U212U Diagnostic Trouble Code

U212U 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 U212U diagnostic trouble code may include:

The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Faulty PCM
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
Rich or lean exhaust

Possible Causes :

The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Fuel with a large percentage of sulfur will clog the DPF quickly
An air leak forward of the DPF will change the sensor readings resulting in the code

Repair Processes :

Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed. 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.

Process Tips

Diagnostic trouble code U212U 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 U212U.

Fortunately, U212U is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U212U Trouble Code For Specific Cars

U212U Alpine V6 Air Bag Passenger Inflator Circuit
U212U Kia Rondo Secondary Air Injection System Switching Valve A Circuit Malfunction
U212U Daihatsu Freeclimber Gear Shift position short to battery
U212U Reliant Rebel Gate Select Actuator Circuit Low
U212U Mercedes-benz 420 Air Bag Safing Sensor Output Circuit Failure
U212U Chevrolet Caprice 8 Driver Power Window One Touch Window Relay Circuit Failure
U212U Rover Montego Ignition Coil Primary Circuit Failure