P1259 APP Sensor Correlation Fault
The P1259 code indicates a correlation error between the accelerator pedal position (APP) sensor circuits, specifically between the PDS2 (Pedal Position Sensor 2) signal circuit and the LPDS (Low Pedal Position Sensor) reference circuit. The powertrain control module (PCM) detects that the voltage on the PDS2 circuit exceeds the calibrated limit relative to the LPDS circuit, pointing to a failure in the electronic throttle control (ETC) system's safety redundancy.
01. Most Common Causes
- Faulty or internally worn accelerator pedal position sensor
- Short to battery voltage in the PDS2 signal circuit
- Open or short to ground in the LPDS reference circuit
- Loose, corroded, or damaged connectors at the APP sensor
- Internal PCM failure (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Poor throttle response or hesitation
- Engine may not start or stalls
03. Step-by-Step Diagnosis
Scan for codes and verify P1259 is present; check for related codes.
Inspect APP sensor connector for corrosion, damage, or loose pins.
Test PDS2 signal voltage at sensor and PCM; compare to LPDS reference.
Check for shorts to power or ground in PDS2 and LPDS circuits.
If wiring and connector are good, replace the APP sensor assembly.
If code persists, test PCM output signals or consider PCM replacement.
1. Frequently Asked Questions
Is it safe to drive?▼
No, this is a critical fault. The vehicle may enter limp mode or stall unexpectedly, posing a safety risk. Have it towed to a repair shop.
How much does it cost to fix?▼
Typically $200 to $600, including parts (APP sensor $50–$200) and labor (1–2 hours). PCM replacement can exceed $1,000.