Perkins NJ Series Troubleshooting Manual page 200

200
Troubleshooting Section
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 – There may be a fault with the ECM.
Repair: Temporarily connect a test ECM.
Remove the jumper wire from connector P2 and
reinstall the injector wires.
Perform the "Injector Solenoid Test".
If the test ECM fixes the fault, reconnect the
suspect ECM.
If the fault returns with the suspect ECM, replace
the ECM. Refer to the Troubleshooting Guide,
"Replacing the ECM".
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 8. Check the Harness between
the ECM and the Valve Cover Base for a
Short 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 the connectors from the valve cover
base.
C. Turn the keyswitch to the ON position.
D. Perform the "Injector Solenoid Test" at least two
times.
Expected Result:
All cylinders indicate "Current Below Normal".
Results:
• OK – All cylinders indicate "Current Below
Normal". Proceed to Test Step 10.
• Not OK – One or more cylinders indicate "Current
Above Normal". Note the cylinders that indicate
"Current Above Normal". Proceed to Test Step 9.
Test Step 9. Check the ECM for a Short
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 and check
for evidence of moisture entry.
C. Turn the keyswitch to the ON position.
D. Perform the "Injector Solenoid Test" at least two
times.
Expected Result:
All cylinders indicate "Current Below Normal" when
connector P2 is disconnected from the ECM.
Note: When the engine harness is disconnected,
all of the diagnostic codes for supply voltage to the
sensors will be active. This is normal. Clear all of the
logged diagnostic codes after completing this test
step.
Results:
• OK – The short circuit is in the engine harness.
Repair: The fault is most likely in one of the wires
to the injector. Inspect the connectors for moisture
and for corrosion. Also, check the wire insulation
for damage and for strands that are exposed.
Repair the engine harness or replace the engine
harness, as required. Clear all diagnostic codes
after completing this test step.
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 – There may be a fault with the ECM.
Repair: Temporarily connect a test ECM.
Perform the "Injector Solenoid Test".
SENR9982-01