Unplug the ISCM position sensor harness connector from the sensor. Turn
the ignition ON, and measure the power supply voltage from ISCM
harness terminals 2 and 6. If the voltage is not 4.8–5.2 volts, repair
the harness from ISCM terminals 2 and 6 to ECM terminals 13 and 23.
Turn the ignition switch to OFF and check for continuity
from ISCM harness terminal 3 to ground. If no continuity is detected, repair
the harness from ISCM terminal 3 to ECM terminals 14 and 24.
Unplug the ECM harness from the ECM, and check for an open-circuit (or short-circuit)
between the ECM and the ISCM position sensor. Check from ISCM terminal 5 to
ECM terminal 17, if a short or open-circuit is found, repair the harness.
If no short or open-circuit is found, the harness is good.
Fig. 1: The ISCM position sensor harness testing
procedure — 2.4L engines
