6E2–130
6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Trouble Code (DTC) P0123 TP Sensor Circuit High Voltage
D06RW059
Circuit Description
The throttle position (TP) sensor circuit provides a voltage
signal that changes relative to throttle blade angle. The
signal voltage will vary from about 0.6 volts at closed
throttle to about 4.5 volts at wide open throttle (WOT).
The TP signal is one of the most important inputs used by
the powertrain control module (PCM) for fuel control and
many of the PCM-controlled outputs.
Conditions for Setting the DTC
D
The ignition is “ON.”
D
TP sensor signal voltage is greater than 4.88 volts for
a total of 0.78 second over a 1.5-second period.
Action Taken When the DTC Sets
D
The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
D
The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
D
The PCM will use a default throttle position based on
mass air flow and RPM.
Conditions for Clearing the MIL/DTC
D
The PCM will turn the MIL “OFF” on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.
D
A history DTC P0123 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
D
DTC P0123 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:
D
The TP sensor shares a 5 Volt Reference with the EGR
Position sensor. Check the 5 Volt reference if these
DTCs are also set.
D
The TP sensor shares a ground with the IAT sensor
and the EGR position Sensor. Check the ground if
these other DTCs are also set.
D
Poor connection at PCM – Inspect harness connectors
for backed-out terminals, improper mating, broken
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.
D
Damaged harness – Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
TP sensor display on the Tech 2 while moving
connectors and wiring harnesses related to the TP
sensor. A change in the display will indicate the
location of the fault.
D
Faulty TP sensor – With the ignition key “ON,” engine
“OFF,” observe the TP sensor display on the Tech 2
while slowly depressing the accelerator to wide open
throttle. If a voltage over 4.88 volts is seen at any point
in normal accelerator travel, replace the TP sensor.
If DTC P0123 cannot be duplicated, the information
included in the Failure Records data can be useful in
determining vehicle mileage since the DTC was last set.