Indicator Lamp Circuit - Test - Perkins NJ Series Troubleshooting Manual

SENR9982-01
D. Remove the fuses from the +Battery wire of the
bypass harness and connect the +Battery and the
Battery wires directly to the battery terminals.
Note: This bypass directly connects the circuit for the
keyswitch to the ECM. The ECM will remain powered
until the connection to the unswitched battery + line
is disconnected. Remove the fuses from the in-line
fuse holder to power down the ECM. Do not connect
the bypass to the battery terminals or do not remove
the bypass from the battery terminals without first
removing the in-line fuses.
E. Connect the Perkins EST to the diagnostic
connector of the bypass harness and verify that
communication can be established.
Note: Remove the bypass harness and restore all
wiring to the original condition after testing.
Expected Result:
Installing the bypass eliminates the fault.
Note: The status of the "Ignition Keyswitch" will
always indicate ON while the bypass harness is
installed.
Results:
•
OK – The symptoms disappear when the bypass
harness is installed. Also, the symptoms return
when the bypass harness is removed. The fault
is in the wiring for the application that supplies
power to the ECM. Check for aftermarket engine
protection switches that interrupt power. Send the
application to the OEM dealer to repair. STOP.
• Not OK
Repair: Connect the bypass to another battery and
verify if the fault is resolved. If the fault is resolved,
the fault is with the batteries on the application.
If the fault still exists, temporarily connect a
test ECM. Remove all jumpers and replace
all connectors. Recheck the system for active
diagnostic codes and repeat the Test Step. If the
fault is resolved with the test ECM, reconnect the
suspect ECM. If the fault returns with the suspect
ECM, replace 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.

Indicator Lamp Circuit - Test

System Operation Description:
Use this procedure under the following circumstances:
•
The lamps are not receiving battery voltage.
• The lamps are not operating correctly.
Also, use this procedure if another procedure has
directed you here.
The following diagnostic lamps are available:
• Power Take Off (PTO) lamp
• Stop lamp
•
Warning lamp
• Cold start (wait to start lamp)
• Low oil pressure lamp
The Perkins Electronic Service Tool (EST) can be
used as a diagnostic aid in order to switch the
individual lamps ON and OFF.
Note: The diagnostic aid function that switches the
lamps is contained in the "Override" section in the
"diagnostics" menu of the Perkins EST.
187
Troubleshooting Section
i02491535