Perkins NJ Series Troubleshooting Manual page 199

SENR9982-01
D. 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.
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.
G. Turn the keyswitch to the ON position.
H. 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 eliminates the fault.
STOP.
• Not OK – The injector may be faulty.
Repair: Replace the faulty injector. Refer to
Disassembly and Assembly, "Electronic Unit
Injectors - Remove" and Disassembly and
Assembly, "Electronic Unit Injectors - Install".
Restore the wiring to the correct injectors.
Perform the "Injector Solenoid Test".
Use the electronic service tool in order to clear all
logged diagnostic codes and then verify that the
repair eliminates the fault.
STOP.
Test Step 7. Check the ECM for an Open
Circuit
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. 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:
Perkins EST displays "Current Above Normal" for the
cylinder with the jumper wire.
Note: On four cylinder engines, shorting a shared
supply will affect the status of two injectors. Ignore
the status of the other injector that is on the shared
supply.
Note: On six cylinder engines, shorting a shared
supply will affect the status of three injectors. Ignore
the status of the other injectors that are on the shared
supply.
Results:
•
OK – The ECM is OK.
Repair: On four cylinder engines, if the two
injectors that share a supply indicate "Open Circuit"
fault codes, the open circuit is probably caused by
a faulty ECM.
On six cylinder engines, if the three injectors that
share a supply indicate "Open Circuit" fault codes,
the open circuit is probably caused by a faulty
ECM.
Repair the engine harness or replace the engine
harness, as required.
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Troubleshooting Section