GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2003 🢒 Tracker - 4WD 🢒 DTC 🢒 DTC P0507
Table 1: IAC Valve Terminal (Pin) Location

Circuit Description

The DTC P0507 Idle Speed High diagnostic monitors the engine speed. The powertrain control module (PCM) controls the idle air control (IAC) valve in order to regulate the air flow through the idle air bypass passage. The amount of air flowing through the idle air bypass passage determines the idle speed. The PCM directs the IAC valve according to changes in the engine load. Higher than expected idle speeds can cause a DTC P0507 to set.

Conditions for Running the DTC
    • DTC P0500 is not set.
    • Barometric pressure (BARO) is more than 75 kPa.
    • Intake air temperature (IAT) is between -14° and +70°C (7-158°F).
    • Engine coolant temperature(ECT) is more than 70°C (158°F).
    • Engine is running in Closed Loop at idle
    • No vehicle speed is detected
    • The throttle valve is closed
    • A/C is OFF
    • The power steering pressure (PSP) switch is OFF.

Conditions for Setting the DTC
    • The actual engine speed is 200 RPM more than the desired engine speed value with the IAC Motor Command near 0 percent.
    • The above condition exists for more than 30 seconds.

Action Taken When the DTC Sets
    • The PCM illuminates the malfunction indicator lamp (MIL) after 2 consecutive ignition cycles in which the diagnostic runs with the fault active.
    • The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Freeze Frame buffer.

Conditions for Clearing the MIL/DTC
    • The MIL turns OFF after 3 consecutively passing trips without a fault present.
    • A history DTC clears after 40 consecutive warm-up cycles without a fault.
    • Perform the scan tool Clear DTC Information function.

Diagnostic Aids

The IAC Motor Command parameter of the scan tool will appear fixed when a Current or Pending DTC P0507 is set. Clear the DTC in order to observe present time IAC Motor Command readings.

Any malfunction that can cause a high idle condition can cause a DTC P0507 to set.

Check for the following conditions:

An intermittent malfunction may be caused by a fault in the idle air control (IAC) system electrical circuits. Check the wiring harness and components for an intermittent condition. Refer to Intermittent Conditions .

Use the following table in order to locate the correct terminals to test during diagnosis. The table layout corresponds to the pin location of the IAC valve electrical terminals.

IAC Valve Terminal (Pin) Location

Lock Tab

3

2

1

6

5

4

Test Description

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

  1. The Diagnostic System Check-Engine Controls prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

    2.

  2. This step prompts the technician to check for any condition that can affect the ability of the IAC valve to control engine idle speed. A DTC P0507 can set even if there is no fault in the IAC system. Any condition that can affect the idle speed of the engine must be repaired first, in order to enable proper diagnosis of the DTC P0507.

    3.

  3. This step tests whether the PCM can operate the IAC valve with the scan tool. The IAC valve can be commanded to increase and/or decrease engine speed by using the scan tool RPM Control function. The RPM Control function of the scan tool is disabled when any DTCs are set, and when the engine temperature is less than the normal operating temperature of 80°C (176°F).

    4.

  4. This step checks whether the malfunction that caused the DTC P0507 is still present. Operating the vehicle under these conditions will verify whether the fault is present. Clearing the DTCs by removing the DOME fuse also clears the PCM long term memory. Using the scan tool to clear DTCs leaves the long term memory active. DTC emitting diagnostics may not run to completion as expected unless the long term memory is cleared. Removal of the DOME fuse also clears the time display of the radio. The DTC P0507 diagnostic can be monitored on the scan tool under the Not Ran Since Code Cleared selection in the DTC Information menu. If a DTC P0507 appears in the Not Ran Since Code Cleared list, the DTC P0507 diagnostic has not yet run. When the DTC P0507 does not appear in the Not Ran Since Code Cleared list, the DTC P0507 diagnostic has run. If the MIL is NOT illuminated, and there is no Pending DTC Status in DTC Information, the DTC P0507 diagnostic has passed. The DTCs MUST be cleared in order to view the Current Status of the Not Ran Since Code Cleared list. DO NOT forget that the Not Ran Since Code Cleared list only indicates that the test has run, not whether the test passed or failed. The DTC Information screen must be checked for Current or Pending status, in order to determine the outcome of the diagnostic test involved.

    5.

  5. This step determines whether the PCM is attempting to control the IAC valve. Each IAC coil control circuit should indicate a high voltage of 12 volts or more and then a low voltage of 0.0-1.0 volts as the PCM commands changes in the engine speed. Remember to perform this test at normal engine operating temperatures and clear all DTCs before attempting RPM control with the scan tool.

    6.

