GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1999 🢒 Corvette 🢒 Engine 🢒 Engine Controls - 5.7L 🢒 DTC P0507 Idle Speed High

Circuit Description

The Throttle Actuator Motor is a TAC controlled DC motor located on the throttle body. The motor drives the throttle plates. In order to decrease idle speed, the TAC commands the throttle closed reducing air flow into the engine and the idle speed decreases. In order to increase idle speed, the TAC commands the throttle plates open allowing more air to bypass the throttle plates. If the Actual idle RPM does not match the Desired idle RPM within a calibrated time, this DTC sets.

Conditions for Running the DTC
    • DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0125, P0171, P0172, P0174, P0175, P0200, P0300, P0440, P0442, P0443, P0500, P0502, P0503, P1120, P1220, P1221, P1441 not set.
    • The engine is operating for at least 60 seconds.
    • The ECT is greater than 60°C (140°F).
    • The IAT is greater than -10°C (14°F).
    • The BARO is greater than 65 kPa.
    • The system voltage is between 9 volts and 18 volts.
    • The vehicle speed is less than or equal to 1 mph.
    • The APP Indicated Angle is 0%.

Conditions for Setting the DTC
    • The actual idle speed is 200 RPM greater than the desired idle speed.
    • All of the above conditions present for 5 seconds.

Action Taken When the DTC Sets
    • The PCM illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
    • The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.

Conditions for Clearing the MIL/DTC
    • The PCM turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Use a scan tool in order to clear the MIL and the DTC.

Diagnostic Aids

Important: 

   • Remove any debris from the PCM\TAC module connector surfaces before servicing the PCM\TAC module. Inspect the PCM\TAC module connector gaskets when diagnosing/replacing the modules. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM\TAC modules.
   • For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616 . Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Wiring Systems.

    • The following may cause an intermittent:
       - Poor connections; Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
       - Mis-routed harness.
       - Rubbed through wire insulation.
       - Broken wire inside the insulation.
    • Using Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can aid in determining how many miles since the DTC set. The Fail Counter and Pass Counter can also aid determining how many ignition cycles the diagnostic reported a pass and/or a fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This isolates when the DTC failed.
    • For an intermittent, refer to Symptoms .

Test Description

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

  1. This test determines whether or not the engine can achieve the commanded RPM, and if not, whether the RPM is too high or too low.

Step

Action

Value(s)

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

  1. Start the engine.
  2. Command the engine speed up to 1500 RPM, down to 500 RPM, up to 1500 RPM, and then EXIT using the scan tool.

Does the engine speed correspond, within 100 RPM, with each command?

--

Go to Diagnostic Aids

Go to Step 3

3

Is the engine RPM greater than 100 RPM above Desired RPM?

--

Go to Step 4

Go to Step 5

4
  1. Inspect for the following conditions:
    2. • Vacuum leaks
    • A faulty PCV valve
  2. If you find a condition repair the condition as necessary.

Is the action complete?

--

Go to Step 6

--

5
  1. Inspect for the following conditions:
    2. • Excessive deposits in the throttle body
    • Parasitic load on the engine (i.e. transmission problem etc.)
  2. If you find a condition repair the condition as necessary.

Is the action complete?

--

Go to Step 6

--

6
  1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information option using the scan tool.
  2. Idle the engine at the normal operating temperature.
  3. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
  4. Operate the vehicle within the conditions for running this DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test ran and passed?

--

Go to Step 7

Go to Step 2

7

Select the Capture Info option and the Review Info option using the scan tool.

Does the scan tool display any DTCs that you have not diagnosed?

--

Go to the applicable DTC table

System OK