U0122 Railton 20 Diagnostic Trouble Code

U0122 Railton 20 code definition:
U0122 is a kind of OBD-II Diagnostic U-Network Diagnostic Trouble Code for Railton 20.

U0122 Railton 20 shows up when there's an electrical problem that causes the fuel volume regulator to malfunction and open. It's quite an unusual problem and likely intermittent. Other symptoms that may indicate this problem are when the Check Engine Light illuminates and when there is a visible lack of engine power.

Symptoms

Symptoms of a U0122 Railton 20 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
  • Rich or lean exhaust
Place of U0122 in engine

Possible Causes :

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

Common Misdiagnoses

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

Repair Processes :

If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for. With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground. Look at the plug wires to make sure they are not burnt or laying on the exhaust.

Process Tips

Diagnostic trouble code U0122 Railton 20 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 U0122 Railton 20.

Fortunately, U0122 Railton 20 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

Diagnostic Trouble Code look-up and check engine light code viewer.

Copyright 2020 - https://diagnosticTrouble.com

Small Logo