P0507

P0507-IDLE SPEED PERFORMANCE HIGHER THAN EXPECTED

For complete wiring diagrams refer to Diagrams/Electrical.


Theory of Operation

The objective of the Idle Speed Rationality monitor is to evaluate the ability of the idle speed control system to achieve and maintain a steady idle, by monitoring engine RPM during idle. If engine RPM is not within a calibrated deadband of target idle speed, a timer is started. If the timer reaches a maximum threshold without any sign of the RPM trending towards control, a fault is generated.

- When Monitored:

With the engine idling in drive, the brake applied, MAF below 250 mg/tdc, air temp above -17.8° C (0° F), coolant temp is above 70° C (158° F), Evap purge below 100% duty cycle, and no VSS, MAF/MAP, ECT, TPS, ETC, CKP Sensor, fuel system, or injector DTCs present.

- Set Condition:

Engine speed is 175 RPM or more above target idle speed for 30 seconds. Two Trip Fault. Three good trips to turn off the MIL.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

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 and allow it to reach operating temperature.

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.

With a scan tool, select View DTCs.

Is the status Active for this DTC?

Yes

- Go to 2

No

- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. Checking for an Intermittent DTC

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

- Repair as necessary.
- Perform the PCM Verification Test. PCM Verification Test

No

- Go to 3

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

- Repair as necessary.
- Perform the PCM Verification Test. PCM Verification Test

No

- Go to 4

4. ENGINE 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 engine for external vacuum leaks.
Inspect the engine for internal leaks.

Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test. PCM Verification Test

No

- Go to 5

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 the throttle cable between the Accelerator Pedal and Throttle

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

- Repair as necessary.
- Perform the PCM Verification Test. PCM Verification Test

No

- Go to 6

6. POWERTRAIN CONTROL MODULE (PCM)

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the throttle body and the Powertrain Control Module (PCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Refer to any Technical Service Bulletins that may apply.

Were any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test. PCM Verification Test

No

- Replace and program the Powertrain Control Module (PCM).
- Perform the PCM Verification Test. PCM Verification Test