Re: Après le problème à chaud le problème à froid !
Publié : 16 janv. 2021, 18:15
oui il y a une différence entre le knock et l'adaptation, dans l'absolu, mais l'adaptation vient faire un règlage affiné qui n'a que très peu d'impact sur le bon fonctionnement ou non du système, l'adaptation joue essentiellement sur le CO, et 90% des améliorations quand on a une auto qui merdoie vient du knock. les infos sont très peu documentée, mais Lorenb sur le Rennlist avait fait une synthèse très bien foutue d'une note du PCA
Idle Adaptation
"What exactly is a 'system adaptation', and how is this different from a
battery disconnect reset of the DME?"
The 964 DME ECM has two adaptations:
1. Idle Adaptation -
On the earlier 3.2 DME system the idle was set by an external jumper
(caused open-loop idle) & then the idle screw was set to "center"
the idle RPM. On the 964, the Hammer causes the DME to go open-loop
and then causes the DME to "step" to the center for 880 RPMs. This
results in the closed-loop idle being "centered" for full
regulation.
2. CO adaptation -
The 964 DME ECM goes thru a CO adaptation whereby it runs open-loop
without the O2 sensor to "center" the CO setting to allow for small
variable changes, e.g. air leaks, fuel pressure, so in the
closed-loop mode the O2 system has optimal range (similar to TRA in
OBDII).
Both of the adaptation values are "lost" if the constant battery
voltage (pin 18) is removed. #1 above requires use of the Hammer. #2
occurs at initial running after battery voltage "loss".
"What happens with the idle in the case of a battery disconnect and no
hammer adaptation?"
The closed-loop still maintains the target idle of 880 RPMs but it's not
optimized for load changes, e.g. the A.C. compressor, the fans, the
lights, and the adapted CO setting.
Idle Adaptation
"What exactly is a 'system adaptation', and how is this different from a
battery disconnect reset of the DME?"
The 964 DME ECM has two adaptations:
1. Idle Adaptation -
On the earlier 3.2 DME system the idle was set by an external jumper
(caused open-loop idle) & then the idle screw was set to "center"
the idle RPM. On the 964, the Hammer causes the DME to go open-loop
and then causes the DME to "step" to the center for 880 RPMs. This
results in the closed-loop idle being "centered" for full
regulation.
2. CO adaptation -
The 964 DME ECM goes thru a CO adaptation whereby it runs open-loop
without the O2 sensor to "center" the CO setting to allow for small
variable changes, e.g. air leaks, fuel pressure, so in the
closed-loop mode the O2 system has optimal range (similar to TRA in
OBDII).
Both of the adaptation values are "lost" if the constant battery
voltage (pin 18) is removed. #1 above requires use of the Hammer. #2
occurs at initial running after battery voltage "loss".
"What happens with the idle in the case of a battery disconnect and no
hammer adaptation?"
The closed-loop still maintains the target idle of 880 RPMs but it's not
optimized for load changes, e.g. the A.C. compressor, the fans, the
lights, and the adapted CO setting.
pas optimisé pour "load change" ... 
merci ! je vais pas éplucher tous les modèles alors que tu as déjà le bon 
... ça a sûrement évolué pas mal depuis