1. What is P1125?

P1125 is a Diagnostic Trouble Code indicating Throttle/Pedal Position Sensor 'A' Circuit Low Input. It measures throttle or pedal position and sends a voltage (0.5–4.5V) to the ECM for engine load calculation. Low input (<0.2V) triggers limp mode to protect the engine.

2. Common Causes in Ford F-150 & Volkswagen Golf

• Dirty Throttle Body (Ford F-150 3.5L EcoBoost) — Deposits block sensor signal. Clean throttle body using UR1000 Throttle Test.
• Faulty Wiring (VW Golf 1.4L TSI) — Connector corrosion or chafed wiring reduces voltage. Inspect and repair per UR1000 Wiring Test.
• Sensor Failure (VW Golf GTI 2.0T) — Low input voltage detected by UR1000 indicates sensor replacement needed (#06L907386C).
• Aftermarket Pedal/Throttle Modifications — Misaligned or incompatible components cause erratic voltage, triggering P1125.

3. Key Symptoms

• Check Engine Light + Reduced Engine Power warning
• Slow acceleration or hesitation on throttle input
• Rough idle and inconsistent engine response
• Increased fuel consumption due to ECM default mapping

4. Models Prone to P1125

5. Diagnostic Steps with ICARZONE UR1000

• Full system scan for P1125 and related codes (P0120–P0125)
• Live voltage monitoring of throttle/pedal sensor using UR1000
• Throttle response test to check sensor signal increase with pedal movement
• Wiring continuity and resistance test
• TSB lookup and model-specific calibration steps

6. Fixes & Execution

• Clean dirty throttle body (Ford F-150 3.5L EcoBoost)
• Repair wiring and connectors (VW Golf 1.4L TSI)
• Replace faulty throttle/pedal sensor (VW Golf GTI)
• Run UR1000 calibration and relearn procedures post-repair

7. Repair Costs & Safety Tips

• DIY diagnosis with UR1000: $0
• Throttle Sensor replacement: $90–$170
• Throttle body cleaning kit: $20–$35
• Professional repair: $200–$400

• Always disconnect the battery before sensor removal
• Use manufacturer-approved cleaning solutions
• After repair, clear codes with UR1000 and perform road test

8. Preventive Maintenance

• Inspect throttle body every 20,000 miles; clean as needed
• Check wiring and connectors periodically
• Use OEM parts for replacements to prevent P1125 recurrence
• Run UR1000 sensor checks quarterly for early detection

9. Frequently Asked Questions

10. Summary

P1125 (Throttle/Pedal Position Sensor 'A' Circuit Low) affects Ford F-150 and Volkswagen Golf models. Causes include dirty throttle body, wiring issues, or sensor failure. Using ICARZONE UR1000 ensures accurate diagnosis, calibration, and TSB-compliant fixes. Preventive checks maintain engine performance and efficiency.