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 1.0 volt at closed throttle to 4.0 volts at Wide Open Throttle (WOT).
The TP signal is one of the most important inputs used by the PCM for fuel control and most of the PCM controlled outputs. If the PCM detects a TP signal that is intermittently above the range of the TP sensor, DTC P1121 will be set.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
| • | TP sensor indicates a throttle position voltage intermittently greater than 4.7 volts. |
| • | The condition is present for longer than 5 seconds. |
Action Taken When the DTC Sets
The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.
Conditions for Clearing the MIL/DTC
| • | The DTC becomes history when the conditions for setting the DTC are no longer present. |
| • | The history DTC clears after 40 malfunction free warm-up cycles. |
| • | The PCM receives a clear code command from the scan tool. |
Diagnostic Aids
Check for the following conditions:
Important: : Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.
| • | Poor terminal connection. |
| Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension. Refer to Intermittents and Poor Connections Diagnosis , and Connector Repairs Wiring Systems. |
| • | Damaged harness. |
| Inspect the wiring harness for damage. If the harness appears to be OK, observe the sensor display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the sensor display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems. |
| • | Inspect the PCM and the engine grounds for clean and secure connections. |
If the DTC is determined to be intermittent, reviewing the Fail Records can be useful in determining when the DTC was last set.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain on Board Diagnostic System Check performed? | -- | ||||||||
2 | Select DTC info, Last Test Fail and note any other DTCs set. Is DTC P0123 also set? | -- | Go to DTC P0123 Throttle Position (TP) Sensor Circuit High Voltage | |||||||
3 | Is DTC P1111, P1115, and/or P1106 also set? | -- | ||||||||
4 | Check for a poor sensor ground circuit terminal connection at the TP sensor. ssary. Refer to Testing for Continuity Intermittents and Poor Connections Diagnosis Repairing Connector Terminals and Connector Repairs . Was a problem found? | -- | ||||||||
5 | Check the TP signal circuit between the TP sensor connector and the PCM for an intermittent short to voltage. ssary. Refer to Testing for Continuity Intermittents and Poor Connections Diagnosis Repairing Connector Terminals and Connector Repairs . Was a problem found? | -- | ||||||||
6 | Check for an intermittent short to voltage on the 5 Volt Reference A circuit between the PCM and the following components:
Was a problem found? | -- | ||||||||
7 | Check for a poor sensor ground terminal connection at the PCM. ssary. Refer to Testing for Continuity Intermittents and Poor Connections Diagnosis Repairing Connector Terminals and Connector Repairs . Was a problem found? | -- | ||||||||
8 | Check for an intermittent open or a faulty splice in the sensor ground circuit. ssary. Refer to Testing for Continuity Intermittents and Poor Connections Diagnosis Repairing Connector Terminals and Connector Repairs . Was a problem found? | -- | Go to Diagnostic Aids | |||||||
9 | Replace the faulty harness connector terminal for sensor ground circuit. ssary. Refer to Testing for Continuity Intermittents and Poor Connections Diagnosis Repairing Connector Terminals and Connector Repairs . Is the action complete? | -- | -- | |||||||
10 | Repair intermittent open/short circuit in wiring harness as necessary. ssary. Refer to Testing for Continuity Intermittents and Poor Connections Diagnosis Repairing Connector Terminals and Connector Repairs . Is the action complete? | -- | -- | |||||||
11 |
Does scan tool indicate DTC P1121 failed? | -- | System OK |
