KENR9126 193
Troubleshooting Section
G. Repeat this test for each suspect injector. Stop
the “Injector S
olenoid Test” before handling the
jumper wires.
Expected Resu
lt:
The electronic service tool displays “Current Above
Normal” for t
he cylinder with the jumper wire.
Results:
•
OK – The harness between the ECM and the
valve cover base is OK. Proceed to Test Step 6.
•
Not OK – There is a fault between the ECM and
the valve cover base. Proceed to Test Step 7.
Test Step 6. Check the Injector Harness
Under the Valve Cover
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. Thoroughly clean the terminals on the injectors
and on the harness connectors.
E. Exchange the harness between two of the
injectors that share the common driver.
F. Turn the keyswitch to the ON position.
G. Perform the “Injector Solenoid Test” at least two
times.
Expected Result:
Exchanging the harness between the two injectors
caused the fault to move to the other injector.
Results:
•
OK – There is a fault with the injector harness
under the valve cover.
Repair: Repair the injector harness or replace the
injector harness under the valve cover.
Use the electronic service tool in order to clear all
logged diagnostic codes and then verify that the
repair elim
inates the fault.
STOP.
•
Not OK – The injector may be faulty.
Repair: Re
place the faulty injector.
Restore the wiring to the correct injectors.
Perform the “Injector Solenoid Test”.
Use the el
ectronic service tool in order to clear all
logged diagnostic codes and then verify that the
repair eliminates the fault.
STOP.
Test Ste
p7.ChecktheECMforanOpen
Circuit
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 connector P2 from the ECM.
C. Remove the supply wire and the return wire for
the suspect injector from connector P2. Install a
jumper wire into connector P2 in order to provide
a short between the supply and the return of the
suspect injector.
D. Reinstall connector P2 to the ECM.
E. Turn the keyswitch to the ON position.
F. Perform the “Injector Solenoid Test” at least two
times.
Expected Result:
The electronic service tool displays “Current Above
Normal” for the cylinder with the jumper wire.
To Next Page
