Resetting DME

[B. Elliott]

1990 C4. Is there a way to completely reset the DME and clear all stored codes other than using a Bosch Hammer? I've worked on a ton of other domestic and foreign autos (mostly OBD1 and some OBD2) and there always seems to be a way to at least clear everything and start from scratch. I just re-soldered the joints within the clock to clear my seat belt/air bag trouble lights, but don't want to wait to have the dealership clear it. There just HAS to be a way to reset everything without using a Hammer (at least I hope).

[Bill Verburg]

Originally Posted by B. Elliott

1990 C4. Is there a way to completely reset the DME and clear all stored codes other than using a Bosch Hammer? I've worked on a ton of other domestic and foreign autos (mostly OBD1 and some OBD2) and there always seems to be a way to at least clear everything and start from scratch. I just re-soldered the joints within the clock to clear my seat belt/air bag trouble lights, but don't want to wait to have the dealership clear it. There just HAS to be a way to reset everything without using a Hammer (at least I hope).

Just disconnect the battery, non volatile RAM wasn't added until the 993

[sml]

Originally Posted by Bill Verburg

Just disconnect the battery, non volatile RAM wasn't added until the 993

this might clear the codes but just so that we are very clear ....

disconnecting battery is not the same as the hammer adaptation

would bet my life on it.

spent thousands trying to fix a dodgy idle dip on a 91 C4.

tried battery disconnection about 40 to 50 times.

eventually solved with hammer adaptation for free.

[Bill Verburg]

Originally Posted by sml

this might clear the codes but just so that we are very clear ....

disconnecting battery is not the same as the hammer adaptation

would bet my life on it.

spent thousands trying to fix a dodgy idle dip on a 91 C4.

tried battery disconnection about 40 to 50 times.

eventually solved with hammer adaptation for free.

The DME will self adapt the following
oxygen sensor
idle speed
idle speed CO


self adaption takes place during the 10min after a restart after the battery disconnect

[Lorenfb]

Bill is correct on both issues:
1. battery disconnection will fully reset/clear all codes,
2. the DME ECM with self-adapt after the engine runs
for a few minutes.

[sml]

i know that both bill and lorenfb are some of the most knowledgeable and helpful guys around but .....

there is no possible way that the self adaptation is the same as the hammer adaptation.

my idle was completely different after a hammer adaptation after trying 40-50 battery disconnects.

there is also 5 or 6 other C4 owners on the rennlist forums that agree.

[panicosc]

I know this is a very old discussion but my question is very related.

The fuse No 35 which is taged DME power if removed can it reset the DME ?
The other im in doubt is after the DME reset the 10 minute drive has to be fast and spirited or smooth?