Code 33: MAP Circuit (Non-Scan)
(2
of 2)
1
•
•
IGNITION “OFF.”
DISCONNECT VACUUM PLUG LOCATED UNDER
PLENUM AT FRONT AND INSTALL A VACUUM
GAUGE IN THE VACUUM PORT.
•
START ENGINE AND RAISE RPM TO ABOUT 1000
RPM. VACUUM GAUGE READING SHOULD BE 14in.
Hg (45.5 kPa) OR MORE AND STEADY. IS IT?
YES
NO
3
2
REPAIR LOW OR UNSTEADY
VACUUM PROBLEM.
•
•
IGNITION “OFF.”
REMOVE VACUUM GAUGE AND REINSTALL VACUUM
PLUG IN VACUUM PORT.
•
•
•
DISCONNECT MAP SENSOR ELECTRICAL CONNECTOR.
IGNITION “ON.”
CONNECT A DVM FROM HARNESS TERMINAL “C” (CKT
416,
5 VOLT REFERENCE) TO HARNESS TERMINAL “A”
(CKT 814, SENSOR GROUND).
IS VOLTAGE READING OVER 4 VOLTS?
YES
NO
5
6
4
•
CONNECT DVM FROM HARNESS TERMINAL “C”
(CKT 416) TO HARNESS TERMINAL “B” (MAP
SENSOR SIGNAL, CKT 432).
•
CONNECT DVM FROM MAP SENSOR HARNESS
TERMINAL “C” TO A GOOD GROUND ON ENGINE.
IS VOLTAGE OVER 4 VOLTS?
IS VOLTAGE READING OVER 4 VOLTS?
YES
NO
NO
YES
•
•
IGNITION “OFF.”
CONNECT DVM
FAULTY CONNECTION AT ECM
OR
CKT 416 OPEN
OR
SHORTED TO GROUND
OR
FAULTY ECM.
FAULTY CONNECTION
AT ECM
OR
CKT 814 OPEN
OR
FAULTY ECM.
BETWEEN HARNESS
TERMINAL “B” AND
ENGINE GROUND.
IS VOLTAGE OVER 4
VOLTS?
CONNECT A TEST LIGHT TO
BATTERY POSITIVE B+.
TOUCH TEST LIGHT TO HARNESS
TERMINAL “B” (MAP SENSOR
SIGNAL). IS TEST LIGHT “ON”?
•
YES
NO
YES
NO
•
•
DISCONNECT ECM.
MAP
SENSOR
FAULTY.
CKT 432
SHORTED
TO VOLTAGE.
OPEN CKT 432
OR
FAULTY
CONNECTION
AT ECM
OR
TOUCH TEST LIGHT
CONNECTED TO
BATTERY POSITIVE
B+ TO HARNESS
TERMINAL “B”.
IS TEST LIGHT
“ON”? SEE NOTE
FAULTY ECM.
NO
CKT 432 SHORTED
TO GROUND.
FAULTY ECM.
NOTE: USING A TEST LIGHT WITH 100 mA OR LESS RATING MAY
SHOW A FAINT GLOW WHEN TEST ACTUALLY STATES NO LIGHT.
Index
90-823224--2 796
ELECTRONIC FUEL INJECTION (MULTI-PORT AND THROTTLE BODY) - 5C-93
| 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