DTC P0507: Idle Control System RPM Higher Than Expected (2004-2006 models)

NOTE:

If DTC P0511 is stored at the same time as DTC P0507, troubleshoot DTC P0511 first, then recheck for DTC P0507.
Before you troubleshoot, record all freeze data and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
Check the engine speed at idle without load condition: headlights, blower fan, rear defogger, and air conditioner off.
Is the engine running at 900+/- 50 RPM?
1. YES -Intermittent failure, system is OK at this time.
2. NO -Go to step 3.
Turn the ignition switch OFF.
Disconnect the intake air duct from the throttle body.
Start the engine, and let it idle.
Put your fingers on the lower port (A) in the throttle body (B).

Fig 1: Identifying Lower Port
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Does the engine speed drop below 900 RPM?
1. YES -Check the idle speed under different load conditions (electrical, A/C, gear position, P/S, etc.) (see IDLE SPEED ADJUSTMENT ). If it's out of specification, replace the IAC valve.
2. NO -Check for vacuum leaks at these parts:
  - PCV valve
  - PCV hose
  - EVAP canister purge valve
  - Intake manifold
  - Throttle body
  - Brake booster hose