
RENR9348-01 9
Troubleshooting Section
i02518796
Replacing the ECM
SMCS Code: 1901
-510
NOTICE
Care must be taken to ensure that fluids are contained
during performance of inspection, maintenance, test-
ing, adjustin
g and repair of the product. Be prepared to
collect the fluid with suitable containers before open-
ing any compartment or disassembling any compo-
nent containi
ng fluids.
Refer to Special Publication, NENG2500, “Caterpillar
Dealer Servic
e Tool Catalog” for tools and supplies
suitable to collect and contain fluids on Caterpillar
products.
Dispose of all fluids according to local regulations and
mandates.
NOTICE
Keep all parts clean from contaminants.
Contaminants may cause rapid wear and shortened
component life.
The Electron
ic Control Module (ECM) contains no
moving parts. Replacement of the ECM can be costly.
Replacement can also be a time consuming task.
Follow the tr
oubleshooting procedures in this manual
in order to ensure that replacing the ECM will correct
the problem. Use these procedures to ensure that
the ECM is th
e cause of the problem.
Note: Ensure that the ECM is receiving power and
that the ECM
is properly wired to the negative battery
circuit before you attempt to replace the ECM. Refer
to the diagnostic functional test Troubleshooting,
“Electric
al Power Supply Circuit - Test”.
Some application software supports the use of a new
ECM as a tes
t ECM. A new ECM can be temporarily
placed into a “Test ECM Mode”. This ECM can
then be used to replace a suspect ECM in order
to determ
ineifthesuspectECMisfaulty.Referto
programming parameters Troubleshooting, “Test
ECM Mode”.
NOTICE
If the flas
h file and engine application are not matched,
engine damage may result.
Perform t
he following procedure in order to replace
the ECM:
1. Print the parameters from the “Configuration”
screen on Cater
pillar Electronic Technician
(ET). If a printer is unavailable, record all of the
parameters. Record any logged diagnostic codes
and logged eve
nt codes for your records. Record
the injector serial numbers from the “Calibrations”
screen under the “Service” menu on Cat ET.
Note: The injector serial numbers are necessary for
obtaining the correct injector trim files. The ECM
uses the inje
ctor trim files in order to compensate for
manufacturing variations between individual injectors.
If you replace any of the unit injectors, you must
reprogram t
he injector trim files for the new injectors.
Also, if you replace the ECM, the injector trim files
must be installed into the new ECM. A successful
“Copy Config
uration” process will accomplish this
task. For more instruction, refer to programming
parameters Troubleshooting, “Injector Trim File”.
2. Use the “Copy Configuration/ECM Replacement”
feature that is found under the “Service” menu on
Cat ET. Sel
ect “Load from ECM” in order to copy
the configuration from the suspect ECM.
Note: If th
e “Copy Configuration” process fails and
the parameters were not obtained in Step 1, the
parameters must be obtained elsewhere. Some
paramete
rs are stamped on the engine information
plate, but most parameters must be obtained from
the factory.
3. Remove the ECM from the engine.
a. Remove th
e electrical power from the ECM.
b. Disconnect the J1/P1 and J2/P2 ECM
connect
ors.
NOTICE
Use a suitable container to catch any fuel that might
spill. Clean up any spilled fuel immediately.
NOTICE
Do not allow dirt to enter the fuel system. Thoroughly
clean the area around a fuel system component that
will be disconnected. Fit a suitable cover over discon-
nected fuel system component.
c. Remove the fuel lines (if equipped) from the
ECM.
d. Remove the mounting bolts from the ECM.
e. Disconnect the ECM ground strap from the
engine.
4. Install the replacement ECM.