What Does P0639 Mean?
The PCM has detected that the electronic throttle actuator on Bank 2 is not responding within the expected range or performance parameters. This applies to vehicles with dual throttle bodies (typically V-configuration engines with individual throttle bodies per bank). The Bank 2 throttle plate position deviates from the commanded position.
Safety Warning
Vehicle will likely enter reduced power/limp mode. Bank 2 cylinders may receive incorrect airflow. Drive only to the nearest shop.
Common Causes
35%
Carbon buildup on Bank 2 throttle body restricting plate movement
30%
Faulty Bank 2 electronic throttle body motor or internal gear failure
20%
Bank 2 throttle position sensor providing inaccurate feedback
15%
Wiring issue between PCM and Bank 2 throttle body
Diagnostic Steps
1
Step 1: Monitor Bank 2 commanded vs. actual throttle position PIDs — deviation greater than 5% confirms the fault.
2
Step 2: Inspect the Bank 2 throttle body for carbon buildup and clean thoroughly with throttle body cleaner.
3
Step 3: Perform the throttle body relearn/calibration procedure specific to the Bank 2 throttle body.
4
Step 4: Measure Bank 2 throttle motor resistance and TPS voltage sweep — motor should be 1-10 ohms, TPS should sweep 0.5-4.5V smoothly.
5
Step 5: If cleaning and relearn do not resolve the issue and electrical tests fail, replace the Bank 2 throttle body assembly.
Estimated Repair Cost
$100 - $800
Parts + labor, varies by vehicle and location
The PCM has detected that the electronic throttle actuator on Bank 2 is not responding within the expected range or performance parameters. This applies to vehicles with dual throttle bodies (typically V-configuration engines with individual throttle bodies per bank). The Bank 2 throttle plate posit...
The most common cause of P0639 (Throttle Actuator Control Range/Performance (Bank 2)) is: Carbon buildup on Bank 2 throttle body restricting plate movement
Typical repair costs for P0639 range from $100 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle will likely enter reduced power/limp mode. Bank 2 cylinders may receive incorrect airflow. Drive only to the nearest shop.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0639 to identify the root cause.
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Quick Info
Category
Powertrain
System
Electronic Throttle Control
Difficulty
Type
Generic (SAE)
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