P0122

Wiring Diagram:

Circuit Description
The Throttle Position (TP) sensor contains a potentiometer whose resistance value changes along with the throttle valve position. The Powertrain Control Module (PCM) provides a 5 volt reference voltage to the TP sensor. The PCM reads the voltage across the TP sensor and converts it into the throttle position. The TP sensor resistance decreases as the throttle valve opening increases. When the TP sensor resistance decreases the voltage being monitored at the PCM will increase. And when the TP sensor resistance increases, because the throttle valve opening is decreasing, the voltage being monitored at the PCM will decrease.

Conditions for Setting the DTC
^ Low voltage input at the PCM indicated with the engine running.
^ Above condition is met for at least 5 seconds.

Action Taken When the DTC Sets
^ The Malfunction Indicator Lamp (MIL) will illuminate.
^ The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame buffer.

Conditions for Clearing the MIL/DTC
^ The MIL will turn off after three consecutively passing cycles without a fault present.
^ A History DTC will clear after 40 consecutive warm-up cycles without a fault.
^ DTCs can be cleared by using a scan tool or by disconnecting the PCM battery feed.

Diagnostic Aids
Check for any of the following conditions:
^ A poor connection at the PCM. Inspect the harness connectors for backed out terminal, improper mating, broken locks, improperly formed or damaged terminals, and a poor terminal to wire connection.
^ A damaged wiring harness. Inspect the wiring harness for damage. If the harness appears to be OK, observe the TP display on the scan tool while moving connectors and wiring harnesses related to the TP sensor. A change in the TP display will indicate the location of the fault.
^ A misadjusted TP sensor could cause the malfunction to set. Refer to TP Sensor Adjustment.

If the DTC P0122 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining vehicle operating conditions when the DTC was first set.

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
1. The OBD System Check prompts the technician to complete some basic checks and store the freeze frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
3. This step determines if DTC P0123 is the result of a hard failure or an intermittent condition.
4. When the 5 volt reference is jumpered to the TP input circuit, the scan tool parameter should read 99%.
5. When the TP sensor input circuit is jumpered to battery voltage, the scan tool parameter should read 99%.