TROUBLE CODE DIAGNOSTICS - 7.4L MPI
SERVICE MANUAL NUMBER 23
Code 51 (1 of 2): Calibration Memory Failure (Non-Scan)
72801
CIRCUIT DESCRIPTION:
This test allows the ECM to check for a calibration failure by comparing the calibration value
to a known value stored in the EEPROM.
This test is also used as a security measure to prevent improper use of calibrations or
changes to these calibrations that may alter the designed function of the EFI system.
DIAGNOSTIC AIDS:
If DTC 51 failed more than once, but is intermittent, replace the ECM.
TEST DESCRIPTION:
Number(s) below refer to step number(s) on the diagnostic table.
Step 2. This step checks to see if the fault is present during diagnosis. If present, the
ECM is not functioning properly and must be replaced.
STEP
ACTION
VALUE
YES
NO
PROCEED TO
Go to
Was the “On-Board Diagnostic” (OBD) System
Check Performed?
OBD
System
Check
1
2
–
Step 2
1. Install Marine Diagnostic Code Tool.
2.
trouble code 51.
Using clear trouble code procedure, clear
Refer to
Diag-
nostic
Aids
3.
4.
the “Service Mode”.
Ignition “ON”.
Switch Marine Diagnostic Code Tool to
Does trouble code 51 reset?
–
–
Step 3
Replace faulty ECM and verify trouble code
does not reset. Is action complete?
Verify
–
3
Repair
Page 5G-36
90-861326--1 MARCH 1999
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 454 CID, Mercury MerCruiser 502 CID |
| Model Year | 1998, 1999, 2000, 2001 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(1 votes, average: 5 out of 5)
Marine readers have rated Mercury MerCruiser GM V8 GM V8 454 CID 7.4L and 502 cid 8.2L Marine Engines Service Manual Number 23 5.0 out of 5.0 based on 1 product reviews. Just need the manual. Wrote review. Can't technically review what I haven't seen yet...