Jim F’s Code 19 Chip Update - PeachParts Mercedes-Benz Forum

AtlBenz · #1 09-02-2003, 08:56 PM

I just finished installing Jim F’s code 19 EPROM chip. I did this because my 1994 E420 was giving me a Check Engine light due to a code 19 error. Long story short, the chip works. It was a cinch for me to install, but I am a pretty handy guy and use with a lot of electronics at work along with doing all the mechanical stuff on my car. My car was equipped with the LED/SW combo, so resetting the check engine light was a cinch. The instructions he gives are clear and accurate. It took me 15, maybe 20 min to finish and I was taking extra care.

Just as a matter of clarity.

The "Required Tools" list that is included in the instructions talks about "Torx screwdrivers #50001 and #50003"…those numbers are not consistent with the standard method of Torx nomenclature. The Torx sizes needed are T10 and T15.

Also, a lot of care must be taken when removing the old chip and installing the new one. Pulling the old one too hard It took a bit more pressure than what I would have expected to seat the chip.

When removing the plastic guard that covers the factory chip, it is best to use the two small slots that are prefabricated into the cover. A small flat-head screwdriver levering away from the chip pops it off with almost no force.

Well I guess that’s it. Any questions? It really is that easy.

THANKS JIM

JimF · #2 09-02-2003, 10:44 PM

long list of DTC#19 success stories. Glad it worked!

Tnx for the feedback: will add a note about removing the old chip. The easist way is to wedge a small flat blade screwdriver under each end (in turn) and pry it up gently. After doing this a few times, alternating ends, the chip comes right out.

PS: just reviewed the instruction sheet and the "flat blade screwdriver" is there. OK. . . I'm happy.

wjm · #3 09-03-2003, 05:38 PM

That Jim is lifesaver!!

JimF · #4 09-05-2003, 02:17 AM

You are too!

Joseph_H · #5 09-13-2003, 07:15 PM

Jim, Willy,
My CE light came on again yesterday and it was code 19. The car drives fine and was able to reset it... it came on again today. I had the chip with code 19 fix installed for about a month or so since last time I had code 19 when this first happened, any ideas? only note i have here is that when compared the BIN file size of the chip with code 19 fix and my original chip both had identical file size.. any help from you guys will be great. thanks.

wjm · #6 09-14-2003, 01:11 AM

The bin files SHOULD be the same exact size. You sure the right chip went in?

Did you reset the adaptation on your vehicle? You may need to. Look at some previous posts, as I don't quite remember at the moment.

Joseph_H · #7 09-14-2003, 02:46 AM

reason i asked about the BIN file size because I saw in one of your posts you mentioned that the DTC19 fix BIN file was 18 Bytes larger than the old original one. If my memory servers correct that is...

And I did reset the adaptation as per your email instructions at the time.. something about holding the PB for 6-8 seconds after ensuring no error codes in the system and turn off ignition and wait for 30 second... any other ideas?

wjm · #8 09-14-2003, 10:17 AM

Quote:

reason i asked about the BIN file size because I saw in one of your posts you mentioned that the DTC19 fix BIN file was 18 Bytes larger than the old original one. If my memory servers correct that is...

Nope... I said (or at least I meant) that they were 18 bytes different.

Quote:

And I did reset the adaptation as per your email instructions at the time.. something about holding the PB for 6-8 seconds after ensuring no error codes in the system and turn off ignition and wait for 30 second... any other ideas?

I think there is a way to do it via shorting 2 of the 38 pins. Let's see if JimF remembers.

JimF · #9 09-14-2003, 11:33 AM

that you installed, I'm not sure what it is? If it were, then the new s/a limits could not be exceeded so quickly. Suggest you have the s/a read with a scanner that can read live data such as the AST Retreiver. That's the only way you will know what the present value of s/a is.

Also with my chip, there's no need to reset the s/a since the limits more than adequately bracket the old eprom's limits.

Another way, remove the chip and send it to me to check. I strongly suspect we will find that's it NOT the right chip. You can't tell if it's correct just by the size of the files since they are all the same size.

Joseph_H · #10 09-29-2003, 01:55 PM

Since I installed the chip with DTC19 fix and a month later code 19 reappeared, I went back and re-read old posts and found out that there is a way to set the adaptation back to mean by shorting pins 1 and 4 on the 38-pin diagnostic connector (I believe JimF had that information posted). I went back and resetted my adaptation about 2-3 weeks ago after i cleared code 19 and haven't seen 19 come back again. Prior to doing so, i was getting code 19 almost every other day after driving the car. So for some reason after installing the chip you may want to consider setting adaptation to mean value... this is just my experience and it had been 2-3 weeks and will report back if 19 comes back again as this will indicate possible problems with fuel line other than those related to the ECU chip.

mbdoc · #11 09-29-2003, 05:45 PM

Code 19 isn't always a computer programming problem. MANY times the air mass sensor is defective OR the fuel pressure regulator is at fault. IF you have a modified "chip" or ECU & code 19 still comes on you should think about the possibility of a failed component other the the computer.

Joseph_H · #12 09-30-2003, 01:24 AM

a "quick n easy" way to test air mass sensor or the fuel pressure regulator?
It happened a couple of times few weeks ago that the tachometer needle was dipping below the 500 rpm mark during traffic-light stop and dtc19 would come on the next time i start the car... but that hasn't happened after i resetted the adaptation as I described above... it beats me! Now everything looks normal and the car drives great. Needle sets at about 500 rpm during stop while in gear and about 550 when in neutral. I am diffenetly keeping an eye on it and will be looking for testing few components that may cause fuel delivery problems... Thanks in advance for any pointers..

mbdoc · #13 09-30-2003, 09:07 AM

Code 19 almost always means that the engine is running RICH. Of course the car is running good!! However the emissions emitted are out of range & long term can effect engine wear.

stevebfl · #14 09-30-2003, 10:04 AM

The whole story is viewed through the adaptation values. On HFM and LH they are lower and upper partial load adaptation. These are multiplicative adaptations, meaning the fuel trim calculation is increased or decreased by multiplying the the number times the original calculation.

There is also idle (CTP closed throttle position) adaptation which is additive.

A rich condition driving down the road will aquire a multiplicative correction that can often not be needed at idle. This is where the final correction is added on top of the multiplicative.

The analysis is to look at all three values and see which one has reached the limit. The original programming gave a multiplicative correction from .85 to 1.15. The new program goes .68 to 1.32. I don't know if they expanded the additive idle correction but the amount is 1ms if I recall.

One should check all three values.