DTC P0506: Idle Control System RPM Lower Than Expected

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

Turn the ignition switch ON (II).
Clear the DTC with the HDS.
Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on.
Check for these conditions in the DATA LIST with the HDS:
- Engine coolant temperature above 156°F (70°C)
- Intake air temperature above 32°F (0°C)
- Vehicle speed is 0 mph (0 km/h)
- Fuel trim between 0.73 and 1.47
- FSS is CLOSED.
Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS.
Does the screen indicate FAILED ?
1. YES - Go to step 6.
2. NO - If the screen indicates PASSED, go to step 15. If the screen indicates EXECUTING, keep the condition continually until a result comes on. If the screen indicates OUT OF CONDITION, go to step 4 and recheck.
Remove the intake air duct from the throttle body.
Check for dirt, carbon and damage at the throttle bore.
Is there dirt, carbon or damage in the throttle bore?
1. YES - If there is dirt or carbon, clean the throttle body (see THROTTLE BODY TEST ), and also check for damage at the air cleaner element (seeAIR CLEANER ELEMENT INSPECTION/REPLACEMENT ), then go to step 9. If there is damage in the throttle bore, go to step 8.
2. NO - Check the A/C system or power steering system, then go to step 1 and recheck.
Replace the throttle body (see THROTTLE BODY REMOVAL/INSTALLATION ).
Reset the PCM with the HDS.
Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
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 for these conditions in the DATA LIST with the HDS:
- Engine coolant temperature above 156°F (70°C)
- Intake air temperature above 32°F (0°C)
- Vehicle speed is 0 mph (0 km/h)
- Fuel trim between 0.73 and 1.47
- FSS is CLOSED
Check for Temporary DTCs or DTCs with the HDS.
Are any Temporary DTCs or DTCs indicated?
1. YES - If DTC P0506 is indicated, go to step 1 and recheck. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.
2. NO - Go to step 14.
Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
1. YES - Troubleshooting is complete.
2. NO - If the screen indicates FAILED, go to step 1 and recheck. If the screen indicates EXECUTING, keep the condition continually until a result comes on. If the screen indicates OUT OF CONDITION, go to step 12 and recheck.
Remove the intake air duct from the throttle body.
Check for dirt, carbon and damage at the throttle bore.
Is there dirt, carbon or damage in the throttle bore?
1. YES - If there is dirt or carbon, clean the throttle body (see THROTTLE BODY REMOVAL/INSTALLATION ), and also check for damage at the air cleaner element (see AIR CLEANER ELEMENT INSPECTION/REPLACEMENT ), then go to step 9. If there is damage in the throttle bore, go to step 8.
2. NO - Go to step 17.
Recheck with different load condition (turn on the headlights, blower motor, rear window defogger and/or A/C, changing the shift lever position, etc.)
Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS.
Does the screen indicate PASSED?
1. YES - Troubleshooting is complete.
2. NO - If the screen indicates FAILED, check the A/C system and/or power steering system, then go to step 1 and recheck. If the screen indicates EXECUTING, keep the condition continually until a result comes on. If the screen indicates OUT OF CONDITION, go to step 17 and recheck.