
46 RENR9348-01
Troubleshooting Section
Unit Injectors
1. Check the connectors at the Electronic Control
Module (ECM). Check for correct installation
of the J1/P1 an
d J2/P2 ECM connectors. Also,
thoroughly inspect the unit injector wiring harness
from the ECM to the J300/P300 valve cover entry
connector. R
efer to the diagnostic functional test
Troubleshooting, “Electrical Connectors - Inspect”.
2. Perform the “
Injector Solenoid Test” on Cat ET in
order to determine if all of the injector solenoids
are being energized by the ECM.
3. Perform the “Cylinder Cutout Test” on Cat ET
in order to identify any injectors that may be
misfiring. Re
fer to the diagnostic functional test
Troubleshooting, “Injector Solenoid Circuit - Test”.
Valve Lash
Check the engine valve lash settings. Inspect the
valve train
for sufficient lubrication. Check damage to
valve train components which may cause excessive
valve lash. Repair any problems that are found.
Refer to tr
oubleshooting without a diagnostic code
Troubleshooting, “Excessive Valve Lash”.
Cylinder H
ead and Related Components
Check for signs of damage and/or wear to the valves,
cylinder h
ead gasket, etc. Inspect the condition of
the camshafts.
i02422401
Poor Acceleration or Response
SMCS Code
: 1000-035
Probable
Causes
•
Engine derate or active codes
•
Cold mode
•
Flash file
•
Throttle signal
•
Electrical connectors
•
Unit inje
ctors
•
Intake manifold pressure
•
Air inlet and exhaust system
•
Fuel supp
ly
Recommended Ac
tions
Note: If the problem only occurs under certain
conditions, te
st the engine under those conditions.
Examples of certain conditions are high engine
speed, full load and engine operating temperature.
Troubleshoot
ing the symptoms under other
conditions can give misleading r esults.
Engine Derat
eorActiveCodes
Some engine monitoring parameters that are capable
of triggerin
g an engine derate do not produce an
event code. Connect Caterpillar Electronic Technician
(ET) in order to check for a derate of the engine.
Certain diagnostic codes and/or event codes may
cause poor performance. Use Cat ET to check for
active codes
and for logged codes. Troubleshoot any
codes that are present before continuing with this
procedure.
Note: Although a sensor’s signal may be in the
operational range of the sensor, the signal may
not repres
ent the actual reading. Use Cat ET to
check that the pressures and the temperatures are
fluctuating. Also check that the values are reasonable
for the con
ditions that are present.
Cold Mode
Use Cat ET to verify that the engine has exited
cold mode. Cold mode operation may slow throttle
response.
Flash File
Verify that the latest flash file is installed in the
Electronic Control Module (ECM).
Throttle Signal
Monitor t
he status for “Throttle Position” on Cat ET.
Verify that the status for “Throttle Position” is stable
and that the engine is able to reach high idle speed.
Refer to T
roubleshooting, “Speed Control - Test” for
information that is related to testing the system.
Electri
cal Connectors
Check for correct installation of the J1/P1 and J2/P2
Electro
nic Control Module (ECM) connectors and the
J300/P300 connectors for the unit injectors. Refer to
Troubleshooting, “Electrical Connectors - Inspect”.