192 KENR9126
Troubleshooting Section
Note: Do not confuse the “Injector Solenoid Test”
with the “Cylin
der Cutout Test”. The “Cylinder Cutout
Test” is used to shut off fuel to a specificcylinder
while the engine is running. The “Injector Solenoid
Test” is used t
o actuate the injector solenoids while
the engine is not running. This allows the click of the
injector solenoids to be heard while the engine is off
in order to de
termine that the circuit is functioning
correctly.
G. As each sole
noid is energized by the ECM, an
audible click can be heard at the valve cover.
Expected Re
sult:
All cylinders indicate “OK”.
Results:
•
OK –Therei
s not an electronic fault with the
injectors at this time.
Repair: I
f the “Injector Solenoid Test” returned a
“Not OK” for any injector, refer to Troubleshooting,
“Engine Misfires, Runs Rough or Is Unstable”.
STOP.
•
Open – No
te the cylinders that indicate “Open”.
Proceed to Test Step 5.
•
Short – N
ote the cylinders that indicate “Short”.
Proceed to Test Step 4.
Test St
ep 4. Check the Variation of the
Injec
tors between Cylinders
A. Start the engine.
B. Allow the engine to warm up to normal operating
temperature.
C. After the engine is warmed to operating
temperature, access the “Cylinder Cutout Test” by
acce
ssing the following display screens in order:
•
“Diagnostics”
•
“Diagnostic Tests”
•
“Cy
linder Cutout Test”
D. Select the start button at the bottom of the screen
fo
r the cylinder cutout test on the electronic
service tool.
E. Se
lect the “Cylinder Cutout Test”.
F. Follow the instructions that are provided in the
c
ylinder cutout test. The cylinder cutout tests are
interactive so the procedure is guided to the finish.
Note: The “Manual Cylinder Cutout Test” is also
available. Acc
ess the manual test by selecting the
“Change” button on the screen for the cylinder cutout
test. The “Cylinder Cutout Test” is the recommended
starting proc
edure. The automated tests run twice
collecting data. The two sets of data are analyzed
and an “OK” or “Not OK” result is displayed.
G. Check for active diagnostic codes and for logged
diagnostic codes that are related to the injector
solenoids.
Expected Result:
All cylinders indicate “OK” on the electronic service
tool.
Results:
•
OK – All cyl
inders indicate “OK”.
Repair: If the engine is misfiring or if the
engine ha
s low power, refer to Troubleshooting,
“Engine Misfires, Runs Rough or Is Unstable”
and Troubleshooting, “Low Power/Poor or No
Response
to Throttle”.
If a diagnostic code results from running the
cylinde
r cutout test, proceed to Test Step 5.
•
Not OK – One or more cylinders displayed “Not
OK” d uri
ng the test. Proceed to Test Step 5.
Test Step 5. Check the Harness between
the ECM and the Va lve Cover Base for a n
Open C
ircuit
Electrical shock hazard. The electronic unit i njec-
tor system uses 67-73 volts.
A. Turn the keyswitch to the OFF position. A strong
electrical shock hazard is present if the keyswitch
is not turned OFF.
B. Disconnect the connectors from the valve cover
base.
C. Turn the keyswitch to the ON position.
D. Fabricate a jumper wire 100 mm (4 inch) long with
terminals on both ends of the wire.
E. Insert one end of the jumper wire into the terminal
for the suspect injector's supply. Insert the other
end of the jumper wire into the terminal for the
suspect injector's return circuit.
F. Perform the “Injector Solenoid Test” at least two
times.
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