2012 Mitsubishi Pajero Sport P2138 Fault: Throttle Pedal Position Sensor Voltage Correlation Issue

Hello, I'm Sanjay Sharma from Chandigarh. I own a 2012 Mitsubishi Pajero Sport with a 2500cc diesel engine and manual transmission. For the past year, I've been experiencing a recurring issue where the accelerator pedal stops responding during driving, causing the engine to stall at around 1100 RPM—significantly higher than its normal idle of approximately 650 RPM. In neutral gear, the RPM may rise to 700–1200 after driving for about 50 to 800 kilometers. The problem typically reoccurs after a few hundred kilometers and only resolves temporarily when I disconnect the battery for 15 minutes. After that, the vehicle runs normally for another 500–800 km before the issue returns. I've already replaced several components including MAP sensor, MAF sensor, suction control valve, solenoid valve, and throttle body. All wiring has been checked and appears intact. The engine performance—such as fuel economy and pulling power—is otherwise excellent. However, this one critical issue poses a serious safety risk. The problem occurred during an overtaking maneuver at 120 km/h with another truck, which nearly led to a collision. It also happened on a hill climb, highlighting the danger of this fault. I am now seeking expert advice on how to properly diagnose and fix the P2138 code related to throttle pedal position sensor voltage correlation. Any guidance or technical solutions would be greatly appreciated. Thank you, Sanjay Sharma — Chandigarh, India.