GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The throttle position (TP) sensor 1 and sensor 2 are located within the throttle body assembly. Each sensor has the following components:

    • A 5-volt reference circuit
    • A low reference circuit
    • A signal circuit

This provides the engine control module (ECM) with a signal voltage proportional to throttle plate movement. TP sensor 1 signal voltage at closed throttle is near the 5-volt reference and decreases as the throttle plate is opened. TP sensor 2 signal voltage at closed throttle is near the low reference and increases as the throttle plate is opened. If the ECM detects that the TP sensor 2 signal voltage is not within the predicted range, DTC P0223 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0223 Throttle Position (TP) Sensor 2 Circuit High Voltage

Conditions for Running the DTC

    • The ignition switch in the crank or run position.
    • DTC P0641 is not set.
    • The ignition voltage is more than 5.23 volts.
    • DTC P0223 runs continuously when the above conditions are met.

Conditions for Setting the DTC

The ECM detects that the TP sensor 2 voltage is more than 4.7 volts for more than 0.5 second.

Action Taken When the DTC Sets

    • The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
    • The control module commands the TAC system to operate in the Reduced Engine Power mode.
    • A message center or an indicator displays Reduced Engine Power.
    • Under certain conditions the control module commands the engine OFF.

Conditions for Clearing the MIL/DTC

    • The ECM will turn OFF the malfunction indicator lamp (MIL) during the third consecutive trip in which the diagnostic runs and passes.
    • The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using a scan tool.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

Connector End View Reference: Engine Controls Connector End Views or Engine Control Module Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn ON the ignition, with the engine OFF.
  2. Observe the throttle position (TP) sensor 2 voltage with the accelerator pedal in the rest position, with a scan tool.

Is the TP sensor 2 voltage parameter more than the specified value?

4.7 

Go to Step 4

Go to Step 3

3

  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the Conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

--

Go to Step 4

Go to Testing for Intermittent Conditions and Poor Connections

4

  1. Turn OFF the ignition.
  2. Disconnect the throttle body connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage of the TP sensor 2 5-volt reference circuit with a DMM

Does the DMM indicate voltage within the specified range?

4.8-5.2 V

Go to Step 5

Go to Step 10

5

With a test lamp connected to ground, probe the TP sensor signal circuit.

Does the test lamp illuminate?

--

Go to Step 8

Go to Step 6

6

Observe the TP sensor 2 parameter with a test lamp still connected to the TP sensor signal circuit.

Does the scan tool indicate voltage at the specified value?

0 V

Go to Step 9

Go to Step 7

7

Test the TP sensor 2 signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 13

8

Test the TP sensor 2 signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 11

9

Test the TP sensor 2 low reference circuit for an open or high resistance. Refer to Circuit Testingand Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 12

10

Test the TP sensor 2 5-volt reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 11

11

Test for shorted terminals and for a poor connection at the engine control module (ECM) harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 15

12

Test for an intermittent and for a poor connection at the throttle body harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 14

13

Test for an intermittent and for a poor connection at the ECM harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs.

Did you find and correct the condition?

--

Go to Step 16

Go to Step 15

14

Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement.

Did you complete the replacement?

--

Go to Step 16

--

15

Replace the ECM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 16

--

16

  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

--

Go to Step 2

Go to Step 17

17

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK