The 2021 Genesis G90 should idle with flagship-sedan refinement—nearly imperceptible vibration befitting its luxury status. When engine vibration develops at idle accompanied by P0507 (Idle Air Control System RPM Higher Than Expected), the investigation focuses on idle speed control.
Understanding P0507
Code P0507 indicates the engine is idling faster than the computer expects. While "higher idle" might seem opposite to a vibration complaint, the ECU's attempts to control abnormal idle conditions can cause rough running and vibration.
How P0507 Causes Vibration
When the idle control system fights against vacuum leaks or other factors affecting idle speed, the resulting fluctuations cause vibration. The engine may surge between too-high and too-low RPM as the computer overcorrects.
Symptoms to Document
- Vibration through steering wheel and seats at idle
- Check engine light with P0507
- Idle RPM fluctuating or higher than normal
- Possible surging at stop lights
- Vibration may reduce when in gear
Common Causes
Vacuum Leaks
Air entering the intake unmeasured raises idle speed. The ECU tries to compensate, causing hunting and vibration.
Throttle Body Issues
Carbon deposits or electronic throttle body malfunctions affect idle air control.
IAC Valve Problems
The idle air control valve or electronic throttle body actuator can malfunction.
PCV System Leaks
Crankcase ventilation issues create vacuum leaks affecting idle.
Repair Costs
| Repair | Parts | Labor | Total |
|---|---|---|---|
| Vacuum leak repair | $25-$150 | $100-$250 | $125-$400 |
| Throttle body cleaning | $15-$50 | $75-$150 | $90-$200 |
| Throttle body replacement | $300-$600 | $150-$300 | $450-$900 |
| PCV system repair | $50-$150 | $100-$200 | $150-$350 |