What Does P1577 Mean?
The PCM has detected a mismatch between the two accelerator pedal position sensors. Modern drive-by-wire systems use dual redundant sensors for safety, and this code indicates they are not reporting consistent values.
Safety Warning
Vehicle may enter limp mode with reduced power or fail to accelerate properly. This is a critical safety system - do not drive extensively until repaired.
Common Causes
45%
Failed accelerator pedal position sensor assembly with one sensor out of calibration
25%
Corroded or damaged connector at accelerator pedal sensor
15%
Wiring issue causing voltage drop or intermittent signal on one sensor circuit
10%
Mechanical binding or contamination in pedal assembly affecting sensor readings
5%
PCM requiring calibration or software update
Diagnostic Steps
1
Step 1: Use scan tool to monitor both accelerator pedal position sensor voltages in live data - they should track proportionally
2
Step 2: Slowly depress accelerator pedal while watching both sensor values - look for one sensor lagging, jumping, or reading incorrectly
3
Step 3: Inspect accelerator pedal sensor connector for corrosion, bent pins, or moisture damage
4
Step 4: Check reference voltage supply to both sensors (typically 5V) and ground circuit integrity
5
Step 5: If sensors show proper voltage but disagree, replace accelerator pedal sensor assembly
Estimated Repair Cost
$150 - $600
Parts + labor, varies by vehicle and location
The PCM has detected a mismatch between the two accelerator pedal position sensors. Modern drive-by-wire systems use dual redundant sensors for safety, and this code indicates they are not reporting consistent values.
The most common cause of P1577 (Pedal Position Sensor Disagreement btwn Sensors) is: Failed accelerator pedal position sensor assembly with one sensor out of calibration
Typical repair costs for P1577 range from $150 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may enter limp mode with reduced power or fail to accelerate properly. This is a critical safety system - do not drive extensively until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1577 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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