Engine Electrical System

Diagnostic trouble code: P0123 “Overvoltage in circuit for throttle position
sensor”
Item
No.
Operation procedure
Inspection
results
Follow-up
procedure
1
Connect the diagnostic tester and adaptor,
and turn the ignition switch to “ON”
position.
Proceed to next
step.
Yes
Proceed to next
step.
2
Observe the item of “throttle absolute
opening” in the data flow to verify that
the value is maintained within 4%-10%
(the exact value varies from individual
auto model.)
No Proceed to Step5
Yes
Proceed to next
step.
3
Step on the accelerator pedal slowly until
full opening, observe the “absolute
opening of throttle” in data flow and
verify that the value is increased to
85%-95% with the increasing of the
accelerator pedal opening (the exact value
varies from individual auto model).
No Proceed to Step5
Yes Replace the sensor.
4
Repeat the step 3, observe the “absolute
opening of throttle” in data flow to verify
that there is jump during the change of
the value.
No
Proceed to next
step.
Yes
Repair and replace
the wiring harness.
5
Disconnect the connector of the throttle
position sensor on the wiring harness to
verify that the circuits between 17#, 32#,
and 16# pins of ECU and 1#, 2#, and 3#
pins of the sensor connector are open or
short to power supply.
No
Proceed to next
step.
Yes Replace the sensor.
6
Inspect with multimeter to verify that the
voltage between 1# and 2# pins of this
connector is about 5V.
No
Refer to diagnosis
help.
E-27
PDF created with pdfFactory Pro trial version www.pdffactory.com