I need to replace the HFM-SFI Control Module on my 1994 E320 with 76K miles.

MB Dealer quoted $2200.00.

I would like to repair the unit or buy a used one.

Any suggestions and sources where the ECM can be repaired or purchased used.

According to a TSB, "starting in Jan 1994 and from March 1994, the automatic recognition feature was turned off, so the HTT Tool has to be used for coding the unit. Is there a work around this?

This will solve the HFM code 13 or HTT code 035 Adaptation at limit and Emissions codes 3, 4 and 19.

The car drives fine, but I do not like to see the Check Engine light on. I have had this issue for sometime, but have decided to finally address it.

Wiring Harness, Head Gasket, ACC Control Unit, OVP, Fuel Pump Relay, Plug to coil Connectors, ACC aspirator motor, ACC Interior Temp Sensor, Aux Fans, EGR Valve, MAS etc. have all been changed. 02 sensors maybe next. Is that an easy DIY?

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Zafar
94 E320 58000 Miles

All you actually need is the 36k file that sits on the prom in the new controller.

You can get a reprogrammed one here: http://www.beckmanntechnologies.com/products.html

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Thanks for the info.

At MB the ECM is $1860.00
At Beckman $1209.00
At car-part from $85-


I ordered one from car-part.com for $200.00 from a 95 E320, has the same part number as mine 016 545 5732. It appear that the "DAS" system was not implemented till 1996. As long as the other car had the same features like the ASR system, version coding maybe not be needed.

Plan is to install the new unit, reset the long term adaptation curve and start the engine!

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Zafar
94 E320 58000 Miles

There are only a few variants on that year car and one of them will be spelled out.

You have missed the point though. If you are trying to solve an adaptation problem with a control unit you haven't done a thing by buying the same number. It will have the same software as yours. The reason for changing computers is to get new software that allows + or - 32% fuel correction rather than the + or - 15% that came with the original controllers.

Did you talk to the people at Beckman. The controller price you saw is for a repaired (rebuilt) unit with the new software. It might be possible to deal with your unit from a different standpoint.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

The MB Dealership actually came up with a new computer as the solution.

They started with replacing the O2 sensor, that did not affect the numbers, then the MAS, OVP and finally the ECM.

After replacing the ECM, according to the service advisor "everything was working like it should".

I believe that due to the bad wiring harness, some part of the ECM is defective and is stuck in a fail safe mode.

Other items like vaccum leaks, fuel pressure, sov etc. are all within spec. The engine is in like new conditon.

The above diagnosis was done after the 60K service, after replacing the plugs, filters, fluids etc.

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Zafar
94 E320 58000 Miles

If your car runs fine but sets adaptation codes thinking that the wiring did something to the controller is wishfull thinking. This is a known problem and the dealers answer is straight from MB. There is even a service bulletin on the v8 models.

Hard to say from here but the reason for changing controllers on early LH and HFM cars with adaptation codes is the software. An old unit with the same number will have thensame software (unless someone has reprogrammed it). There are guys out there selling just the chip.

If the used controller fixes it nevermind, when it does not, check around for a chip built on the lastest MB software and sell me the one you don't want.

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Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

Replaced the ECM. Drove for some time. Checked codes. Getting DM code 1, Pin 8 code 1.

Pin 14 code 7. Was getting this code with the old ECM as well.

Looks like this fixed the problem with the check engine light. Will check the codes again after a few days.

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Zafar
94 E320 58000 Miles

Code 7 on 14 can be CTP recognition fault.... make sure there is a little slack in the cable at idle and that the cable is not sticking....