For 1990-2009 cars
Engine Controls Components
Engine Data Sensors
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

### 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 powertrain control module (PCM) detects a TP signal voltage that is intermittently less than the range of the TP sensor, DTC P1122 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 less than 0.1 volt.

### 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

Inspect for the following conditions:

Many situations may lead to an intermittent condition. Perform each inspection or test as directed.

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.

• | Loose terminal connection

- | Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.

- | Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Refer to Testing for Intermittent Conditions and Poor Connections , and to Connector Repairs in Wiring Systems for diagnosis and repair.

• | Damaged harness--Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

• | Inspect the powertrain control module (PCM) and the engine grounds for clean and secure connections. Refer to Wiring Repairs in Wiring Systems for diagnosis and repair.

If the condition is determined to be intermittent, reviewing the Snapshot or Freeze Frame/Failure Records may be useful in determining when the DTC or condition was identified.

### Test Description

The numbers below refer to the step numbers on the diagnostic table:

1. This test will determine an intermittent faulty TP sensor utilizing the DMMs MIN MAX 100 millisecond capture mode.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check
2 | Is DTC P0122 also set? | -- | Go to DTC P0122 Throttle Position (TP) Sensor Circuit Low Voltage | Go to Step 3
3 | Test the 5 Volt Reference circuit of the TP sensor for an intermittent open, high resistance and short to ground.

1. Turn OFF the ignition.
2. Disconnect the TP sensor.
3. Connect a DMM between the TP sensor 5 volt reference circuit at the TP harness connector and ground.
4. Turn ON the Ignition.
5. Lightly touch and wiggle the related engine wiring harnesses and connectors for all 5 volt reference circuits while observing voltage. Any change in voltage indicates the area where a 5 volt reference circuit fault may be found. Refer to Circuit Testing and Wiring Repairs and Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 4

4 | Test the signal circuit of the TP sensor for an intermittent open, high resistance and short to ground.

1. Reconnect the TP sensor.
2. Install a scan tool and go to the TP voltage parameter.
3. Lightly touch and wiggle the related engine wiring harnesses and connectors for the TP signal circuit while observing voltage. Any change in voltage indicates the area where a TP signal circuit fault may be found. Refer to Circuit Testing and Wiring Repairs and Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 5

5 | Inspect for poor connections at the harness connector of the TP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 6
6 | Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 9 | Go to step 7
7 |

1. Connect two jumper wires at the TP sensor, one at the signal terminal, one at the 5 volt reference terminal.
2. With a DMM set to 40k ohms scale connect the DMM to the jumper wires.
3. Ensure a good, proper connection at the TP sensor and DMM test leads.
4. Press the MIN MAX button on the DMM.
5. Slowly depress the acclerator pedal to Wide Open Throttle (WOT) and back to the closed throttle position several times.
6. Press the MIN MAX button and record the MAX reading.
7. Press the MIN MAX button again and record the MIN reading.
8. Remove the jumper wire at the 5 volt reference terminal and connect it to the ground terminal and repeat steps 2 through 7.

Did you record a MAX value of OL or a record a MIN value of 0 ohms in either test?

--

Go to step 8

Go to Diagnostic Aids

8 | Replace the TP sensor. Refer to Throttle Position Sensor Replacement . Did you complete the replacement? | -- | Go to step 9 | --
9 |

1. Use a scan tool in order to clear the DTC's.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC run and pass?

--

System OK

Go to Step 2