What Does P2129 Mean?
The PCM has detected an intermittent fault in the throttle/pedal position sensor 'E' circuit. This indicates sporadic signal loss, voltage fluctuations, or momentary opens/shorts that don't persist long enough to set hard fault codes.
Common Causes
40%
Loose or corroded connections at APP sensor connector
30%
Intermittent open or short in wiring harness
20%
Failing accelerator pedal position sensor with intermittent internal fault
10%
Vibration-induced connection issues or damaged wire routing
Diagnostic Steps
1
Step 1: Thoroughly inspect APP sensor connector for loose terminals, corrosion, or moisture; clean and apply dielectric grease
2
Step 2: Wiggle test all wiring while monitoring sensor voltage on scan tool; watch for dropouts or spikes
3
Step 3: Check wiring harness routing for areas where it may contact hot or moving components
4
Step 4: Monitor all APP sensor circuits simultaneously during test drive, looking for correlation issues
5
Step 5: If no wiring issues found, replace APP sensor as internal intermittent faults are difficult to diagnose
Estimated Repair Cost
$150 - $600
Parts + labor, varies by vehicle and location
The PCM has detected an intermittent fault in the throttle/pedal position sensor 'E' circuit. This indicates sporadic signal loss, voltage fluctuations, or momentary opens/shorts that don't persist long enough to set hard fault codes.
The most common cause of P2129 (Throttle/Pedal Position Sensor/Switch "E" Circuit Intermittent) is: Loose or corroded connections at APP sensor connector
Typical repair costs for P2129 range from $150 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may experience sudden limp mode activation or throttle response issues without warning. Could create dangerous situations.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P2129 to identify the root cause.
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Quick Info
Category
Powertrain
System
Electronic Throttle Control
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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