Perkins M190C Troubleshooting Manual page 181

KENR9126
E. Measure the voltage between P1:15 (Unswitched
Battery+) and P1:9 (Battery-).
F. Measure the voltage between P1:16 (Unswitched
Battery+) and P1:10 (Battery-).
G. Measure the voltage between P1:40 (keyswitch)
and P1:3 (Battery-).
H. Turn the keyswitch to the OFF position.
Expected Result:
For 12 Volt systems, the measured voltage is a
constant 11.0 to 13.5 Volts DC with no suspected
intermittent faults at this time.
For 24 Volt systems, the measured voltage is a
constant 22.0 to 27.0 Volts DC with no suspected
intermittent faults at this time.
Results:
• OK – The ECM is receiving the correct voltage.
Repair: If an intermittent condition is suspected,
refer to Troubleshooting, "Electrical Connectors -
Inspect".
STOP.
•
Not OK – The ECM is not receiving the correct
voltage.
Repair: Check for continuity in the harness for
the keyswitch from P1:40 through the keyswitch
circuit to the batteries. Check the circuit protection
for the circuit. Refer to the service manual for the
instructions on troubleshooting the circuit for the
keyswitch.
For intermittent problems such as intermittent
shutdowns that could be caused by the application
wiring, temporarily bypassing the application wiring
may be an effective means of determining the root
cause.
Proceed to Test Step 5.
•
Not OK – No voltage is present on P1: 7, 8, 15, 16.
Repair: Check for continuity in the harness for the
unswitched Battery+ from the ECM to the batteries.
Check the circuit protection for the circuit. Check
for continuity in the harness for the Battery- from
the ECM to the batteries.
For intermittent faults such as intermittent
shutdowns that could be caused by the application
wiring, temporarily bypassing the application wiring
may be an effective means of determining the root
cause.
Proceed to Test Step 5.
• Not OK – The battery voltage is out of limits.
Proceed to Test Step 4.
Test Step 4. Check the Batteries
A. Measure the no-load battery voltage at the battery
terminals.
B. Load test the batteries. Use a suitable battery
load tester.
Expected Result:
The batteries pass the load test. For 12 Volt systems,
the measured voltage is at least 11.0 Volts DC. For
24 Volt systems, the measured voltage is at least
22.0 Volts DC.
Results:
• OK – The batteries pass the load test. For 12
Volt systems, the measured voltage is at least
11.0 Volts DC. For 24 Volt systems, the measured
voltage is at least 22.0 Volts DC.
Repair: Refer to the service manual for the
application for instructions on troubleshooting the
application harness. Troubleshoot the application
harness and repair the application harness, as
required.
Use the electronic service tool in order to clear all
logged diagnostic codes and then verify that the
repairs eliminate the fault.
STOP.
• Not OK – The batteries do not pass the load test.
For 12 Volt systems, the measured voltage is
less than 11.0 Volts DC. For 24 Volt systems, the
measured voltage is less than 22.0 Volts DC.
Repair: Recharge or replace the faulty batteries.
Use the electronic service tool in order to clear all
logged diagnostic codes and then verify that the
repair eliminates the fault.
STOP.
181
Troubleshooting Section