KENR6933 165
Troubleshooting Section
•
“Cylinder Cutout Test”
D. Select the start button at the bottom of the screen
for the cylinder cutout test on the electronic
service tool.
E. Select the “Cylinder Cutout Test”.
F. Follow the instructions that are provided in the
cylinder cutout test. The cylinder cutout tests are
interactive s
o the procedure is guided to the finish.
Note: The “Manual Cylinder Cutout Test” is also
available. A
ccess the manual test by selecting the
“Change” button on the screen for the cylinder cutout
test. The “Cylinder Cutout Test” is the recommended
starting pro
cedure. The automated tests run twice
collecting data. The two sets of data are analyzed
andan“OK”or“NotOK”resultisdisplayed.
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 cyli
nders indicate “OK”.
Repair: If the engine is misfiring or if the
engine has l
ow power, refer to Troubleshooting,
“Engine Misfires, Runs Rough or Is Unstable”
and Troubleshooting, “Low Power/Poor or No
Response t
o Throttle”.
If a diagnostic code results from running the
cylinder c
utout test, proceed to Test Step 5.
•
Not OK – One or more cylinders displayed “Not
OK” during
the test. Proceed to Test Step 5.
Test Step 5. Check the Harness between
the E CM and the Valve Cover Base for an
Open Circ
uit
Electrical shock hazard. The electronic unit inje c-
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 bo
th ends of the wire.
E. Insert one end of the jumper wire into the terminal
for the suspec
t 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.
G. Repeat this test for each suspect injector. Stop
the “Injector Solenoid Test” before handling the
jumper wires
.
Expected Result:
The electronic service tool displays “Current Above
Normal” for the cylinder with the jumper wire.
Results:
•
OK – The harne
ss between the ECM and the
valve cover base is OK. Proceed to Test Step 6.
•
Not OK – Ther
e is a fault between the ECM and
thevalvecoverbase.ProceedtoTestStep7.
Test Step 6.
Check the Injector Harness
Under the Va
lve C over
Electrical shock hazard. The electronic unit injec-
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. Remove the valve cover.
C. On six cylinder engines, disconnect the harness
from the suspect injector. Disconnect the harness
from the injectors that share the same supply
circuit as the suspect injector.
Note: On six cylinder engines, injectors 1, 2, and 3
share a common injector driver circuit in the ECM.
Injectors 4, 5, and 6 share a common injector driver
circuit in the ECM. If the three injectors that share a
common supply indicate “Open Circuit” fault codes,
the open circuit is probably caused by a faulty ECM.
D.
E. Thoroughly clean the terminals on the injectors
and on the harness connectors.
F. Exchange the harness between two of the
injectors that share the common driver.
To Next Page
Loading...
