P0507

Diagnostic Chart:

Wiring Diagram:

Circuit Description

The Idle Speed Control (ISC) motor opens and closes the throttle valve according to signals from the Powertrain Control Module (PCM). When a condition arises which demands a higher idle speed, the PCM will send a signal to the ISC motor which will extend the plunger of the ISC motor, thus opening the throttle plates and increasing the idle speed. When the higher idle speed is no longer needed, the PCM will reverse the polarity to the ISC motor which will cause the throttle plates to close and decrease the idle speed.

Conditions for Running the DTC

^ Closed Throttle Position (CTP) switch ON.

^ Battery voltage is greater than 12 volts.

^ Engine coolant temperature is greater than 80°C (175°F).

^ Intake air temperature is between -10°C (14°F) and 50°C (122°F).

^ Fuel level 1/4 or more.

^ Barometric Pressure is at least 560 mm Hg (75 kPa).

^ Engine running for 5 minutes or more.

Conditions for Setting the DTC

^ Engine idle speed is greater than the target idle speed by 200 RPM or more.

Action Taken When the DTC Sets

^ The Malfunction Indicator Lamp (MIL) will illuminate after two consecutive ignition cycles in which the diagnostic runs with the fault active.

^ The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame buffer.

Conditions for Clearing the MIL/DTC

^ The MIL will turn OFF after three consecutively passing cycles without a fault present.

^ A History DTC will clear after 40 consecutive warm-up cycles without a fault.

^ DTCs can be cleared by using a scan tool or by disconnecting the PCM battery feed.

Diagnostic Aids

Check for any of the following conditions:

^ If a DTC P0510 is set, refer to the DTC P0510 first. P0510

^ A stuck or binding throttle plate may cause a DTC P0507 to set. Check the throttle plate for smooth and even movement.

^ Check the EVAP canister purge control system for proper operation.

^ Check the Throttle Position (TP) sensor for accurate throttle position readings.

^ Check the adjustment of the accelerator cable. Refer to Fuel Delivery and Air Induction / Throttle Cable/Linkage / Adjustments. Adjustments

^ A poor connection at the PCM. Inspect the harness connectors for backed out terminal, improper mating, broken locks, improperly formed or damaged terminals, and a poor terminal to wire connection.

^ A damaged wiring harness. Inspect the wiring harness for damage and repair as necessary.

^ Inspect the engine for a large vacuum leak. Check for a condition that could cause a large vacuum leak, such as a incorrectly installed or faulty crankcase ventilation valve or a brake booster hose disconnected.

^ Check the ISC Duty cycle parameter on a scan tool. The scan tool parameter should read 20-40% duty cycle, at normal operating temperatures.

If a DTC P0507 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining vehicle operating conditions when the DTC was first set.

If any wiring repairs need to be made, Refer to Repair Procedures in Electrical Diagrams.

Test Description

The numbers below refer to the step numbers in the Diagnostic Table.

1. The Powertrain OBD System Check 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.

3. Determine if the fault is present now.

6. This step checks the ignition feed to the ISC relay for an open circuit.

9. This step check for an open or short in the ISC motor control circuit.

10. This step checks the functionality of the ISC motor and the ISC motor control circuits.