ELECTRICAL SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
ENGINE TEMPERATURE SENSORS OPEN OR SHORT CIRCUIT TEST - CONTINUED
Check ECM operation by creating open and short circuits at ECM connector.
Turn engine start switch to OFF position (TM 5-
Disconnect J1/P1 ECM connector (WP 0053 00).
Disconnect connector for ECM harness. Inspect
both halves of connector for corrosion or mois-
ture. Refer to Electrical Connectors Inspection
(WP 0022 00).
Turn engine start switch to ON position (TM 5-
3805-290-10). Use MSD to monitor Active
Diagnostic Code screen. Wait at least 15 seconds
for activation of code.
Expected Results. Open circuit diagnostic code should be active for suspect sensor.
N OT E
When engine harness is disconnected, all open circuit diagnostic codes for pressure sensors will be active.
This is normal. Disregard diagnostic codes for pressure sensors.
Use jumper wire 6 in. (15 cm) long with correct terminals on both ends of wire.
Install jumper on back of engine harness connector. Install one end of jumper at sensor signal on bypass harness.
Install other end of jumper at terminal 34 common connection for bypass harness. Wait at least 15 seconds for acti-
vation of short circuit diagnostic code. Monitor Active Diagnostic Code screen on MSD before and after installing
Expected Results. Short circuit diagnostic code is active when jumper is installed. Open circuit diagnostic code is
active when jumper is removed.
If results are OK, use MSD to clear logged diagnostic codes. Proceed to step 7.
If results are NOT OK, ECM does not operate correctly.
(a) Remove all jumpers and replace all connectors.
(b) Replace engine ECM (WP 0053 00).
(c) Verify repair eliminates problem.