After Warming Up, Idle Speed Is Below Specification Without Load (MIL Works OK, No DTCs Set)

After warming up, idle speed is below specification without load (MIL works OK, no DTCs set)

Diagnostic Procedure:

1. Troubleshoot the alternator FR signal circuit. Alternator FR Signal Circuit Troubleshooting

2. Do the carbon accumulation check. Testing and Inspection

3. Troubleshoot the PSP switch signal circuit. Component Tests and General Diagnostics

4. Troubleshoot the injector control module circuit. Injector Control Module Circuit Troubleshooting

5. Replace the fuel filter A element. Fuel Filter A Element Replacement

6. Replace the fuel filter B element. Fuel Filter B Element Replacement

7. Inspect the PCV valve. Testing and Inspection

Also check for:

- Clogged injector
- Incorrect valve adjustment