P0507-IDLE SPEED PERFORMANCE HIGHER THAN EXCEPTED

For a complete wiring diagram Refer to Section 8W.

Theory of Operation


The objective of the Idle “Speed Rationality is to monitor the ability to achieve and maintain a steady idle condition. The monitor will judge the functionality of the idle speed control system by monitoring RPM during idle. If RPM does not come within a calibrated deadband of target idle speed, a timer is started. If the timer reaches its maximum threshold without any sign of the RPM trending towards control, a soft failure is generated.


Possible Causes
AIR INDUCTION SYSTEM
PCV SYSTEM LEAKS OR RESTRICTIONS
ENGINE VACUUM LEAKS
THROTTLE BODY
PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).



Diagnostic Test

1. ACTIVE DTC

NOTE: If any other IAC Motor or Throttle Body DTCs are present, they must be diagnosed and repaired before continuing this test.


Start the engine.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.


Allow the engine to reach normal operating temperature.
With a scan tool, select View DTCs.

NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.



Is the DTC Active or Pending at this time?

Yes


No

2. AIR INDUCTION SYSTEM

Inspect the Air Induction System for the following problems.
Restrictions: Dirty Air Cleaner, Foreign material trapped in the air intake tube, etc.
Leaks: Air Intake tube connection, Air Cleaner housing, etc.

Were any problems found?

Yes


No

3. PCV SYSTEM

Inspect the PCV system for the following problems:
Restrictions - sticking valve, collapsed hoses or tubes, obstructed passages or ports, etc.
Leaks - cracked or damaged hoses or tubes, poor hose or tube connections, PCV valve stuck open, etc.

Were any problems found?

Yes


No

4. VACUUM LEAKS

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.


Start the engine.
Inspect the vehicle for external vacuum leaks.
Inspect the engine for internal leaks.

Were any vacuum leaks found?

Yes


No

5. THROTTLE BODY OPERATION / IAC MOTOR OPERATION

Inspect the throttle body for carbon build up, other restrictions, and a bent throttle plate using a straight edge.
If the throttle plate does not close entirely it may be bent and needs to be replaced.
Verify that the throttle cable between the Accelerator Pedal and APPS is not binding on ETC equipped vehicles.
Verify that the throttle cable between the Accelerator Pedal and Throttle Body is not binding on IAC equipped vehicles.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.


While the vehicle is running, lightly tap on ETC Motor or IAC Motor where applicable, with your hand, and listen for idle to raise.

Were any problems found or did the idle fluctuate while tapping on the ETC Motor or IAC Motor?

Yes


No

6. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.


Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes


No