waynesi

Hey guys,
I'm having trouble with the ASR/Limp mode activating on my '96 E320 (119,000 miles)
Changed brake lamp/pedal switch, K40 module, new battery, wheel sensors, all brake lamps functioning properly
ABS/ESR lamps have not come back, and speedometer is working again, but ASR activation is still occurring (don't know about cruise control, never use it)
It activates sporadically, engine cold or hot, moving or stationary, now I've noticed it'll activate when in park, I rev the engine, and I remove my foot from the accelerator
the RPMs don't decrease smoothly, there is kind of a bump or hesitation as the engine comes back down to idle speed, and the light will come up with the dreaded "BEEP" and limp mode is engaged.
could the problem be originating in the throttle or one of its components?
Also, is there a way to disable the ASR module? I don't drive aggressively nor do I drive the car in the snow... I don't want to go for a $2000 repair bill for a throttle body and replacement and would be happy with a cheap workaround just to keep the car from going into limp mode. Car drives fine otherwise, until dreaded ASR/limp mode activates.
I thought I had read that you can jump it out by connecting pins 1 & 6 but, I don't know if this works for the W210 or even where to find the pins to begin with?!
Any help or advice would be appreciated.
Thanks

ItalianJoe1

ASR (Acceleration Slip Regulation) is traction control, a function of the M/E and ESP modules, not it's own module, so it can't be bypassed or removed from the car. The fact that it's triggering in park when you release the gas leads me to think it's a throttle body or pedal issue, and would be better to fix than to try and hack a way around it, before it dies out completely and leaves you stuck.

waynesi

Do you think cleaning the throttle body and thoroughly lubricating the throttle linkage would help?

If so, is there a sticky or a procedure note (MB or otherwise) to follow?
I've heard that other people have fouled up things even worse by attempting to clean their throttle body incorrectly.

ItalianJoe1

No, you have an electrical component failing.

waynesi

Good advice, Joe.

I found a reliable technician up here that rewires and rebuilds throttle bodies.
I have to remove it from the engine, something I've never done, but I'm not afraid to try.
A procedure sequence would be helpful...

Would you know if there a MB procedure with a schematic or illustration I can find to help me with the TB removal procedure? Or maybe a video?
Where would be a good place to find something like that?

Thanks again for your input.

ItalianJoe1

I will try to link the docs when I get home, it's impossible from the work computer. However, it should be on the top of the engine and fairly straight forward to remove, just be mindful that everything in the car is 20+ years old and will break easily if you aren't careful, avoid prying on things or pressing down on plastic components where possible.

waynesi

Yeah, I've eyeballed the component, and it's below the air-intake manifold, which makes it pretty inaccessible.
I watched a video posted by a guy named Victor, where he shows how there is a segment of the manifold that can be removed, giving you a better field to work in when removing the throttle body.
One important tip he revealed is that once you're able to get your hands on the rubber boot, that connects the TB to the air duct that goes over the engine from the air filter box, you have to twist it
a 1/4 turn clockwise to release the boot from the TB (because there is a flange on the bottom of the boot) revealing the mounting bolts for the TB. I would have never figured that out on my own!

A step-by-step instruction for the procedure would be very helpful to me. If you're able to find it, I would be very appreciative. I've searched the internet myself, but so far, I've come up empty.
(except for Victor's video) .

Thanks again.

ItalianJoe1

Very little I can find in WIS regarding the M104 throttle body. This is the idle speed control valve, which should sit right above it? It shows removing the "resonance flap" unit right next to it, I'm assuming this gives you access.

Sorry, I have never worked on one of those engines, a bit before my time.

ptempel

Here are some procedure to take out the throttle body:

https://www.pelicanparts.com/techart...eplacement.htm
http://www.w124performance.com/docs/...A_rewiring.pdf
https://www.benzworld.org/forums/w12...ttle-body.html

I just searched for "m104 throttle body removal." This sounds like a known issue. From what I've read, pre 1998 throttle bodies have the same eco wiring as the old harnesses. So the wiring on the TB can decompose just like the harness. I also recently bought a 96 e320 with 96k miles. So I suspect that I will have to go down this road at some point as well. The TB should have a sticker with a barcode on it. It should have a month and year that it was made if you want to verify that its pre 1998. I also saw one article of a guy that replaced the wires on it. It looks fairly involved and I think they guy could not open the harness connector. So he ended up keeping the connector and soldering the wires individually to the wires going to it. Its probably easier (but more expensive) to just buy a replacement TB on ebay that has 1998 or later date. I also heard that rebuilt TBs have not worked for some folks. But that's another route to send your out for it to be rebuilt.

waynesi

Thank you both for your replies!!!

I just printed everything, with photos, and will be attacking this problem next week...
When I get the TB rebuilt, rewired and reinstalled, I'll post back to let you know the outcome.
Thanks again,
Wayne

waynesi

Hey Guys,

So I bit the bullet and bought a rebuilt throttle body from Autohaus AZ. It was a bear to install. The connecting hose from the TB to the Plenum was the most time-consuming
part of the job.
Anyway, got it in and started it up and the ASR light came on almost immediately. I also noticed the idle speed was pretty high.
Is there a procedure for the throttle to relearn the open and closed position of the throttle? Do I need to do anything else after replacing the TB to try and get this car running right again???
I'm about to give up and junk the car at this point. The parts bill totaled $725 and doing the job wasnt easy. I'm feeling frustrated and defeated at the moment.
Please, if anyone has advice, I would surely appreciate it.

Thanks again to the people who responded to my original post with attachments and advice on the procedure. Got it done, but somehow I'm still having a problem.

Please help!

Wayne