(Table 227, contd)
Troubleshooting Test Steps
Values Results
3. Check the Duty Cycle of the Digital Throttle Position
Sensor
A. Access the following screens on the electronic service tool
in order to check the upper and the lower diagnostic limit of
the throttle position sensors:
· “Service”
· “Throttle Configuration”
· “Throttle# 1”
B. Make a note of the lower diagnostic limit and the upper di-
agnostic limit.
C. Verify that the keyswitch is in the ON position.
D. Access the following screens on the electronic service tool
in order to monitor the duty cycle of the throttle position:
· “Status”
· “Throttles”
E. Monitor the duty cycle of the throttle at the “low idle” posi-
tion and the “high idle” position.
Duty cycle above
lower diagnostic limit
at low idle
Duty cycle below
upper diagnostic limit
at high idle
Result: OK - The digital throttle position sensor is oper-
ating correctly.
Return the engine to service.
Result: Not OK - The digital throttle position sensor cir-
cuit is not operating correctly.
Proceed to Test Step 4.
4. Check the Supply Voltage at the Digital Throttle Posi-
tion Sensor
A. Turn the keyswitch to the OFF position.
B. Install a breakout “T” with three terminals at the suspect
digital throttle position sensor connector.
C. Turn the keyswitch to the ON position.
D. Measure the voltage between the +8 VDC terminal and the
sensor return terminal.
7.5 VDC to 8.5 VDC Result: The sensor supply voltage is not within the ex-
pected range. The fault is in the sensor supply wiring or
the ground wiring between the sensor and the ECM.
Repair: Repair the faulty wiring or replace the faulty
wiring.
Use the electronic service tool to clear all logged diag-
nostic codes and verify that the repair eliminates the
fault.
Result: The sensor supply voltage is within the expected
range.
Proceed to Test Step 5.
(continued)
UENR4469-36 429
Circuit Tests
Copyright of Perkins Engine Company Limited. NOT FOR REPRINTING OR RESALE
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