Audio Warning Buzzer Circuit Check
(1 of 2)
TAN/
BLU
PPPLUR
D
C
B
A
121
TAN
TO BUZZER
TO IGN
3 PNK
TO SYSTEM
RELAY TERM
“87”
TO AUDIO
WARNING
SWITCHES
BLU/
TAN
TO TACH
GRY
COOLANT OVERTEMP
(TO BUZZER)
121
WHT
LOW OIL PRESSURE/
LOW I/O FLUID (TO BUZZER)
(TRANS. TEMP. MIE)
TO
IGN
COIL
TO LOW OIL PRESSURE
AND GEAR LUBE SWITCHES
(TRANS. TEMP. MIE)
931 BRN
J1-6
CIRCUIT DESCRIPTION:
4. This step identifies if the fault is a short in the har-
ness or a faulty ECM.
The audio warning buzzer function of the ECM is
used to alert the operator of a critical engine function
parameter. Used in conjunction with the discrete in-
put circuitry, the ECM will supply ignition current to
activate the buzzer if a change of state is indicated by
any of the discrete inputs. When a discrete switch
changes state from normally open to closed, the
ECM interprets that an anomaly is present and will
complete the ground to the affected buzzer circuit,
energizing the buzzer.
5. This step checks for an open in the circuitry from
the harness connector to the ignition fuse.
6.
This step identifies if the open circuit is due to a
faulty ECM or warning buzzer circuitry.
DIAGNOSTIC AIDS:
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.
TEST DESCRIPTION:
Number(s) below refer to circled number(s) on the
functional check chart.
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.
1.
2.
3.
This step performs a functional check of the
buzzer circuit.
This step identifies a short to ground in the control
circuit.
This step identifies an open in the control circuit.
Index
5C-82 - ELECTRONIC FUEL INJECTION (MULTI-PORT AND THROTTLE BODY)
90-823224--2 796
| 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.
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