The throttle position (TP) sensor is a potentiometer. The TP sensor is mounted on the side of the throttle body. The TP sensor provides a voltage signal that changes relative to throttle blade angle. This signal voltage is one of the most important inputs used by the powertrain control module (PCM). The TP sensor has a 5.0 volt reference, a ground, and a signal circuit. The signal voltage varies from below 1 volt at closed throttle to about 4 volts at wide open throttle (WOT).
Engine running..
• | TP sensor signal voltage is less than 0.1 volt. |
• | Above conditions are present for longer than 1 second. |
• | The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
• | The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records. |
• | The PCM turns the MIL Off after three consecutive drive trips that the diagnostic runs and does not fail. |
• | A last test failed (current DTC) clears when the diagnostic runs and does not fail. |
• | A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures. |
• | Use a scan tool in order to clear the MIL/DTC. |
• | Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module (PCM) Description , Clearing Diagnostic Trouble Codes. |
Notice: Use the connector test adapter kit J 35616-A for any test that
requires probing the following items:
• The PCM harness connectors • The electrical center fuse/relay cavities • The component terminals • The component harness connector
Check for a malfunctioning TP sensor: With the key ON, engine not running, observe the TP sensor display on the scan tool while slowly depressing the accelerator to wide open throttle. If a voltage under 0.16 volts is seen at any point in normal accelerator travel, replace the TP sensor.
If DTC P0122 cannot be duplicated, the information included in the Fail Records data can be useful in determining vehicle mileage since the DTC was last set.
If the problem is intermittent, refer to Intermittent Conditions .
Number(s) below refer to the step number(s) on the Diagnostic Table:
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
2 | With the throttle closed, observe the TP Sensor display on the scan tool. Is TP Sensor display less than the specified value? | 0.16V | ||
3 |
Does the scan tool indicate DTC P0122 failed? | -- | Refer to Diagnostic Aids. | |
4 |
Is TP Sensor near the specified value? | 5V | ||
5 |
Is TP Sensor near the specified value? | 5V | ||
6 |
Was a problem found and corrected? | -- | ||
7 |
Was a problem found and corrected? | -- | ||
8 |
Was a problem found and corrected? | -- | ||
9 |
Was a problem found and corrected? | -- | ||
10 |
Was a problem found and corrected? | -- | ||
11 |
Was a problem found and corrected? | -- | ||
12 | Replace the TP sensor. Refer to Throttle Position Sensor Replacement . Is the action complete? | -- | -- | |
Replace the PCM. Important: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming Is action complete? | -- | -- | ||
14 |
Does the scan tool indicate that this test ran and passed? | -- | ||
15 | Review Captured Info using the scan tool. Are there any DTCs that have not been diagnosed? | -- | Go to the applicable DTC table
| System OK |