What Does P1638 Mean?
The electronic throttle control system detected that the throttle blade became temporarily stuck or restricted from moving to the commanded position. This was a transient event that has since cleared.
Common Causes
40%
Carbon buildup on throttle blade or bore causing temporary sticking
20%
Ice formation in throttle body during cold weather operation
15%
Foreign object temporarily lodged in throttle body
15%
Throttle body motor wearing internally causing intermittent binding
10%
Lubrication or debris from intake system contaminating throttle blade
Diagnostic Steps
1
Step 1: Remove intake duct and visually inspect throttle body for carbon deposits, contamination, or foreign objects
2
Step 2: Manually check throttle blade movement with ignition off - should move freely without binding
3
Step 3: Clean throttle body thoroughly with appropriate cleaner, removing all carbon deposits from blade and bore
4
Step 4: Use scan tool to command throttle blade open/closed while observing smooth operation and proper response
5
Step 5: Perform throttle adaptation procedure, clear codes, and monitor during extended test drive to verify repair
Estimated Repair Cost
$100 - $500
Parts + labor, varies by vehicle and location
The electronic throttle control system detected that the throttle blade became temporarily stuck or restricted from moving to the commanded position. This was a transient event that has since cleared.
The most common cause of P1638 (Throttle Valve Position Control; Throttle Stuck Temporarily) is: Carbon buildup on throttle blade or bore causing temporary sticking
Typical repair costs for P1638 range from $100 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Temporary throttle sticking can cause unexpected acceleration or deceleration, creating hazardous driving conditions.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1638 to identify the root cause.
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Quick Info
Category
Powertrain
System
Electronic Throttle Control System
Difficulty
Type
Manufacturer
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