Perkins NJ Series Troubleshooting Manual page 169

SENR9982-01
Expected Result:
A Voltage Below Normal diagnostic code or an
Voltage Above Normal diagnostic code is active.
Results:
• OK - SHORT Circuit – A Voltage Below Normal
diagnostic code is active at this time. Proceed to
Test Step 4.
•
OK - OPEN Circuit – An Voltage Above Normal
diagnostic code is active at this time. Proceed to
Test Step 5.
• Not OK – A Voltage Below Normal diagnostic code
is not active. An Voltage Above Normal diagnostic
code is not active. An intermittent fault may exist.
Repair: By using the Perkins EST, perform a
"Wiggle Test". If faults are indicated then go to the
appropriate procedure.
STOP.
Test Step 4. Disconnect The Sensor In
Order To Create An Open Circuit.
A. Turn the keyswitch to the OFF position.
B. Disconnect the sensor connector of the sensor
with the short circuit diagnostic code.
C. Turn the keyswitch to the ON position.
Note: Wait at least 10 seconds for activation of the
diagnostic codes.
D. Access the "Active Diagnostic Code" screen of the
Perkins EST. Check for an active Voltage Above
Normal diagnostic code.
Expected Result:
An Voltage Above Normal diagnostic code for the
disconnected sensor is now active.
Results:
• OK – A Voltage Below Normal diagnostic code
was active before disconnecting the sensor. An
Voltage Above Normal diagnostic code became
active after disconnecting the sensor.
Repair: Refer to Troubleshooting, "Electrical
Connectors - Inspect".
Inspect the seals of the connectors for damage.
Connect the sensor and verify that the fault returns.
If the fault returns, the sensor is faulty.
Replace the sensor.
Clear all logged diagnostic fault codes.
STOP.
•
Not OK – There is a short circuit between the
sensor harness connector and the ECM. Leave the
sensor disconnected. Proceed to Test Step 6.
Test Step 5. Create A Short Circuit
Between The Signal And The Common
Terminals At The Sensor Harness
Connector.
A. Disconnect the suspect sensor connector P100
for the coolant temperature sensor or disconnect
P103 for the inlet manifold temperature sensor.
B. Turn the keyswitch to the ON position.
Note: Wait at least 10 seconds for the activation of
any diagnostic fault codes.
C. Fabricate a jumper wire 150 mm (6 inch) long.
Crimp a terminal to both ends of the wire.
D. Monitor the "Active Diagnostic Code" screen on
the Perkins EST before installing the jumper wire
and after installing the jumper wire.
E. Install the jumper on the engine harness connector
for the suspect sensor, P100 for the coolant
temperature sensor and P103 for the intake
manifold temperature sensor. Install one end
of the jumper at the sensor signal (terminal 1).
Install the other end of the jumper at the common
connection (terminal 2).
Note: Wait at least 30 seconds for activation of the
short circuit diagnostic code.
Expected Result:
A Voltage Below Normal diagnostic code is active
when the jumper is installed. An Voltage Above
Normal diagnostic code is active when the jumper
is removed.
Results:
• OK – The engine harness and the ECM are OK.
Repair: Perform the following repair:
1. Temporarily connect the suspect sensor.
2. If the diagnostic code remains active, replace
the sensor.
3. Verify that the repair eliminates the fault.
4. Clear all logged diagnostic codes.
STOP.
169
Troubleshooting Section