Service Hints

Multiplex Communication System

I19 (A), I20 (B), I21(C) INSTRUMENT ECU
(A) 21 - GROUND : Approx. 12 volts with ignition SW ACC or ON position
(B) 2 GROUND : Approx. 12 volts with stop light SW at on
(C) 1 - GROUND : Always approx. 12 volts
(C) 2 - GROUND : Approx. 12 volts with ignition SW at ON or ST position

S5 STOP LIGHT SW
2 - 1 : Closed with brake pedal depressed