M104 cold start issue

[Seangbadee]

Lately when I go to start my 95 E320, after a period of being parked for hours, I get an initial high idle that lasts for less than a second. When I switch the engine off and start again, the idle is normal. The car runs very well and the only issue is the startup.
I searched the internet and found this article

03/95-2 M104 WITH HFM INJECTION SYSTEM​

​

In case of customer complaints of high idle (approximately >2200 rpm) for a very short period of time (< 1 second) immediately after cold start, an updated EA/Idle control unit is available from our PDCs. The updated control units can be identified by a software production date of "SW 43/94" and higher stamped on the housing in the area of the barcode label. The following control unit part numbers are affected:​

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Electronic Accelerator Control Units (E-GAS) Part No. ​

124 545 65 32 - E320​

129 545 05 32 - SL320​

140 545 49 32 - S320​

202 545 01 32 - C280​

​

Idle Control Units (T/LLR) Part No. ​

124 545 55 32 - E320​

129 545 19 32 - SL320​

140 545 52 32 - S320​

202 545 43 32 - C280​

Has anyone had similar issues?

 

[geraniumtr]

Yeah, its happened on my 94 E320 but very, very infrequently. Only on a cold start. I haven't researched the issue since it rarely happens and my car runs great otherwise. I chalked it up to an engine management glitch. Looks like 65 32 is available at $500 ( discount price ) while 55 32 is NLA.


Regards,

Peter Weissman

 

[gsxr]

Sean, can you check your T/LLR p/n and date code to see if it's affected? Might be able to locate a suitable replacement on eBay with the new/updated software? For example this one produced in late 1995. Both W124 units (with/without ASR) appear to be NLA per MB Classic.

 

[Seangbadee]

Sean, can you check your T/LLR p/n and date code to see if it's affected? Might be able to locate a suitable replacement on eBay with the new/updated software? For example this one produced in late 1995. Both W124 units (with/without ASR) appear to be NLA per MB Classic.

This is mine. I need my magnifiers to see the numbers clearly. I see 08/95, but not the other numbers in the TSB

 

[gsxr]

This is mine. I need my magnifiers to see the numbers clearly. I see 08/95, but not the other numbers in the TSB

I didn't see the number specified in the TSB either. These may display in the live data from a digital scanner, which I'm guessing you don't have access to.

 

[Seangbadee]

This is a picture of mine after I removed it from the car

 

[gsxr]

The photos are helpful. Although there isn't the software version on the label as specified in the TSB (need a digital scanner to view this), the "K number" is another indicator of software revision. Your car has K-07, mfd in Feb-1995. I found two newer versions, K-08 and K-09. Looks like the change from 7 to 8 was in mid-1995, then the change from 8 to 9 was in late 95 or early 96.

If you want to gamble on this as the permanent fix, I'd get one of the newer versions. You have to look at the pictures of each module for sale, hunting for the newer software / K-number. I suspect K-09 (produced Feb-2000) may be the latest/newest software. No affiliation with the sellers below, also not positive they have the lowest price for the latest version:

K-08 (Oct-95) for $120: https://www.ebay.com/itm/125431299874

K-09 (May-96) for $200: https://www.ebay.com/itm/165406884663

K-09 (Aug-99) for $200: https://www.ebay.com/itm/165197295049

 

[Seangbadee]

The photos are helpful. Although there isn't the software version on the label as specified in the TSB (need a digital scanner to view this), the "K number" is another indicator of software revision. Your car has K-07, mfd in Feb-1995. I found two newer versions, K-08 and K-09. Looks like the change from 7 to 8 was in mid-1995, then the change from 8 to 9 was in late 95 or early 96.

If you want to gamble on this as the permanent fix, I'd get one of the newer versions. You have to look at the pictures of each module for sale, hunting for the newer software / K-number. I suspect K-09 (produced Feb-2000) may be the latest/newest software. No affiliation with the sellers below, also not positive they have the lowest price for the latest version:

K-08 (Oct-95) for $120: https://www.ebay.com/itm/125431299874

K-09 (May-96) for $200: https://www.ebay.com/itm/165406884663

K-09 (Aug-99) for $200: https://www.ebay.com/itm/165197295049

View attachment 152659
View attachment 152658

I’ll check them out. Thank you

 

[Seangbadee]

I’ll check them out. Thank you

I got a used ICM with a later production date, and installed it (I disconnected the battery), but the initial high idle was still there.
The surprising thing is that when I went for a test drive, I noticed that the harshness in my gear shifts are gone. The shifts are noticeably much smoother than before.
I’ll watch and see how the startup goes this evening.

 

[M104-AMG]

Does the HFM M104 allow for adaption clearing or setting ? When I had my indepedent install a new Throttle-Body Acuator (TBA) on the C36 M104.991, I also get high-idles on first start, and somehow she doesn't seem as strong as she used to.

TIA,
neil

 

[195910]

Does the HFM M104 allow for adaption clearing or setting ? When I had my indepedent install a new Throttle-Body Acuator (TBA) on the C36 M104.991, I also get high-idles on first start, and somehow she doesn't seem as strong as she used to.

TIA,
neil

I should be possible to clear the adaptations just like the M104 ME. Plus the system needs to learn the TBA positions.

 

[Seangbadee]

I should be possible to clear the adaptations just like the M104 ME. Plus the system needs to learn the TBA positions.

Unfortunately, I do not know

 

[M104-AMG]

I should be possible to clear the adaptations just like the M104 ME. Plus the system needs to learn the TBA positions.

Do you know the procedure on how to do this via HHT ?

neil

 

[195910]

Do you know the procedure on how to do this via HHT ?

neil

Hi, its my first M104 and its a Bosch ME. In my case you just need to switch on the ignition in position 2, leave it on for 3 minutes (5 just to be safe) then switch it off. During that time you will hear the throttle valve moving to learn the stop position.

Should be the same for the HFM, I don't remember reading a different procedure.