U2406 Diagnostic Trouble Code

U2406 is a kind of OBD-II Diagnostic U-Network Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a U2406 diagnostic trouble code may include:

Poor acceleration
Cherry red hot catalytic converter
Possible spark knock (detonation / pre-ignition)
Rich or lean exhaust

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.
A plugged converter will cause of host of driveability problems as well as set this code. A severely plugged converter will result in the inability to increase rpm when under load. Look for a code such as P0421 -- catalytic converter efficiency below threshold if the converter indicating a faulty converter.

Repair Processes :

Use the DVOM to test resistance and continuity on all system circuits if actuator and sensor resistance levels are in compliance with manufacturer's specifications. 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.

Process Tips

Diagnostic trouble code U2406 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 U2406.

Fortunately, U2406 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U2406 Trouble Code For Specific Cars

U2406 Mercedes-benz 220 Air Bag Passenger Circuit Failure
U2406 Yamaha Ox99
U2406 Kia K2700 Seat Switch Reference Voltage Positive Common Supply Voltage Fault
U2406 Mercury Tracer Air Suspension Reservoir Solenoid Circuit Failure
U2406 Peugeot Touareg Engine Oil Pressure Sensor/Switch Range/Performance
U2406 Subaru B9 Left Front Center Sensor Circuit Failure
U2406 Chevrolet Camaro 6 Driver Power Window Motor Circuit Short To Battery