Code 42: IC Circuit (Scan)
(2 of 2)
DIAGNOSTIC AIDS:
Any circuitry that is suspected as causing the inter-
mittent complaint should be thoroughly checked for
backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, poor
terminal-to-wiring connections, corroded terminals
and/or wiring, or physical damage to the wiring har-
ness. After repairs, clear codes following “Clearing
Codes” in “ECM Self-Diagnostics.” Failure to do so
may result in codes not properly being cleared.
Refer to “Intermittents” in “Troubleshooting.”
An intermittent problem may be caused by a poor or
corroded connection, rubbed through wire connec-
tion, a wire that is broken inside the insulation, or a
corroded wire.
1
2
•
•
CLEAR CODES.
IDLE ENGINE FOR 1 MINUTE OR UNTIL CODE 42 SETS.
DOES CODE 42 SET?
YES
NO
•
•
•
•
•
IGNITION “OFF.”
DISCONNECT ECM CONNECTORS.
IGNITION “ON.”
USE DVM WITH SELECTOR IN OHMS RANGE.
PROBE ECM HARNESS CONNECTOR CKT 423 WITH
DVM TO GROUND.
CODE 42 INTERMITTENT. REFER TO
“DIAGNOSTIC AIDS” ABOVE.
IT SHOULD READ MORE THAN 3000 OHMS.
DOES IT?
YES
NO
•
PROBE ECM HARNESS CONNECTOR CKT 424 WITH
A TEST LIGHT TO BATTERY VOLTAGE.
OPEN CKT 423. FAULTY CONNECTION
OR FAULTY IGNITION MODULE.
LIGHT “OFF”
LIGHT “ON”
3
4
•
WITH OHMMETER STILL CONNECTED TO ECM HARNESS CKT
AND GROUND, AGAIN PROBE ECM HARNESS CKT 424
WITH THE TEST LIGHT CONNECTED TO BATTERY VOLTAGE.
(AS TEST LIGHT CONTACTS CKT 424, RESISTANCE SHOULD
SWITCH FROM OVER 3000 TO UNDER 1000 OHMS.)
DOES IT?
•
DISCONNECT IGNITION MODULE 4-WAY CONNECTOR.
423
LIGHT “ON”
LIGHT “OFF”
CKT 424 SHORTED
TO GROUND.
FAULTY IGNITION
MODULE.
NO
YES
5
•
RECONNECT ECM AND IDLE ENGINE FOR
ONE MINUTE OR UNTIL MALFUNCTION IN
DICATOR “ON.”
•
DISCONNECT DIST. 4-WAY CONNECTOR. NOTE
OHMMETER THAT IS STILL CONNECTED TO CKT
AND GROUND. RESISTANCE SHOULD HAVE
423
GONE HIGH (OPEN CIRCUIT).
DOES IT?
YES
NO
YES
NO
CKT 424 OPEN. FAULTY
CONNECTIONS OR FAULTY
IGNITION MODULE.
CKT 423
SHORTED TO
GROUND.
FAULTY ECM
CODE 42 INTERMITTENT.
REFER TO “DIAGNOSTIC
AIDS” ON FACING PAGE.
NOTE:CLEAR DIAGNOSTIC TROUBLE CODE (DTC) STOP ENGINE FOR AT LEAST ONE MINUTE AFTER REPAIR IS PER-
FORMED. RESTART ENGINE AND CHECK FOR CODES.
Index
90-823224--2 796
ELECTRONIC FUEL INJECTION (MULTI-PORT AND THROTTLE BODY) - 5C-109
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 454 CID, Mercury MerCruiser 502 CID |
| Model Year | 1993, 1994, 1995, 1996, 1997 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(4 votes, average: 4.5 out of 5)
Marine readers have rated 1993 1997 Mercury-MerCruiser GM V8 454 CID 7.4L and 502 CID 8.2L Marine Engines Service Manual Number 16 4.5 out of 5.0 based on 4 product reviews. Hugely helpful service manual! Perfect. Thank you!
Manuals are all Important for Technician
This book is invaluable if you do your own repairs. Great book.
Could not find a copy until a search brought me here.
Excellent print.
Thank you