Brian McL

I have a W210...97 E320...that we can't get to start. Here is a little history. Car would misfire when hard acceleration was attempted. DTC P0170. Tried to zero the adaptions by using the LED tool proceedure described elsewhere on this forum (PIN 1 and PIN 2 then PIN 4 ignition on then off then on etc etc.) anyway, now the car won't start. Got lottsa fuel pressure and ignition. Starter works fine. I have no fuel being injected....so the computer seems to have shut down the injectors. Any ideas? I know the computer will stop the fuel under certain conditions...so how do we reverse it? Or did I blow the fuel control computer trying to change the adaption. Re-checked the OBD II DTC and there are no codes ( I cleared them all just before this happened) so I'm hoping the computer is OK.

ohlord

are you?
you used the old obd1 method on an obd2 car..
you may have fried something..
disconnect the battery(key out)step on the brakes for 30 seconds
rehook up neg terminal.
that may reset the ecu
if not you toasted it.
ohlord
fuel trim code gone?
have you checked the fuel pump ?

Brian McL

Geez.....Are you joking about the brake thing??. Seems a little weird. I'll try it...just seems strange. Is there anyway of knowing which computer got cooked? I assume it would be the Fuel injector control module N3/7. Silver box second in from the back ? I think all the ECU's are in that one box. N3/7 and N3/10. I already got a line on one for $150. Why does this car have the 38 pin diagnostic plug? Thanks for the reply....MUCH appreciated.
Pump is OK...I got pressure at the rail. The P0170 is gone but once I get the car going I expect it will return....it always has in the past after a day or so. This new hesitation / misfire on acceleration is what started all this excitment. Thought I would "fix" the adaption. Any guess why it has started acting up on acceleration in city driving....always had a weird hesitation on passing at hiway speed/merging. Thought the kickdown wasn't acting right or the vacuum was wrong on the A/T. Maybe it was the ECU reducing RPM 'cause of the lean mixture....hence the P0170.....I dunno.....( I hate this car, but don't tell anyone.. miss the W124...ALOT)

ohlord

under the hood is for the dealer.
clear the code with the hhs,run a can of seafoam injector cleaner through the gas.Sort out the little issues and you will change your mind about the w210 they are lovely machines when well sorted.
Could be an o2 sensor, dirty maf diy on benzworld.org w210
if the reset and code clearing and seafoam don't clear it up then get it on a scope that reads real time values to check o2 sensors and injector values.
it may be cheaper to fix than you think

Brian McL

OK...thanks. So to recap the reset.
Neg. off at battery
Hold brake for 30 secs.
Neg battery on battery.
....right ?????
If that doesn't work then assume the ECU is toast???
Do I need to re-teach it all the other stuff like windows, radio ABS etc ????

ohlord

might not be toast,but something happened if it ran and now wont.
sync process is in the manual.code should be in the radio book if not dealer has it.

Brian McL

Could there be any other reason why the injectors aren't working? Is there a seperate injector power supply relay for this car? M104 engine.
Strangley, when I removed the pressure tester some fuel got into the air intake and when I once agian tried to start it did fire....just for second...from the fuel that sprayed into the intake....so the injector circuit is definitely the culprit. I have the computer out and and apart (just wanted to see if the board had any obvious scorch marks...it didn't...no surprise, but I had to look anyway ) Will put it in tomorrow and do the re-set......here's hope'n
PS what OBD reader are you using?

ohlord

scanner from harbor freight tools #94169 39bucks online or if you have one near by they will price match the online price.Handy unit works,bullet proof,reads,clears,i/m monitos,obd2 codes.
ohlord
no more fuel in the intake you will ruin the maf.

Brian McL

Yeah....the fuel is going in at the throttle body....the MAF is clear of it.

Brian McL

...well, that didn't work to re-set the ecu. So I guess it's toast. No codes on the HHT...nothing. Next question is which one is toast.....

ohlord

injectors working?Have you got spark?Those 104's were not as dependent on the electronics as much as the 112 they did have those harness problems.
Check everything all wires all vac lines,cam position sensor if it is gone the ecu won't have the proper signal to tell the fuel system to inject fuel.
alldatadiy will have the fuse and relay info.
Try to not throw parts at it other then the checks above and maybe the cam sensor,it may be cheaper to get it on the star machine and find out what went south.

