What Does P1634 Mean?
The PCM has detected that the voltage signal from accelerator pedal position sensor 2 is above the acceptable maximum threshold. This indicates either a sensor circuit fault, internal sensor failure, or short to voltage in the redundant APP sensor circuit.
Safety Warning
Vehicle may enter limp mode with severely limited throttle response or refuse to accelerate, creating hazardous conditions in traffic.
Common Causes
35%
Accelerator pedal position sensor 2 internal failure or short to voltage
30%
Damaged wiring or connector pins in APP sensor 2 circuit shorted to 5V reference or battery voltage
20%
Corroded or damaged APP sensor connector causing intermittent high resistance
10%
Chafed wiring harness rubbing against metal creating short to power
5%
PCM internal fault in sensor 2 signal processing circuit
Diagnostic Steps
1
Step 1: Inspect APP sensor connector and wiring harness for damage, corrosion, or signs of chafing
2
Step 2: Measure voltage at APP sensor 2 signal wire with key on, engine off - should read approximately 0.5-1.0V at rest, not above 4.8V
3
Step 3: Check for short to voltage in APP sensor 2 signal circuit using voltmeter with sensor disconnected
4
Step 4: Monitor live data for both APP sensor 1 and 2 voltages while slowly depressing pedal - sensor 2 should track proportionally with sensor 1
5
Step 5: If circuits test normal, replace accelerator pedal position sensor assembly and retest
Estimated Repair Cost
$200 - $600
Parts + labor, varies by vehicle and location
The PCM has detected that the voltage signal from accelerator pedal position sensor 2 is above the acceptable maximum threshold. This indicates either a sensor circuit fault, internal sensor failure, or short to voltage in the redundant APP sensor circuit.
The most common cause of P1634 (Accelerator Pedal Position Sensor 2 Signal Too High) is: Accelerator pedal position sensor 2 internal failure or short to voltage
Typical repair costs for P1634 range from $200 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may enter limp mode with severely limited throttle response or refuse to accelerate, creating hazardous conditions in traffic.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1634 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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