U2020 Diagnostic Trouble Code

U2020 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 U2020 diagnostic trouble code may include:

Hesitation upon acceleration
Excessive exhaust leak
Rich or lean exhaust
Lack of power

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.
Some aftermarket accessories and performance modifications

Repair Processes :

Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble. 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 U2020 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 U2020.

Fortunately, U2020 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U2020 Trouble Code For Specific Cars

U2020 Bugatti Type 18 Cylinder #8 High To Low Side Short
U2020 Ferrari 288 Input-shaft-speed input circuit failure
U2020 Edsel Ranger Injection Control Pressure Out Of Range High
U2020 Mercedes Slk 250 Air Bag Diagnostic Monitor Ground Circuit Short To Battery
U2020 Toyota Crown O2 Sensor Circuit Slow Response (Bank 1 Sensor 3)
U2020 Fiat 505 Lamp Backup Switch Input Circuit Failure
U2020 Allard Gt Air Bag Crash Sensors #1 / #2 Circuit Short To Ground