Code 42: IC Circuit (Non-Scan) (2 of 2)
DIAGNOSTIC AIDS:
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.
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.
Any circuitry that is suspected as causing the inter-
mittent complaint should be thoroughly checked for
1
•
•
•
INSTALL MARINE DIAGNOSTIC CODE TOOL.
CLEAR CODES (REFER TO CLEARING CODES).
IDLE ENGINE FOR 1 MINUTE OR UNTIL MALFUNCTION INDICATOR
LAMP COMES “ON.”
00000
•
•
IGNITION “ON,” ENGINE STOPPED.
ENTER SERVICE MODE ON CODE TOOL AND NOTE CODES.
CODE 42
NO CODE 42
2
•
•
•
•
•
IGNITION “OFF.”
DISCONNECT ECM CONNECTORS J1 AND J2
IGNITION “ON.”
DVOM SELECTOR SWITCH IN THE OHM RANGE
PROBE ECM HARNESS CONNECTOR CKT 423 WITH AN
OHMMETER TO GROUND.
CODE 42 INTERMITTENT. IF NO
ADDITIONAL CODES WERE STORED,
REFER TO “INTERMITTENTS” IN TROUBLE-
SHOOTING SECTION, OR “DIAGNOSTIC AIDS”
ABOVE WHERE APPLICABLE.
IT SHOULD READ MORE THAN 3KΩ OHMS.
DOES IT?
YES
NO
•
PROBE ECM HARNESS CONNECTOR CKT 424 WITH
A TEST LIGHT TO 12 VOLTS AND NOTE LIGHT.
OPEN CKT 423. FAULTY CONNECTION
OR FAULTY IGNITION MODULE.
LIGHT “OFF”
LIGHT “ON”
3
•
WITH OHMMETER STILL CONNECTED TO ECM HARNESS
CKT 423 AND GROUND, AGAIN PROBE ECM HARNESS
CKT 424 WITH THE TEST LIGHT CONNECTED TO 12
VOLTS. AS TEST LIGHT CONTACTS CKT 424,
RESISTANCE SHOULD SWITCH FROM OVER 3KΩ TO
UNDER 1KΩ OHMS.
•
DISCONNECT IGNITION MODULE 4-WAY
CONNECTOR.
LIGHT “ON”
LIGHT “OFF”
DOES IT?
CKT 424 SHORTED
TO GROUND.
FAULTY IGNITION
MODULE.
NO
YES
4
5
•
•
DISCONNECT DIST. 4-WAY CONNECTOR. NOTE OHM
METER THAT IS STILL CONNECTED TO CKT 423 AND
GROUND. RESISTANCE SHOULD HAVE GONE HIGH (OPEN
CIRCUIT). DOES IT?
RECONNECT ECM AND IDLE ENGINE FOR
ONE MINUTE OR UNTIL MALFUNCTION IN
DICATOR LAMP COMES “ON.”
LIGHT “ON”
LIGHT “OFF”
YES
NO
CODE 42
CODE 42 INTERMITTENT.
CKT 424 OPEN. FAULTY
CONNECTIONS OR FAULTY
IGNITION MODULE.
CKT 423
SHORTED TO
GROUND.
FAULTY ECM
NO TROUBLE FOUND. CHECK
HARNESS AND CONNECTORS FOR AN
INTERMITTENT OPEN OR SHORT TO
GROUND IN CKT 423 AND 424.
Index
90-823224--2 796
ELECTRONIC FUEL INJECTION (MULTI-PORT AND THROTTLE BODY) - 5C-95
| 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