DTC P0506: Idle Control System RPM Lower Than Expected
NOTE:
If DTC P0511 is stored at the same time as DTC P0506, troubleshoot DTC P0511 first, then recheck for DTC P0506.
- Start the engine. Hold the engine at 3,000 RPM with no load (in Park or neutral) until the radiator fan comes on, then let it idle.
- Check the engine speed at idle with no-load conditions: headlights, blower fan, rear window defogger, radiator fan, and air conditioner off.
Is the engine running at 650+/-50 RPM?
- YES - Intermittent failure, system is OK at this time.
- NO - Go to step 3.
- Turn the ignition switch OFF.
- Disconnect the idle air control (IAC) valve 3P connector.
- Start the engine, and let it idle.
- Check the engine speed at idle with no-load conditions: headlights, blower fan, rear window defogger, radiator fan, and air conditioner off.
Does the engine speed increase or fluctuate?
- YES - Check the idle speed with a different load condition (electrical, A/C, gear position, P/S, etc.) (see Idle Speed Inspection ). If it's out of specification, replace the IAC valve (see THROTTLE BODY DISASSEMBLY/REASSEMBLY ).
- NO - Replace the IAC valve (see THROTTLE BODY DISASSEMBLY/REASSEMBLY ).