Perkins M190C - Page 151

KENR9126 151
Troubleshooting Section
Te st Step 3. Verify that the Diagnostic
Code is Still Active
A. Turn the keyswitch to the ON position. Wait at
least 10 seconds for activation of the diagnostic
codes.
B. Use the electronic service tool to check for active
diagnostic
codes. Record all active diagnostic
codes.
C. Determine i
f the fault is related to an open circuit
diagnostic code or a short circuit diagnostic code.
Expected R
esult:
Either a short circuit diagnostic code is active or an
open circu
it diagnostic code is active.
Results:
•
OK - SHORT Circuit – A “Voltage Above Normal”
diagnostic code is active at this time. Proceed to
Test Ste
p4.
•
OK - OPEN Circuit – A “Voltage Below Normal”
diagnos
tic code is active at this time. Proceed to
Test Step 5.
•
Not OK –
A short circuit diagnostic code is not
active. An open circuit diagnostic code is not
active. An intermittent fault may exist.
Repair: Use the electronic service tool to perform
a “Wiggle Test”. If faults are indicated then go to
the ap
propriate procedure.
STOP.
Test Step 4. Disconnect Th e Sensor In
OrderToCreateAnOpenCircuit
A. Turn
the keyswitch to the OFF position.
B. Disconnect the sensor connector of the sensor
wit
h the short circuit diagnostic code.
C. Turn the keyswitch to the ON position. Wait at
lea
st 10 seconds for activation of the diagnostic
codes.
D. Us
e the electronic service tool to check the “Active
Diagnostic Code” screen. Check for a “Voltage
Below Normal” diagnostic code.
Expected Result:
A
“Voltage Below Normal” diagnostic code for the
disconnected sensor is now active.
Results:
•
OK – A “Voltage Above Normal” diagnostic code
was active before disconnecting the sensor . An
“Voltage Belo
w Normal” diagnostic code became
active after disconnecting the sensor. Proceed to
Test Step 6.
•
Not OK – There is a short circuit between the
sensor connector on the harness and the ECM.
Leave the se
nsor disconnected. Proceed to Test
Step 8.
Test Step 5.
Measure the Sensor Supply
Voltage
A. Turn the keyswitch to the OFF position.
B. Disconnect the sensor from the engine harness.
C. Turn the k
eyswitch to the ON position.
D. Measure the voltage at the plug for the sensor
from the t
erminal 1 (pressure sensor supply) to
terminal 2 (sensor common).
Expecte
dResult:
The DC voltage from terminal 1 to terminal 2
measure
s4.84to5.16VDC.
Results:
•
OK – The sensor supply voltage is correct.
ProceedtoTestStep7.
•
Not OK – The sensor supply voltage is out of the
nominal range. Continue testing the sensor supply
circu
it.
Repair: Proceed to the following repair:
Trou
bleshooting, “5 Volt Sensor Supply Circuit -
Test”
STOP
.
Test Step 6. Determine If The Short
Circuit Is In Th e Connector Or In The
Sen
sor
A. Thoroughly inspect the connector for moisture.
B. Inspect the seals and reconnect the sensor.
C. Re
fer to Troubleshooting, “Electrical Connectors
- Inspect”.
D
.
I
f the short circuit diagnostic code reappears, the
sensor or the sensor connector has a fault.
a
.
T
emporarily connect a new sensor to the
harness, but do not install the new sensor in
the engine.