I need the chip with the upgraded software for the ECM-HFM. After through investigation, this is my diagnosis. Air/fuel mixture is too rich. This will takecare of the Check Engine Light and code 19.

I installed 205/60 tires and the spare is the original 195/65. What effect will it have on the diff if I install the spare tire?

I recently bought my 94 E320 with 58000 miles. I was disappointed by the engineering on this vehicle. Technology is form the 80’s, especially the electrical and engine cooling systems. I would not have paid $43000.00 for it in 94 but at $10500.00, it is not too bad. Ride is solid, fit finish and quality of materials is better than my Pontiac Montana. My previous car, a 2000 Nissan Maxima was one of the most reliable cars in the world, but the ride was jittery.

Engine Gasket, Both Aux fans and EGR valve were replace by the Mercedes Benz dealer before I bought the car. I replaced the Engine Wiring Harness and dealer is checking with the factory rep to get me a refund.

I have installed an Alpine MP3 CD changer, and as soon as I can upgrade the ECM, replace the Aspirator motor for the climate control sensor, change the Aux fan fuse from 15 to 25 A, my car will be in near perfect condition, well as good as Mercedes designed it!!!

I was surprised to learn that a little rattle form the drivers door was a fairly common occurrence in this model. I had always heard that Mercedes Benzes were built like a tank, rock solid and quiet, but I can hear various fans coming on and off, the AC is not very quite either. Transmission shifts are firm, GM transmission are smoother, but I drove it on a 630 mile and it was very comfortable.

Has anyone tried to install a five speed automatic in the W124? It sure could use a fifth gear. I was surprised to find that it did not have a lockup torque converter either.

But to summarize, I still like this car better than all my previous vehicles (Buick Century, Ford Taurus, Ford Probe, Mitsubishi Galant, Pontiac Montana, VW Passat and Nissan Maxima).

although mine is a 1993, our cars are virtually identical.

Who makes the chip with the upgraded software for the ECM-HFM? I didn't know one was available, or rather I didn't know that there was upgraded software.

I don't really feel my blower motor for the HVAC system is either louder or quieter than any other car I have owned, but I do feel that the highest setting on the blower is higher than any other car I've had the pleasure of owning. When you say your blower is loud, does it make a squeaking noise, or is it loud, like a 747 taking off?

My aspirator fan motor went out, too, and it was squeaking or chirping like a bird. It's located behind the passenger side air vent, and it's not terribly hard to do (after watching my mechanic do it in a few minutes).

About the EGR valve - it's a good thing it was replaced as the original ones had a tendency to stick. There was a TSB in this regard and the part was updated. However, a more common occurence with the EGR system is a blocked pipe. Steve Brotherton wrote an article with pictures in the DIY link at the top of the page. There is a small diameter metal pipe that exits the EGR valve on the passenger side of the engine near the end of the engine block. It goes around the back of the engine, between it and the firewall, and then enters the intake manifold. This small pipe plugs up with carbon from EGR vapors. When a code is tripped, many technicians simply replace the valve, thinking it is stuck closed, when all the while the pipe was plugged up. It is a good idea to clean this pipe at 60,000 mile intervals.

These cars are built like a TANK, and it is the most solid and enjoyable car I have ever owned, and I've owned many Japanese and American cars. However, I don't believe I've ever heard about a rattling in the passenger door. Whatever problem you are experiencing, I can assure you that it is not characteristic of this model. Of the 100 or so W124 owners I've met and talked to at social events with other members of this site and with guys from the local chapter of the Mercedes Benz Club of America www.mbca.org , I can't recall that complaint once. If you try the search function, you may be able to find mention of it in the archives.

Good luck and feel free to bring up any other issues. I seem to have encountered every problem with this chassis (1993 300E 3.2 / 1994-1995 E320) in my car, and I might be able to help you / save you some money in the future.

Happy motoring,

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

Door rattle complaint from the 94/95 was a common fault with the mounting screws for the upper wood interior panels
Archieves...

One of the things you have to understand about the W124 chassis was that it's initial design was NOT from the 1980's. It was from the 1970's!! Mercedes begun the 201/124 design in 1979!

Though the car was highly evolved by 1995, it had lived a long life and was being sold in a world dominated by newer cad/cam designs and big changes in manufacturing processes.

Go find me a Japanese 1979 design that was still a desireable car in 1995!

__________________
John Shellenberg
1998 C230 "Black Betty" 240K

http://img31.exs.cx/img31/4050/tophat6.gif

94 E420 Check Engine Light On
ATTN TECHS

The attached two links refer to the DTC 19 and rich fuel mixture for an E420 LH-SFI. I need the update for an E320 HFM-SFI.

