the reply Eno.
My original E-Gas was throwing error code 12 (voltagle supply at circuit 87).
So I tried 2 different E-Gas, one from a W140 500 and the other from a W124 400. With both the blink faults disappear but the problem persist.

About the sensor in the pedal I replaced it yesterday with a brand new from dealer.

I have also adjusted linkage and I think it's ok. Otherwise I guess it would trigger the limp home even with ignition on but engine not running.

 

[195910]

Re: ETA issues

Is it persistent or only during warm up ?

 

[carboRS2]

Re: ETA issues

Is it persistent or only during warm up ?

It's persistent


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[Eno]

Re: ETA issues

Check the ASR module also.
If you are in the CAN box, remove battery cables before, remove all the modules, clean the dust down there and place all the modules back very firmly in.


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[gsxr]

Re: ETA issues

This will be VERY difficult to diagnose without a digital scanner to provide live data. You've already replaced most of the components in the system.

Do you have access to another vehicle where you can plug in the 2006 ETA for testing? Just because it's newer datecode does not guarantee it is good (although it should be.)

 

[carboRS2]

Re: ETA issues

I already tried that as well.
I found one of the connection a little sunk into the socket. So I had to dismantle all the box to put it back into place.

What I haven't tried is using another ASR module.
Maybe it's the only thing left to change.



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[Stevester 500E]

Re: ETA issues

...but the ASR light in the dash.
It's in limp home mode and can't solve it.
...Could it be some kind of vacuum leak?

I have had the ASR come up when I had a malfunctioning throttle cable (the white plastic screw was broken)
The broken piece was causing a fluctuation adjustment position. However, the car didn't go into Limp Home Mode, just the ASR light stayed on.

Could it be a vacuum leak? I am not sure what type of faults a broken breather hose to the ETA would cause.
But it is possible that when you twisted the ETA into position, the breather hose that is on the back of the ETA cracked at the junction. That would happen if the hose were very brittle.

 

[carboRS2]

Re: ETA issues

Could it be a vacuum leak? I am not sure what type of faults a broken breather hose to the ETA would cause.

I renewed the hoses because they broke all in pieces when I removed the old throttle body.

But I still suspect about it because it's the only thing that changes from ignition on (when it works) to engine fired up (when it stops working).

Maybe I'm wrong but if it works well just with ignition on it should be because the E-Gas is getting good signal from all the sensors.

And when I fire up the engine is when the vacuum is created.

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[gsxr]

Re: ETA issues

Vacuum leaks should not cause limp mode, that would only cause engine running issues. However, I'm not 100% certain... Klink?

 

[sheward]

Is that corrosion I think i'm seeing in those module receptacles?

drew

 

[carboRS2]

I'm considering to take to the dealer but it's 80km from where I live and I'm not very confident in current mechanics dealing with such an old model.
What do you think? Should I give them a chsnce?
And is it good driving 80km in this condition?

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[carboRS2]

Is that corrosion I think i'm seeing in those module receptacles?

drew

Where? I did not notice anything. Maybe it's the zoom that gives a white effect...

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[sheward]

Yes, it could be.

drew

 

[Stevester 500E]

I would not trust a mechanic that isn't familiar with the older m119's.
I would check to make sure the return spring on the ETA is hooked up.
And I would re-check the ETA linkages and throttle cable.

I'm considering to take to the dealer but it's 80km from where I live and I'm not very confident in current mechanics dealing with such an old model.
What do you think? Should I give them a chsnce?
And is it good driving 80km in this condition?

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[carboRS2]

It seems there's a Mercedes Classic Center in Barcelona.
It almost 200km trip from where I live. Can I drive the car so far in limp mode?

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[carboRS2]

Hi everybody. I retake this thread.
During these months the car has been parked with the ETA not working.
Meanwhile I have purchased a Star C3.

When I run the test with just ignition it finds no errors. I can also read live data.

When I start the engine it can't connect with EFP module.
I this normal?

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[gsxr]

When I run the test with just ignition it finds no errors. I can also read live data.

When I start the engine it can't connect with EFP module.
I this normal?

No, that is not normal. You should be able to view live data with the engine running.

Unfortunately I have no idea what the problem may be.

 

[carboRS2]

Thanks gsxr for the confirmation.
I have two other e-gas modules apart from the one installed right now.
I will swap them tomorrow and see if the lack of communication persist.

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[carboRS2]

I have finally solved the problem.
I contacted Victor from restoreyourmercedes.com who advised me to check alternator voltage.
And he was right. The output voltage was 18v.
That explains why the throttle was working with just ignition on (only battery supply) and as soon I started the engine (alternator supply) it stopped working.
There might be some kind of overvoltage protection and the general module disconnected the e-gas to prevent damage.
Hope this helps someone else in the future.


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[a777fan]

Wow. 18V?? Good thing the fault was preventing you from driving it or running it very long. That battery might have exploded.

Thanks for following up and posting the fix.


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