
34 RENR5622
Troubleshooting Section
i02418891
Replacing the ECM
SMCS Code: 1901
-038
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 troubleshooting procedures in this
manual in order to be sure that replacing the ECM
will correct the problem. Verify that the suspect ECM
is the 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 a replacement of the ECM is attempted.
Refer to Troubleshooting, “Electrical Power Supply”.
NOTICE
If the flash file and engine application are not matched,
engine damage may result.
Perform the following procedure in order to replace
the ECM.
1. Record the configuration data:
a. Connect Ca
terpillar Electronic Technician (ET)
to the service tool connector for the engine.
b. Print the parameters from the “Configuration”
screen on Cat ET
. If a printer is unavailable,
record all of the parameters. Record any
logged diagnostic codes and logged event
codes for your
records. Record the injector
trim codes from the “Calibrations” screen in the
“Service” menu on Cat ET.
Note: The injector trim code is a number that is found
on each of the unit injectors. The ECM uses this
number to com
pensate for manufacturing variations
between individual injectors. If you replace any of
the unit injectors, you must reprogram the injector
trim code fo
r the new injectors. Also, if you replace
the ECM, you must reprogram all of the injector trim
codes.
c. Copy the settings for the engine monitoring
system. Refer to Troubleshooting, “Event Code
List”.
d. Use the “Copy Configuration/ECM
Replaceme
nt” feature that is found under the
“Service” menu on Cat ET. Select “Load from
ECM” in order to copy the configuration data
from the su
spect ECM.
Note: If the “Copy Configuration” process fails and
the param
eters were not obtained in Step 1.b, the
parameters must be obtained elsewhere. Some of the
parameters are stamped on the engine information
plate. Mo
st of the parameters must be obtained from
the factory.
2. Remove th
eECM.
a. Remove electrical power from the ECM.
b. Disconnect the ECM connectors J1/P1 and
J2/P2.
NOTICE
Use a suit
able 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 from the ECM (if
equipped).
d. Remove the mounting bolts from the ECM.
e. Disconnect the ECM ground strap from the
engine.