U20D9 Diagnostic Trouble Code

U20D9 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 U20D9 diagnostic trouble code may include:

Malfunction Indicator Lamp (MIL) illuminated
Carbon Buildup on O2 Sensor
Poor fuel economy
Engine surge

Possible Causes :

Rusty exhaust systems, cracked exhaust manifolds or damaged or missing gaskets or donuts will cause air leaks.
An air leak forward of the DPF will change the sensor readings resulting in the code
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.

Repair Processes :

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. You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data. Look for damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code U20D9 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 U20D9.

Fortunately, U20D9 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U20D9 Trouble Code For Specific Cars

U20D9 Reliant Sst Gate Select Position Circuit Low
U20D9 Smart Fortwo Lamp Air Bag Warning Indicator Circuit Open
U20D9 Fiat 500 Lamp Air Bag Warning Indicator Circuit Open
U20D9 Overland 42 Double Locking Door Motor Frozen
U20D9 Lexus Rx 300 TFT Sensor In Range Failure High
U20D9 Maserati Royale Transmission Fluid Temperature Sensor Circuit Range/Performance
U20D9 Mitsubishi Sup B Camshaft Position - Timing Over-Advanced or System Performance (Bank 2)