P0122

Steps 1 - 4:

Steps 5 - 10:

Steps 11 - 12:

DTC P0122 Throttle Position (TP) Sensor Circuit Low Voltage




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 below 0.6 volts at closed throttle to about 4.5 volts at wide open throttle (WOT). The TP signal is used by the powertrain control module (PCM) for fuel control and many of the PCM-controlled outputs.

Conditions for Setting the DTC
- The ignition is ON.
- TP sensor signal voltage is less than 0.22 volt for a total of 0.78 second over a 1.5-second period.

Action Taken When the DTC Sets
- The PCM will illuminate the malfunction indicator lamp (MIL) the first time the fault is detected.
- The PCM will store conditions which were present when the DTC was set as Freeze Frame and in the Failure Records data.
- The PCM will use a default throttle position based on mass air flow and RPM.

Conditions for Clearing the MIL/DTC
- 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.
- A history DTC P0122 will clear after 40 consecutive warm-up cycles have occurred without a fault.
- DTC P0122 can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed.

Diagnostic Aids
Check for the following conditions:
- 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.
- The TP Sensor shares a 5 Volt reference with the EGR valve. If these codes are also set, it could indicate a problem with the 5 Volt reference circuit or components itself.
- The TP Sensor shares a ground with the EGR Valve and the IAT Sensor
- Damaged harness - Inspect the wiring harness for damage. If the harness appears to be OK, observe the throttle position display on the scan tool while moving connectors and wiring harnesses related to the TP sensor. A change in the display will indicate the location of the fault.

If DTC P0122 cannot be duplicated, the information included in the Failure Records data can be useful in determining vehicle mileage since the DTC was last set. If it is determined that the DTC occurs intermittently, performing the DTC P1122 Diagnostic Chart may isolate the cause of the fault.