Perkins NJ Series Troubleshooting Manual page 216

216
Troubleshooting Section
Test Step 3. Jumper the Switch Input at
the Throttle Switch Connector
A. Disconnect the throttle switch connector P503.
B. Observe the status of the suspect throttle input on
Perkins EST.
C. Use a suitable jumper wire to short P503:1 to the
terminal for the suspect throttle input at throttle
switch connector P503.
D. Observe the status of the suspect throttle input on
Perkins EST.
E. Remove the jumper wire.
Expected Result:
The status of the suspect throttle input should be
OFF when throttle switch connector J503/P503 is
disconnected. The status should be ON when the
jumper wire is installed.
Results:
• OK – The harness and the ECM are OK.
Repair: Replace the throttle switch.
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 – Proceed to Test Step 4.
Test Step 4. Check for Shorts in the
Harness
A. Turn the keyswitch to the OFF position.
B. Disconnect the P1 connector and the throttle
switch connector P503/J503.
C. Measure the resistance between engine ground
and the terminal for the suspect throttle input at
the throttle switch connector P503.
D. Measure the resistance between the terminal for
the suspect throttle input at the throttle switch
connector P503 and the remaining terminals at
the connector.
Expected Result:
Resistance should be greater than 20,000 Ohms for
each reading.
Results:
• OK – Proceed to Test Step 5.
•
Not OK – There is a short in the harness between
the ECM and the throttle switch.
Repair: Repair the circuit.
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 5. Check Resistance through
the Harness
A. Use a jumper wire to short P503:1 to the terminal
of the suspect throttle input at the throttle switch
connector J503.
B. Measure the resistance between P1:35 and the
terminal for the suspect throttle input on the P1
connector.
Expected Result:
Resistance should be less than 10 Ohms.
Results:
• OK – Proceed to Test Step 6.
•
Not OK – There is an open circuit or excessive
resistance in the harness.
Repair: Repair the circuit.
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 6. Check the Harness and the
ECM
A. Turn the keyswitch to the OFF position.
B. Disconnect the P1 connector and remove the
wire for the suspect throttle input from the P1
connector.
C. Reconnect all connectors.
D. Turn the keyswitch to the ON position.
E. Observe the status of the suspect throttle input on
Perkins EST.
SENR9982-01