Mercedes Benz dealer diagnosed my problem as follows:
Function Test W/HHT/ HFM Codes 035 O2 Sensor
Stop/Mixture to lean, 051 Self Adapt too rich, Replace O2 sensor still at Rich stop, Replaced Mass Air still reads flat, Replace over voltage relay, reading still flat, Diag Faulty HFM Control Module $2200.

I would first check the fuel pressure regulator [ pressure test when
running]
Also , take the vac hose off reg and see if any gas is present there [ indicating bad reg diaphram].
You also want to look for vac leaks....

I will go over the problem I am having in more detail. The Check Engine light comes on after a few days of resetting it. I always get two codes: one of them is 19 (Fuel injectors open/short circuit or Emission control adaption in ECM at limit) and the other one at times is 3 (Lambda control inoperative) or 4 (Air Injection inoperative).

The vehicle operates flawlessly. Smooth idle, 22 MPG fuel ecnomy, no problems in starting, engine temperature stays between 80 and 95. Everything works fine.

I looked up the information copied below, but I do not think that it applies, because the dealership installed an ECM from another vehicle, and they claimed that everything was working fine after that. I believe that it is a minor issue; otherwise, engine performance would have suffered.

A different Mercedes Benz dealer after replacing the wiring harness was not able to find anything wrong with the vehicle, but the Check Engine light comes on.

60K miles service has been done. The car has new spark plugs, fuel filter, air filter, transmission fluid etc.




Mixture Preparation Self-Adaption


The Lambda control system determines fuel injection duration precisely so
that the fuel/air ratio is kept constant at Lambda level 1 (equals 14.7 kg
air to 1 kg fuel) under all operating conditions.

Should malfunctions occur in the form of:

Intake air teaks,
Injector wear or carbon build-up,
Engine wear,
Contact resistance in mass air flow sensor,
Defective diaphragm pressure regulator,
Defective purge switchover valve,


the engine control module automatically corrects the fuel/air mixture by
adjusting the fuel injection duration.

The degree of correction is constantly calculated and permanently stored if
the following conditions are satisfied:

Engine coolant temperature < 52 °C at start.
Engine coolant temperature between 80 and 100 °C while driving,
Intake air temperature between 0 and 55 °C.


Air/fuel mixture self-adaptation occurs at idle and under partial load. The
maximum degree of correction towards rich or lean is 25%. After fuel
injection system or engine repair work is performed, the engine control
module will automatically adapt itself after approx. 10 trips. After
eliminating a malfunction or after trial installation of an engine control
module from another vehicle, the self-adaptation feature must be reset (see
"Resetting and Reactivating ECM Memory").

Self adaption has +/- limits ..
So, if pressure regulation is too high for correction limits , a code will come up.
Same for vac leaks..

Your car has access to the other modules , so if a code 19 CE lamp comes up, you should go to pin # 8 with a led/sw and see what codes are stored there .. that will get you more specific info.
Not saying it is not the ECU, just possible to get code 19 CE with
bad injector, bad reg, vac leak, etc...
Dealer may be right , but BC you have owner access on that model, it would be easy enough to open the hood and see what the computer has stored on the diagnostics memory of the HFM-SFI module...
{Archieves-Led tool}

Replacing the ECU and finding that the problem is remedied can entail several drive/learning cycles [ which can take a week].. so , maybe they did that ??...many times CE lamp is thought to be fixed w/part change and sure enough, a week later..there she is again..

Both of those links are for the M119 4.2 liter engine.

I really wonder if the same issue applies to our engine...

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

Thanks Arther, Suginami. I will go to pin 8 and see why code 19 is coming up. I will also check the fuel pressure regulator and try to clean the EGR Tube and see what happens.

So far, my experiecne with Mercedes Benz dealerships has not been good. For my Check Engine Light problem, Dealer 1 thought Bad EGR Valve, Dealer 2 thought bad Mass flow sensor, then changed it to ECM. Dealer 3 thought wiring harness was bad.

This forum is extremely usefull and I have learned a lot. I have spent several hours doing research!!! Alldatadiy is another useful site where one can get detailed information about the systems. I still do not have the CD. Looking for paper copies of the repair manuals.

Thanks again and let me know if you have any other idea's.

Wow..

I was searching the forum for some help on another issue and came across this issue. I was originally involved on the Error #19 issue and tested the chip replacement. It did resolve my #19 issue, but it was specifically for an E420, not E320.

__________________
Willy

'94 E420 White

Mods
-------
Berg Werks Keyless Entry
Buzzer replaced with Chime
Dash Light Upgrade
Burlwood/Leather shift knob
Alpine CDA-9815 Head Unit
2002/2003 16" C Class 7-Spoke Wheels
Updated "Chip" to fix Code 19 problem

Replaced the ECM. Problem fixed.

__________________
Zafar
94 E320 58000 Miles