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 1.0 volt at closed throttle to above 4.0 volts at Wide Open Throttle (WOT). If the PCM detects a TP signal voltage that is intermittently greater than the range of the TP sensor, DTC P1121 will be set.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
TP sensor intermittently indicates a throttle position signal greater than 4.9 volts.
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:
| • | Poor connection at the PCM or the TP sensor. |
| Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. Use a corresponding mating terminal to test for proper tension. |
| • | 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 malfunction. |
If DTC P1121 cannot be duplicated, reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the OBD Diagnostic System Check? | -- | ||
2 | Select Diagnostic Trouble Codes (DTCs) and note if any other DTCs are 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 | Test all 5 volt reference A circuits and connected components for an intermittent short to voltage. Refer to Wiring Repairs . Did you find and correct the condition? | -- | Go to Diagnostic Aids | |
5 | Test the signal circuit of the TP sensor for an intermittent short to voltage. Refer to Wiring Repairs . Did you find and correct the condition? | -- | ||
6 | Test the ground circuit of the TP sensor for an intermittent open. Refer to Wiring Repairs . Did you find and correct the condition? | -- | ||
7 | Inspect for poor connections at the harness connector of the TP sensor. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | ||
8 | Inspect for poor connections at the harness connector of the PCM. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs . Did you find and correct the condition? | -- | Go to Diagnostic Aids | |
9 |
Does scan tool indicate DTC P1121 failed? | -- | System OK |
