Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2008 Kia Optima EX, 2.4 3FACTORY OEM SERVICE PROCEDURE
Etc (Electronic Throttle Control) System: Fail-Safe
FAIL-SAFE CHART
| ITEMS | FAIL-SAFE | |
|---|---|---|
| Throttle motor | Throttle valve stuck at 5° | |
| TPS 1, TPS 2 signal | TPS1 fault | Replace it with TPS2 |
| TPS2 fault | Replace it with TPS1 | |
| TPS1,2 fault | Throttle valve stuck at 5° | |
| APS 1, APS 2 signal | APS1 fault | Replace it with APS2 |
| APS2 fault | Replace it with APS1 | |
| APS1,2 fault | Throttle valve stuck at 5° | |
When throttle valve is stuck at 5° engine speed is limited at below 1500 RPM and vehicle speed at maximum 40-50 km/h (25-31 MPH).
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.