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 circuits:

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

This provides the powertrain control module (PCM) 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 PCM detects that the TP sensor 2 signal voltage is less than the predicted range, DTC P0222 sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0222 Throttle Position (TP) Sensor 2 Circuit Low Voltage

Conditions for Running the DTC

    • The ignition switch is in the crank or run position.
    • DTC P0641 is not set.
    • The ignition voltage is more than 5.23 volts.
    • DTC P0222 runs continuously when the above conditions are met.

Conditions for Setting the DTC

The PCM detects that the TP sensor 2 voltage is less than 0.31 volts for more than 0.4 seconds.

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 PCM 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: Powertrain Control Module Connector End Views or Engine Controls Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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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 TP sensor 2 voltage parameter less than the specified value?

0.31 V

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 harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Observe the TP Sensor 2 Voltage parameter, with a scan tool.

Does the scan tool indicate voltage within the specified range?

4.8-5.2 V

Go to Step 5

Go to Step 6

5

Measure the voltage of the TP sensor 2 5-volt reference circuit to a good ground, with a DMM.

Does the DMM indicate voltage within the specified range?

4.8-5.2 V

Go to Step 8

Go to Step 7

6

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

Did you find and correct the condition?

--

Go to Step 12

Go to Step 10

7

Test the TP sensor 2 5-volt reference circuit for the following conditions:

    • An open
    • A short to ground
    • High resistance

Refer to Circuit Testing and Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 10

8

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

Did you find and correct the condition?

--

Go to Step 12

Go to Step 9

9

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

Did you complete the replacement?

--

Go to Step 12

--

10

Test for an intermittent and for a poor connection at the at the powertrain control module (PCM) harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 11

11

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

Did you complete the replacement?

--

Go to Step 12

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12

  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 13

13

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