Brian McL

Everything worked, with the exception of the misfire on acceleration, prior to me trying to zero the adaption on the 38 PIN plug. While I was setting that up I did short the #1 and #2 pin with a small spark but my LED tester has a fuse in it and that didn't blow. Plus, I can't be sure that I was in #4 at the time....but I might have been...............if so, could that have fried the ECU do you think??
The ignition spark is good, like I said the car will fire if I get a small amount of fuel in the throttle body...the harness isn't as much of an issue with the W210, but it looks OK...no crispy wires or weird codes etc. I'll look at the cam sensor. How do you check it though, and wouldn't the HHT show a PXXXX code if it was defective? I was thinking of buying a scanner like the OTC or Matco....this maybe the modivation I need. But it is a real head scratcher. Anyway, a local parts yard has a computer for $100. Wish I knew someone with a W210 I could play swap the parts with. Now......if it was a W124 I would have no problem...

ohlord

but even that might not show the relay or system.It is a great real time scanner but the money spent to use it the few times the average diy'r needs it might make more sense to go to a good indie with the star machine and get the diagnostics and then do the r/r yourself.cam sensor---still could be
Crank sensor if shot would also leave the ecu clueless as to how to manage the fuel.Wish I could be of more help on this oneNo more poking things in where they don't belong,okay?

Brian McL

...that's been my problem all my life...sticking things were they shouldn't be.... I've taken outthe OVP relay set and that all looks OK. Next I will do a check on the crank position sensor and the cam sensor........then I will get the ECU. Running out of options. Thanks for the hand holding.......nice to feel you're not alone when the ship is sinking.... (did I mention I HATE this car ?? )

124-Fan

1997 E320 w210..
Check the fuses in the car. Thorougly. They´re positioned in the left side of the dashboard under a removable plastic cover and also in the engine compartment where the 38 pin plug is. There is also a few of them under the rear seat to the right.

- Your air flow sensor might also be bad. Sounds slightly that way... and the misfire you described could also be nothing more than bad plugs.

Cheers,

Brian McL

Yeah...I found most of the fuses, at least I thought I did. I'll look under the dash. I wonder if they put any inside the headliner? They're all over the place. I REALLY would like to meet the group that designed this car

ohlord

under rear seat,little door to the left of the headlight switch,relays in box up by firewall and more fuses.injector relay you might call a dealer and ask for the number and track it down.
tell her you love her,she will understand your frustration
ohlord
fuse list on benzworld.org w210 tips section or maybe diy section

Brian McL

does this car have an injector relay? The only relays I could find are infront of the computer stack on the pas. side. No relays in behind the fuses on the DS...just looks like there should. In fact there is a lot of space and a couple of connectors. Maybe in the centre armrest in the rear

ohlord

never shorted out my engine bay portso I am not sure .Try the K-40 relay that in most benz incorporates the fuel injection relay.A tap with the back end of a screw drive ala how you whack a duovalve may free it up.
best pic i could find
http://www.benzworld.org/forums/r170...ssociated.html
ohlord
gotta be something,it always is

Brian McL

The K40 is the one hanging off the front of the computer stack. Already had that apart. There are all fine. I'm really leaning toward the ECU. There really isn't a whole lot that will shut down the fuel injection system. I read something about the "DAS" (Driver Auth. Sys) shutting it down. Part of the central locking system????but I can't find a reference to it anywhere. But it only works above 1200 rpm so it must be part of the limp home mode. Gotta be the computer. Will the SnapOn MT2500 give any more insight? A friend has one to sell......but I will need the MB "key"....whatever that is. He likes it.

ohlord

machine time

Brian McL

hmmmm......I just don't like giving in just yet ( or parting with my money). It's all a big game..."und vee vill vin"....

ohlord

when I first read hot rods to hell in the 60's across the back of the Corvette in pinstriping was the Latin phrase "Aut vinceri Aut mori"
so I know what you mean
ohlord

Brian McL

....what do you know about the DAS ..Drive Authorization System. ? I think I may have tripped it. Do you know how to reset it....without taking it to Mercedes so they can use their HHT and unlock it in 1 minute...for $75. AND it appears as though I can't just replace the ECU I also need to replace the RCL module (Remote Control Lock)...'cause they talk to each other, in bits and bites now doubt just like the dealer is going to try and take a bite out me to "unlock" my car I'll bet. Remember the radios in the early W124 300E's.....every time you replace or disconnected the battery you had to take the car back to the dealer to unlock the radio...for a small fee of course.

Brian McL

...and so we shall........