U0125 Lexus Rx400h Diagnostic Trouble Code

U0125 Lexus Rx400h code definition:
U0125 is a kind of OBD-II Diagnostic U-Network Diagnostic Trouble Code for Lexus Rx400h.

U0125 Lexus Rx400h is defined as Camshaft Position Sensor A Circuit Low. This means the CMP (camshaft position) sensor circuit on engine bank 1 sends an irregular reading. This is because the barometric pressure sensor is part of the MAF sensor. Sometimes, the MAF's sensing wire can accumulate and get covered with dirt, dust and/or oil residue, which can also lead to the error code.

Symptoms

Symptoms of a U0125 Lexus Rx400h diagnostic trouble code may include:

Faulty O2 Sensor
Lack of power
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
Diminished fuel efficiency

Possible Causes :

A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Faulty IMRC actuator relay (if equipped)
Fuel with a large percentage of sulfur will clog the DPF quickly

Common Misdiagnoses

Vehicle Speed Output Circuit Problem
Cruise Control Servo Indicates Low Problem
A/C System High Pressure High Temperature Problem
PCM Stack Overrun Problem
Transmission Control Module Reprogrammable Memory Problem

Repair Processes :

If you find a related TSB, the information will often help in diagnosing the code in question as TSBs are crested from many thousands of repairs. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. Look at the plug wires to make sure they are not burnt or laying on the exhaust.

Process Tips

Diagnostic trouble code U0125 Lexus Rx400h is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before U0125 Lexus Rx400h.

Fortunately, U0125 Lexus Rx400h is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.