slant911

Well this has been a long process of testing to see if it would work on my 90' C4.

Horst has been supporting me all the way and provided me the procedure and codes today. I tried it and it does NOT work. I followed the procedure as outlined. Held the throttle all the way down turned key to on and waited another 10 seconds (only supposed to be 3, figured I'd give it the best possibility) and the check engine light just stays lit solid. No codes.

Thanks anyway. Kinda stinks that it didn't work.

Adrian

Dear Slant,
I think we canconclude that your DME is the wrong part number and does not contain the correct software. However before losing all hope make sure your "wide open throttle" microswitch is working. This must be closed to activate the system. Pedal full to the floor. It would not be the first time that the arm on the throttle body does not reach this microswitch,
Ciao,
Adrian
911C4

horst

The other factor which may be a consideration is that my car is a California option car, (CO3 code) I think as we have been thrashing this out that MAY be a consideration. I wonder if Melissa has tried this? I believe she has a CO3 as well. The only other thing I can think of is that I had my brain updated by Porsche, a freebie, because I was chasing a running problem at the time.

Adrian

Dear Horst,
Option C03 only made a short term difference in model year 1991. CO3s got the right part number DME and CO2s did not. However this was overcome very quickly. A matter of a few months and all 1991 models were active.
You know that for your 89 C4 you wired or the PO wired up the light and you had the DME updated. In 1990 the wires were installed but you still need to install the lamp and use the correct part number DME or have your existing DME updated.
I think you were the last to ever get this done for free,
Ciao,
Adrian
911C4

slant911

Just a reminder to you guys/gals. My vehicle is a 90' C4 (CA) with a 964XXXXXX DME not a 911XXXXX DME. I will check on the microswitch, however, I figured that was the trigger mechanism for the test so I already sort of looked at that. The only thing I didn't do is have someone else push the throttle down while I check to make sure the switch makes contact. The throttle body when moved by hand from the rear definitely makes contact.

I'm disappointed that this experiment apparently did not work

horst

My car is also a CA spec 90 C-4. From what I see as a result of your efforts, slant, is that the only difference is that I have been able to get Porsche to update my DME

slant911

Horst,

That does "seem" to be the only logical difference. I'm not sure I really want to go to the trouble to get mine updated so that it will spit out some codes. Even if it were free (which I doubt) the hassle seems too much. And, I'm finally getting to the point that my car is running good. I don't want to disturb anything (especially the master brain) and run the risk of screwing things up. Maybe somtime in the future if I do have a problem with the DME r something I will get it updated. For now the check engine light comes on when I turn the key on. Likely will never come on otherwise.

horst

It was free for me, but I agree with your logic.

slant911

Here is something odd. I found today that the check engine light DOES work. With the O2 sensor disconnected the check engine light came on after driving for about 5 minutes. It still will not spit out any codes, but, does apparently report engine troubles. I came back home and reconnected the O2 sensor and the light went away.

GO FIGURE...

Adrian

Dear Slant,
This does not surprise me. You said you have a 964 part number DME. These had the "Check Engine Light Function" which was originally only required under Californian law to work for the O2 sensor. However this was updated very quickly and the Bosch 9268 tester (not the 9288 tester) software was installed to give the flashing codes. You are halfway there but still need a new DME to get the flashing codes or make sure the wide open throttle microswitch is actually working correctly as already stated.
Ciao,
Adrian
911C4

slant911

I have checked thatthe throttle is all the way down and pushing the high switch. No codes. Oh well. I'll leave the light in there so I'll know when the O2 sensor is bad next time (10 years from now).

Thanks all.

Adrian

Dear Slant,
I know you have posted it before but would you be so kind as to post your DME part number again. No stress and please do not disassemble your 964 to find it. If I get time I will search back in the messages,
Ciao,
Adrian
911C4

horst

I feel we may be beating a dead horse (Horst) here? But, Slant, have you thrown any buisiness to your Porsche dealer, whereby they might have good thoughts about you? Have you asked, innocently, if the program to update early DME's can still be used. What can they tell you "get lost"? Nothing to lose in asking. Give the service writer his belated Christmas present, a Box of Ansbach Uralt schnapps bohne, or a bottle of Jack Daniels? ( I am not above bribery)

horst

supposedly, the thing runs better,too. I think mine does, but then I had other problems at that time.

slant911

Adrian,

My DME part number is 964 618 124 00.

Horst,

All I've purchased from the local dealer is (2) instrument lights (one for check engine, one for spare), a suspect oil cap, and a DME Relay. Don't think they are going to help me out much, but, I'll give it a shot. Again though, as I stated before. Everything is running great right now. Don't want to rock the boat, so, I'll probably just wait on reprogramming the DME until someday when it needs to be out for whatever reason.