I am spending my layabout covids vax rxn day learning about the 722.9.
There is a surprising amount of info available. I found this workshop
training doc
https://at-manuals.com/wp-content/uploads/2016/manuals/722.9%20Manual.pdf
Cars • TransmissionNew Automatic Transmission 722.9NAG2
(7-Speed)Diagnosis, RepairAdvanced Training
One section (p. 30) says that the TCM talks to all these systems. This
suggests that there is some sort of comms going on with the BAS which I
guess is tied into the SBC. The car is throwing a fault in the SBC
(accumulator is not providing the necessary pressure) and I wonder if
that is somehow causing this limp mode fault that says the TCM is not
working right. That might not be as the limp mode is intermittent, that
fault is constant.
05/04Cars Transmission New Automatic Transmission 722.9 NAG2 (7-Speed)
Diagnosis, Repair Advanced TrainingSystem Function and Networking
29Data exchange over CAN-CExchange of data takes place over the engine
compartment CAN (CAN-C) with the following control units:
•Instrument cluster (A1)
•ME control unit (N3)
•Electronic selector lever module control unit (N15/5)
•ESP control unit, PML and BAS (N47-5)
•DTR control module (N63/1)•EIS control unit (N73
There is also a 4 (or 5)-pin connector/plug that connects to some
controllers and fuse+relay. Some writeups I found says these can also
leak fluid through some o-rings and goober up the connector like on the
722.6 although it is a slightly different setup. It apparently can
cause the limp mode. That seems like the first place to start so I will
have to get the car up soon and check it out. Replacing the o-rings
involves dropping the valve body and conductor plate similar to the
722.6. Refilling the fluid is some involved process as there is no fill
tube and dipstick so it has to pumped in through the bottom with a
special tool.
--
--FT
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