Engine System, Diesel
93
Service Manual – SC8000
Connector Callout – Relay PCB
Pin#
Color
Type
Voltage
Pin Description and Function
J7-1
VIO/GRA
Input
B+
Module relays load power supply
J7-2
BLU/PINK
Output
B+
Engine ECU starter relay command
J7-3
WHT/BRN
Input
0V Floats
Engine start inhibit signal *
J7-4
BLK
Input
B-
Module relays coil ground supply
J7-5
PINK
Output
B+
Engine ECU ignition run relay command
J7-6
VIO/BRN
Input
B+
Module starter relay Bat +coil signal
J7-7
YEL/WHT
Input
0V Floats
Engine run inhibit signal **
J7-8
ORN/GRN
Input
B+
Module ignition relay Bat+ coil signal
* Note:
The normal condition for the start inhibit is in its non-inhibited state. A float voltage of
approximately 8V (when referenced to B-) is measured when the key is in the start position.
When inhibited, the signal is pulled to ground, will read 0V and will prevent the engine
from cranking. This prevents the starter relay from being energized.
** Note:
The normal condition for the run inhibit is its non-inhibited state. A float voltage of
approximately 10V (when referenced to B-) is measured when the key is in the start/run
and run positions. When inhibited, the signal is pulled to ground, will read 0V and will
prevent the engine ECU from receiving its needed input switch command. This prevents
the ignition system from firing, and if the engine is running will cause it to shut down.
Special Tools
Cooling System Tool
