U0204 Diagnostic Trouble Code

U0204 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 U0204 diagnostic trouble code may include:

Blown fuse (if applicable)
Engine surge
Reduction in engine performance, especially at low RPM levels
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

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)
Dirty air cleaner element Damaged DPF

Repair Processes :

It should be pretty close to battery voltage (12 volts). If not, then this is the circuit that has the problem. 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. 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.

Process Tips

Diagnostic trouble code U0204 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 U0204.

Fortunately, U0204 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U0204 Trouble Code For Specific Cars

U0204 Toyota Matrix Optical Sensor System Failure
U0204 Alfa Romeo Gta Air Assisted Injector Control Range/Performance
U0204 Merkur Xr Air Suspension RF Air Spring Solenoid Output Circuit Short To Battery
U0204 Holden Td Power Window LR Motor Circuit Short To Ground
U0204 Opel Diplomat Dim Panel Decrease Input Circuit Failure
U0204 Suzuki Sc Mirror Driver Left Circuit Failure
U0204 Bugatti Id 90 Cylinder #6 High To Low Side Open