P0639
Throttle Actuator Control Range/Performance Bank 2
Throttle actuator control
Generic OBD-II
High
What it means
P0639 means the bank-2 electronic throttle isn't moving to the position the ECM commanded. On engines with two throttle bodies, this often forces reduced-power or limp mode to keep things safe. The usual causes are a failing throttle body/actuator, carbon buildup binding the plate, or a wiring fault — so cleaning and testing come before replacement.
High
Can I keep driving? Drive cautiously — a throttle-control fault usually triggers reduced-power/limp mode; the car still moves but may be sluggish, so get it fixed soon.
Common symptoms
What you'll notice
- Reduced power or limp mode
- Rough idle, surging, or stalling
- Hesitation or poor acceleration
- Check-engine light on
Common causes
Most likely first
- Faulty bank-2 throttle body / throttle actuator motorLikely
- Carbon buildup binding the throttle plateCommon
- Wiring or connector fault at the throttle bodyCommon
- Poor ground or power feed to the throttle actuatorLess often
- Faulty engine control module (ECM), rareLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and check for related throttle/pedal codes.
- Inspect and clean the bank-2 throttle body if carbon is binding the plate.
- Check the throttle body connector and wiring for damage or corrosion.
- Test the throttle actuator and position sensors, then perform a throttle relearn.
- Replace the throttle body if it fails to track commands. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0639?+
The car may drop into limp mode with limited power. Short, gentle driving is usually fine, but sudden power loss makes it worth fixing promptly.
Can I just clear P0639?+
It returns quickly if the throttle body still can't track the commanded position. A cleaning or throttle relearn sometimes helps, but a failed actuator needs replacement.
Related codes
Often seen with P0639
Read & clear P0639 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX