ELECTRICAL SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
CAT DATA LINK CIRCUIT TEST - CONTINUED
Connect MSD and ECM to another battery.
WARN I N G
Batteries give off flammable fumes which can explode. To avoid injury or death, do not strike match, cause
spark, or smoke in vicinity of battery.
CAU T I ON
DO NOT connect bypass harness to battery until 20-Amp inline fuse has been removed from +battery line.
If fuse is not removed before connection to battery, spark may result.
Connect battery wires from bypass harness to different battery.
If MSD is operating correctly, perform Electrical Power Supply Circuit Test in this work package.
If MSD is NOT operating correctly, perform these steps:
Replace engine ECM (WP 0053 00).
N OT E
ECM should be programmed with correct software. All parameters should be set to same value as suspect
Remove all jumpers and reconnect all connectors.
Recheck system for active diagnostic codes. Verify repair eliminates problem.
CHARGING SYSTEM TEST
Verify alternator B+ terminal nut is tight and verify wire has a good connection to B+ terminal (WP 0047 00).
Start the engine and set the throttle to at least 75 percent using throttle lock (TM 5-3805-290-10). Turn ON all electrical
accessories for all tests below. Allow the engine to run for at least three minutes before continuing to step 3. Table 4 will
assist in making calculations during this test.
3 minus 4 =
5 minus 6 =
Measure the voltage between the alternator B+ terminal and the alternator case ground.