
160 RENR9348-01
Troubleshooting Section
•
“Diagnostics”
•
“Diagnostic Tests”
•
“Cylinder Cuto
ut Test”
D. Shut off all parasitic loads such as air compressors
which could af
fect the results of the test.
E. Follow the instructions that are given on the
screen.
F. To start the test, select the start button at the
bottom of the s
creen.
G. Use Cat ET to manually cut out the cylinders
in order to ide
ntify injectors that may have a
performance problem. Highlight a cylinder and
select the “Change” button at the bottom of
the screen. T
he injector for that cylinder will be
disabled. Check for a difference in the sound, feel,
or power of the engine. Also, look for a change to
the operati
ng parameters that are displayed on
the “Cylinder Cutout Test” screen.
Expected Re
sult:
The cylinder cutout test indicates that all of the
injectors a
re operating correctly.
Results:
•
OK – The cylinder cutout test indicates that all of
the injectors are operating correctly.
Repair: If a problem with the fuel system is
suspected and diagnostic codes are not active or
logged, re
fer to Systems Operation/Testing and
Adjusting for information that is related to the low
pressure fuel system.
STOP.
•
Not OK – The
cylinder cutout test indicates that at
least one of the injectors is not operating correctly.
Proceed to Test Step 4.
Test Step 4. Perform the “Injector
Solenoid Test”
A. Start the
engine.
B. Allow the engine to warm up to normal operating
temperat
ure 77 °C (171 °F).
C. Stop the engine.
D. Restore the electrical power to the ECM.
E. Access th
e “Injector Solenoid Test” by accessing
the following display screens:
•
“Diagnostics”
•
“Diagnostic Tests”
•
“Injector Sole
noid Test”
F. Activate the “Injector Solenoid Test”.
G. As each solenoid is energized by the ECM, an
audible click can be heard at the valve cover.
Allow the “Inj
ector Solenoid Test” to continue until
each cylinder is activated at least two times.
Expected Resu
lt:
All cylinders indicate “OK” on Cat ET.
Results:
•
OK – There is no
t an electronic problem with the
injectorsatthistime.
Repair: The p
roblem appears to be resolved.
There may be an intermittent problem in the
harness. The problem may have been caused by a
poor electri
cal connection in a connector.
If the codes continue to be logged, refer to
Troubleshoo
ting, “Electrical Connectors - Inspect”.
If the engine is misfiring or if the engine has low
power, refer
to Troubleshooting, “Engine Misfires,
Runs Rough or Is Unstable” or Troubleshooting,
“Low Power/Poor or No Response to Throttle”.
STOP.
•
Not OK - “Ope
n” – Note the cylinder that indicates
“Open”. Proceed to Test Step 5.
•
Not OK - “Sho
rt” – Note the cylinder that indicates
“Short”. Proceed to Test S tep 6.
Test Step 5.
Check the Harness between
the ECM an d
the Valve Cover Base for an
Open Circuit
Electrical shock hazard. The electronic unit injec-
tor system uses 90-120 volts.
A. Remove the electrical power from the ECM.
B. Disconnect the appropriate P300 connector at the
valve cover base.
C. Restore the electrical power to the ECM.