
168 RENR9348-01
Troubleshooting Section
During an engine start sequence, the Starting Motor
Magnetic Switc
h (SMMS) is used by the Electronic
Control Module (ECM) to engage the starting motor.
Control input voltage for the SMMS is supplied by
the ECM. When t
he ECM supplies the signal to the
circuit, the SMMS is energized. This powers the
starting solenoid and the starting motor engages.
The SMMS is de-energized by the ECM when the
engine speed reaches the crank terminate speed.
The crank ter
minate speed is a system configuration
parameter that is originally set at the factory. Refer to
the parameter table that is found in Troubleshooting,
“System Con
figuration Parameters” for the current
setting of the parameter.
Circuit pro
tection for the SMMS is provided by a
circuit breaker that is located in the secondary circuit
that is between the +Battery and the input terminal
for the SMMS
.
g01208810
Illustration 9 9
Circuit schematic for the SMMS
Test Step 1. Inspect the Electrical
Connectors and the Wiring
A. Turn the battery disconnect switch to the OFF
position.