  6. Clearing the DTCs by removing the DOME fuse also clears the PCM long term memory. Using the scan tool to clear DTCs leaves the long term memory active. DTC emitting diagnostics may not run to completion as expected unless the long term memory is cleared. Removal of the DOME fuse also clears the time display of the radio. The DTC P0507 diagnostic can be monitored on the scan tool under the Not Ran Since Code Cleared selection in the DTC Information menu. If a DTC P0507 appears in the Not Ran Since Code Cleared list, the DTC P0507 diagnostic has not yet run. When the DTC P0507 does not appear in the Not Ran Since Code Cleared list, the DTC P0507 diagnostic has run. If the MIL is NOT illuminated, and there is no Pending DTC Status in DTC Information, the DTC P0507 diagnostic has passed. The DTCs MUST be cleared in order to view the Current Status of the Not Ran Since Code Cleared list. DO NOT forget that the Not Ran Since Code Cleared list only indicates that the test has run, not whether the test passed or failed. The DTC Information screen must be checked for Current or Pending status, in order to determine the outcome of the diagnostic test involved.

Step

Action

Value(s)

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

  1. Inspect the engine for any of the following conditions:
    2. • A stuck or binding throttle valve, accelerator cable, or accelerator pedal
    • Any vacuum or intake air leaks
    • An evaporative emission (EVAP) system malfunction
    • An incorrect throttle position (TP) sensor, engine coolant temperature (ECT) sensor, or mass air flow (MAF) sensor input
  2. Repair the condition as necessary.

Did you find and correct a condition?

--

Go to Step 4

Go to Step 3

3

  1. Start the engine.
  2. Operate the engine at normal operating temperatures.
  3. Perform the scan tool Clear DTC Information function.
  4. Select RPM Control, under IAC System, in the Special Functions menu of the scan tool. Refer to Scan Tool Output Controls
  5. Command the IAC valve to increase and decrease the engine speed with the scan tool.

Does the engine speed increase and decrease as commanded by the scan tool?

--

Go to Step 4

Go to Step 6

4

  1. Turn OFF the ignition.
  2. Remove the DOME fuse for 30 seconds.
  3. Install the DOME fuse.
  4. Reset the radio clock time. Refer to Radio/Audio System Description and Operation in Entertainment.
  5. Start the engine.
  6. Operate the vehicle within the Freeze Frame conditions as specified or until the DTC P0507 diagnostic test has run. Refer to the Test Description.

Is DTC P0507 set?

--

Go to Step 6

Go to Step 5

5
  1. Start the engine.
  2. Turn OFF all accessories.
  3. Operate the engine at a normal operating temperature.
  4. Observe the Engine Speed and the IAC Motor Command parameters on the scan tool.

Are the Engine Speed and the IAC Motor Command parameters within the specified ranges?

700-800 RPM in P/N

10%-50% IAC Motor Command

System OK

Go to Rough, Unstable, or Incorrect Idle and Stalling

6
  1. Turn OFF the ignition.
  2. Disconnect the IAC valve electrical connector.
  3. Measure the resistance of the following IAC valve coil windings with a DMM:
    4. • Between pin 1 and pin 2
    • Between pin 2 and pin 3
    • Between pin 5 and pin 6
    • Between pin 4 and pin 5
  4. Refer to the IAC Valve Terminal Identification table in Diagnostic Aids.

Are the resistances within the specified range?

21-23 ohms at 20°C (68°F)

Go to Step 7

Go to Step 10

7

  1. Connect the IAC valve electrical connector.
  2. Start the engine.
  3. Run the engine until a normal operating temperature is attained.
  4. Perform the scan tool Clear DTC Information function.
  5. Backprobe each IAC coil control circuit at the PCM with a DMM to connected ground.
  6. Observe the voltage display on the DMM for each IAC coil control circuit while increasing and decreasing the engine speed with the scan tool RPM Control function. Refer to Scan Tool Output Controls .

Does the voltage of each IAC coil control circuit switch from high to low with the increase and decrease in the engine speed?

--

Go to Step 9

Go to Step 8

8
  1. Inspect the IAC coil control circuits for a short or high resistance. Refer to Circuit Testing in Wiring Systems.
  2. Repair as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct a condition?

--

Go to Step 12

Go to Step 11

9
  1. Remove the IAC valve. Refer to Idle Air Control Valve Replacement .
  2. Inspect for the following conditions:
    3. • A leaking IAC valve gasket
    • A binding or stuck open IAC valve
    • An obstruction keeping the IAC pintle open
    • A damaged IAC pintle seat
  3. Repair the condition as necessary.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 10

10

Replace the IAC valve. Refer to Idle Air Control Valve Replacement .

Is the action complete?

--

Go to Step 12

--

11

Important: The replacement PCM must be programmed.

Replace the PCM. Refer to Powertrain Control Module Replacement .

Is the action complete?

--

Go to Step 12

--

12

  1. Turn OFF the ignition.
  2. Remove the DOME fuse for 30 seconds.
  3. Install the DOME fuse.
  4. Reset the radio clock time. Refer to Radio/Audio System Description and Operation in Entertainment.
  5. Start the engine.
  6. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or until the DTC P0507 diagnostic test has run.

Does the DTC run and pass?

--

Go to Step 13

Go to Step 2

13

With a scan tool, observe the stored information, Capture Info.

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

--

Go to Diagnostic Trouble Code (DTC) List

System OK