I agree with regards to the ETA.

Perhaps at some point this summer I will take it out and rewire it.

__________________
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
609 Certified

Those codes are classic pointing to a "going-bad" . . or . . "gone" ETA.

However, if you haven't replaced the S16/3 . . . it's a cheap fix, so you should consider changing it first.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

Thanks for the replies.
I tend to believe the ETA is not bad yet.
JimF, from your website:
"One key point: with the OLD ETA, I could NOT reset the codes in the EA/CC/ISC or ASR: i.e., after using an AST scanner to reset the codes and recycle ignition key, the codes would immediately reappear without starting the car. According to one of my MB manuals, that indicates that the ETA is bad. "

I am able to reset the codes every other week, although the possibility exists that intermittent wiring problems in the ETA causes the LM-ASR.

"A KEY troubleshooting fact: When reading DTCs from the EA/CC/ISC module hooked to a properly functioning ETA, a mechanical sound will be heard as the motor turns and 'resets' it's position. It can clearly be heard. Needless to say, that sound was missing from my car with the old ETA. Another 'clue' that points to the ETA assy."

There is a (whirring/humming) mechanical sound coming from the ETA whenever KOEO (checking for codes). That "sort of" tells me the ETA is functioning properly.

Since the Limp Mode is so sporadic/intermittent (once-twice every other week), I will not take action until it worsens. And when it does, I will first change the NSS.
It is a "trip" to drive in limp mode, the car had no problems maintaining 80MPH on the highway, but I had to press the gas pedal far down. And cruise control is unavailable.

__________________
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
609 Certified

Good job on rebuilding the harness. Did yo run new wire all the way to the computer connector or did you splic in near the battery? If you spliced in you want to keep an eye on the remaining old wiring as you may get a short inside the connector (ask me how I know)

You can try rewiring the ETA. I did and got another 6 months before the internal pots died and I had to buy a replacement. If you want a recommendation for a source for a rebuilt ETA pm me.

Greg

And it could very well be the NSS . . and not the ETA . . . esp since all other symptoms are "soft".

Just make sure that you get it into 4th gear . . that, as you found out, it takes a little practice to get it to shift gears. I wouldn't want to drive it that way.

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page

I did splices behind the firewall (about 6 inches from the connector). The wire insulation was good and soft at that point. The battery for the E420 is in the trunk.

I will PM you for the info, although I live relatively close to Beckman technologies in Durham.

JimF, indeed it requires practice, got to release the gas pedal just enough to shift, and then feather the gas to keep the speed without downshifting.

__________________
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
609 Certified

I did the harness on a 1993 300E with the battery in the engine bay. My wiring looked good from the computer connection to just after it exited the battery compartment.

A few months after rewiring, I developed a misfire that the codes kept telling me was a bad coil pack even though all three were brand new. I finally found the problem by ringing out the primary side of the the coils and finding that cyl 2 was shorted. The short was actually inside the epoxy potting compound inside the connector housing.

The good news is that the plastic housing is available from MB for under $20.00. the bad news is that the only way to get the 44 pin connector plate is to buy a new harness. I wound up cutting the old housing off and rebuilding the harness a second time from the computer connector to each termination. Surprisingly all of the coaxial wires had a silicone insulation that showed absolutely no degradation, so I was able to simply slip them through the new connector housing and resolder them in their original location.

Greg

Just a last update, given the car has been on the road for a while.

Found the root cause of the occasional ASR with Limp Mode. It was not the NSS or ETA.

The rear passenger side tire loses air slowly, I had not made the connection until yesterday.

Limp Mode would not go away with a restart. Checked tire pressures and it was 25 psi, the other was 35psi. Filled it up and ASR went away.

Drained the air down to 25 psi, ASR with limp mode came back right on take off, filled tire up, it went away.

I did it 3-4 times to make sure (repeatability). Another lesson learned.

By the way, got a new AC compressor from Duracool, after doing the necessary steps (vacuumm, check pressures, etc..). Vent temps are 39.1 - 41.2 on the highway on a 94 degree day with 60% humidity. Can't complain.

Also changed the water pump while I was there (do not ask me what it took to remove the harmonic balancer, I rather forget - PITA)

Additionally, installed the "cool harness" (soldered a 1150 ohms, 1% metal film resistor). Fans come on like clock work around 94-95, and shut off at 87. Thanks JimF, I am a regular visitor of your website (always looking for updates)

I will bring the car to a shop to replace the O2 sensor, I just cannot do it.
That will get rid of the check engine light and the codes (22 on pin 4 and 12 on pin 19).

__________________
1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
609 Certified

Glad you like the Fan Mod . . . does work well.

I just replaced my rear headrest motor assy. It was "clicking" so the gear was stripped. More details on in Menu#34

__________________
Regards . . . . JimF
-------------------
'94 S500 Cpe

Visit my Mercedes Web Page