WOT enrinchment LH for 400E

[bgalakazam]

So I read a lot on this famous LH module and the ~10hp gain for using it on the 500E's. But since the compression ratio is different on the 400E, is the gain still 10hp or less?

I am asking, because I have a 1993 400E and this is one of the few things that may get some more power out of it. It's listed as 275hp (at optimum RPM) in the Mercedes booklet, but I am not sure that is the case as I read it's slightly lower for USA models.

So, some of the questions:

1. Is this the correct part for a 1992 LH module for a 400E - 014 545 15 32 ? Is it different than the one for 400SEL?
2. How easy is it to reset the learning without a digital scanner?
3. If you did the swap, was the actual gain at full throttle 10hp or less?
4. Is 275hp the max hp at optimum RPM as my booklet states?

Cheers

 

[gsxr]

1. Yes, 014 545 15 32 is the correct p/n
2. A hand-held blink code reader is required to reset adaptation, if you don't have a scanner
3. Dyno showed about 12hp to the wheels, est 15hp at the crank
4. The published data is questionable for 1992 400E models, but 275hp appears to be accurate for 1993-95 models.

 

[bgalakazam]

For the reset, this is all I found for manual reader, is it accurate?

To reset and reactivate the module :
1.Read and clear all fault codes
2.After display of 1 (No faults present) short the diagnostic plug (pin 8 for 16 pin diagnostic socket, pin
4 for 38 pin diagnostic socket) to ground for 6 to 8 seconds
3.Switch ignition off and wait at least 5 seconds
4.Turn ignition on, wait minimum of 10 seconds then restart engine.

 

[gsxr]

The official MB documentation says:

Resetting LH-SFI Control Module's Self-Adaptation Feature to Mean Value
After the

 number 1 appears on the [blink code reader], press button for 6 to 8 seconds.
Ignition: OFF and wait 30 seconds.[/QUOTE]

[URL="http://www.w124performance.com/docs/mb/diagnostics/DTC_List_W124_M119.pdf"][U]Click here[/U][/URL], see page 6. I always wonder where people find these other procedures...

:scratchchin:

 

[bgalakazam]

It's been running kind of rough and the shifting is sometimes sporadic. I guess it's normal. How long does it usually take to readapt? Any number of "trips"?

 

[samiam44]

It's been running kind of rough and the shifting is sometimes sporadic. I guess it's normal. How long does it usually take to readapt? Any number of "trips"?

That's weird- do you have any codes on the other pins- EZL perhaps? I'd drive it a 100-200 miles and then re-check all the pins to see if any codes come up.


Michael

 

[gsxr]

It should not run rough or sporadic. That is not normal. The adaptation usually adjusts within about a dozen or "trips" (cold start to fully warmed up). Sometimes it can take several thousand miles to fully adjust, especially on the .034 where you don't spend enough time around ~4000rpm under high load to set the upper adaptation value.

Make sure you don't have the infamous fuel pump relay clicking... pop up the rear seat cushion and start the car, the relay should not be clicking. This could cause a rough idle, but should not affect shifting.

 

[bgalakazam]

Well I took 1 short drive, not a dozen. The fuel pump was checked not 2 weeks ago. All I did was reset as per the 6-8 second hold via blink reader. I guess my English was too "strong". By rough I didn't mean like when I was running on 4 cyllinders. Just that the punch isn't there and downshift is slower.

 

[gsxr]

AH, got it. In that case it may take a bit for the adaptation to adjust. If the O2 sensor isn't recent, I'd grab one of those $45 specials from Rock Auto while they're still available (more info posted in a different thread).

 

[bgalakazam]

Brand new Bosch, < 100 miles. Oddly enough, dealer said it oscillates on 800MV to 60MV, but stays at 60MV (lazy). No blink codes.

 

[gsxr]

Brand new Bosch, < 100 miles. Oddly enough, dealer said it oscillates on 800MV to 60MV, but stays at 60MV (lazy). No blink codes.

The dealer is correct. It should oscillate once the engine is at operating temp. Pop in your old/stock module for comparision. If it's not... something is fishy. Sounds like you have a digital scanner so you can view the live data...?

 

[bgalakazam]

I have a blink scanner only... been meaning to get a Chinese STAR reader... but recent dental problems kept me away from that. Also, I am running the stock module, but it was never reset adaptation, especially after the driving on 4 zyl for some time. So I decided to reset it.

I took a few more "trips" meanwhile and car is getting better I think. The worst was the 1st drive.

Any way to check the O2 sensor myself? I don't have a place to lift the car and no digital scanner. No fault codes since my ignition coil was replaced, I check almost daily.

 

[gsxr]

There's no way to check it without viewing the live data on a scanner. But if it's almost new, it should be fine.

 

[bgalakazam]

Anyway, it's beyond my original query. Thanks a lot, though! You seem knowledgeable about these guys. I will get the WOT enrichment module on that "next" paycheck... right after the rotors and caps

 

[bgalakazam]

Reviving thread for an additional out of the random question(s). In NA, the 600SEL came as 402hp in 1992. 1993-1999 S600 it was 389hp due to WOT enrichment removed.

1. Will a swap from the 1992 version work on the 1993-1999 ?
2. Does it matter that the transmission was changed to electronic for 1996-1999 ?
3. Is one of these the correct 600SEL LH module: 012 54563 32 , 014 54519 32 ?

 

[gsxr]

The 1992 M120 LH module should work in a 1993-1995 M120 car. It will not work in 1996-up because those models have completely different engine management.

Both of the part numbers you listed should have WOT enrichment for the M120 V12. Remember that you need TWO modules, and it would be best if you had two of the same part number...