Mercury MerCruiser MIE 7.4L MPI - Page 694

GENERAL SYSTEM DIAGNOSTICS
SERVICE MANUAL NUMBER 23
90-861326--1 MARCH 1999 Page 5E-101
Discrete Input Circuit Check - Non-Scan 7.4L MPI Only (4 of 5)
TESTING CIRCUITS FOR SHORT-TO-GROUND (–)
STEP
ACTION VALUE YES NO
PROCEED TO
1
1. Disconnect PUR wire from oil pressure
switch.
2. Disconnect TAN/WHT wire from gear
lube monitor.
3. Disconnect BLU/TAN wire from transmis-
sion temperature switch (if equipped).
4. Key “ON”, engine “OFF”.
Does audio warning buzzer sound? Step 2 Step 3
2
1. Key “OFF”.
2. Disconnect ECM J1 connector.
3. Check for continuity between all wires
disconnected in “Step 1” and engine ground (–).
Is there continuity on PUR wire? 0 Ohms Step 4 Step 3
Is there continuity on TAN/WHT wire? 0 Ohms Step 4 Step 3
Is there continuity on BLU/TAN wire? 0 Ohms Step 4 Step 3
3 Circuit(s) is not shorted to ground (–). – –
4 Repair short-to-ground (–) in affected circuit. – –
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Index