Note: the '7747 and '7783 at least use the same method of preventing overload to the A/D circuits--a 10k resistor seen in the following images ("103").
Peter of DIY_EFI indicated the following which is verified
by the image below:
----------------------------- +5
| |
/ |
\ \
/ 3.6k \ software controlled
\ \ switch
/ o \
\ |
| | 10k
|------------------------/\/\/\/\---o to A/D, etc.
|
/
\
/
\ 348
/
\
|
|
o terminal on ecm

C11 (MAT) looks to be like
----------------------------- +5
/
\
/
\ 2.5k
/
\
| 10k
|-----/\/\/\/\--o A/D
|
|
|
|
|
o terminal on ecm
