P0122

DTC P0122 Throttle Position (TP) Sensor Circuit Low Voltage (1 Of 2):

DTC P0122 Throttle Position (TP) Sensor Circuit Low Voltage (2 Of 2):

Throttle Position (TP) System:

CIRCUIT DESCRIPTION


The Throttle Position (TP) sensor has a potentiometer whose resistance changes along with the throttle valve position. The Engine Control Module (ECM) provides a 5 volt reference voltage to the TP sensor. The ECM reads the voltage across the TP sensor and converts it into throttle position. When the TP sensor resistance decreases, the throttle valve opening is increasing to wide open throttle, and the voltage being monitored at the ECM increases. When the TP sensor resistance increases, the throttle valve opening is decreasing to idle, and the voltage being monitored at the ECM decreases.


CONDITIONS FOR SETTING THE DTC

- Low voltage input at the ECM indicated with the engine running (less than 4%).

- Above condition is met for at least 5 seconds.


ACTION TAKEN WHEN THE DTC SETS

- The Malfunction Indicator Lamp (MIL) will illuminate.

- The ECM 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.

- DTC(s) can be cleared by using a scan tool or by disconnecting the ECM battery feed.


DIAGNOSTIC AIDS

Check the following conditions:

- Poor connection at ECM. Inspect harness connectors for backed out terminal, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.

- Damaged 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 mis-adjusted TP sensor could cause the malfunction to set. Refer to TP sensor for adjustment procedures.

If 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.

If any wiring repairs need to be made, Refer to Repair Procedures in Diagrams.

TEST DESCRIPTION


Number(s) below refer to the step number(s) on the Diagnostic Table.

1. The Engine 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.

2. Determine if fault is present, vehicle must be at operating temperature.

3. Review Freeze Frame data to determine when the DTC set. Always record this information.

10. Refer to TP sensor for adjustment procedures.