MerCruiser 305 CID (5.0L) Service Manual page 714

SERVICE MANUAL NUMBER 24
Code 52 (1 of 1): EEPROM Failure
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 EFI.
DIAGNOSTIC AIDS:
If DTC 52 failed more than once, but is intermittent, replace the ECM.
Step
1.
2.
3.
Index
90-861327--1 OCTOBER 1999
Was the "On-Board Diagnostic" (OBD) System Check
Performed?
a. Clear trouble code 52.
b. Ignition ON.
Does trouble code 52 reset?
Replace faulty ECM and verify trouble code 52 does not
reset.
Action
DIAGNOSTICS
72801
Yes No
PROCEED TO
Step 2. OBD
Refer to
Diag-
nostic nostic
Step 3.
Aids
Verify
–
Repair
Page 5G-87