slant911

Sorry if this has been covered before, but I couldn't find anything on it.

Background story.....Had my battery out about a month ago and after reinstalling I got in and took off. I never pput two and two together until reading the attached service manual info, but I had a wierd kind of throttle studder at very low RPM. Wasn't real noticeable, but definitely there. I didn't figure it had anything at all to do with battery disconnection so I cleaned the MAF, new air filter, etc... and figured I needed new spark plugs until I read the following in the DME Manual:

DME 7.8
DME 7.8
PEIN2DME78
0
Printed in Germany – 14, 2003
Note on adaptation
The DME control module must perform a learning and adaptation
routine for the throttle adjustment unit if:
♦The power supply to the DME control module is interrupted
♦The DME control module plugs are disconnected
♦A new DME control module is installed
♦The throttle adjustment unit is replaced
♦The DME is programmed.
To do this:
1. Switch the ignition on for 1 minute without starting the engine.
Do not actuate the accelerator pedal (for instance, make sure
that there is not a carpet pressing on the pedal).
2. Switch off ignition for at least 10 seconds.
The following conditions must also be observed, otherwise learning
is not possible:
♦Vehicle is stationary
♦Battery positive voltage between 10 V and 16 V
♦Engine temperature between 5 °C and 100 °C
♦Intake air temperature between 10 °C and 100 °C


I disconnected the battery again last night and followed the above procedure and BAM the throttle is smooth as glass.

Thought this might help others.

porschedude996TT

Good info...

I bet the guy down at Sears putting the new "Die-Hard" Battery in doesn't know this, nor the owner...

srf506

Nope they don't, its just setting the throttle to "true zero" in the software so it has the right Throttle position calibration in the Fuel Injection map. We used to do it manually in the MOTECS on Alex Job's old 911's in IMSA. Plug in the PC select the TPS calibration mode on the menu have someone push the pedal to the floor, set the value to 100%, have him let it off and set zero. Then have him repeat it to check that it took or the pedal was really all the way down and up. If you did anything to change the throttle linkage or the throttle stops you had to remember to reset this. Now it sounds like the computer does it for you sitting still.

autobonrun

I stumbled on this thread while searching for reasons my TTS was hesitating even after a service and spark plug change. It never happened under acceleration, just when I tried to hold a constant speed with my foot. What made me start searching for throttle problems is it did not do this when I set cruise control.

I tried the 60 second reset described above (about a week ago) and the hesitation is totally gone. I always doubt fixes that are free but this one worked. I've taken three drives, exact same route each time, and the section of road where I could detect the hesitation is now clear sailing.

I was a little apprehensive after reading the reasons this reset is required, since I had not done any of them, but perhaps the PO did something that called for a reset that was never done. Seems like just changing a battery calls for the throttle reset being done.

This is absolutely the cheapest fix I've ever had work. I'll watch it for several more months to see if it is permanent.

Macster

The E-GAS reset/recalibration can sometimes help cure some hesitation issues. If it hasn't been done in a while or the battery was replaced recently the operation doesn't cost anything but a minute and a few seconds time.

I do this for both cars every so often. A good time for me is when I get the car back from servicing -- at least every 5K mile oil/filter servicing -- or when I replace, or have replaced, a battery.

NO need to go overboard and do this any oftener. In fact every 5K miles might be overdoing it but AFAIK there is no harm in doing this.

James88

Well I have to thank you for stumbling across this and posting, as I too replaced my battery and developed the hesitation at low RPM's particularly when cold. I have just done this and will see in the morning if it has fixed it.

"02996ttx50

this procedure must also be followed when changing the MAF. many people forget

911 Rod

I hope this is in a sticky somewhere!
Does this apply to cars before the 2003 bulletin?

Macster

If you are talking about the E-Gas calibration, AFAIK, it applies to any car with E-Gas. The E-Gas calibration instructions are in the owner manual of my 2002 Boxster.

Chris996

Will do! Nice!

jeffreysurfs

Solved my accelerator"oddness" too....getting used to the super light hydraulics of the 02 996tt clutch i just purchased, i was wondering why at times it felt my 35+ years of manual clutch driving skills went out the window...much smoother now

LuigiPetrone

do you need to disconnect and reconnect the battery before following this procedure or can i just go ahead and follow the steps?

kmagnuss

Just follow the steps.