U0066 Diagnostic Trouble Code

U0066 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 U0066 diagnostic trouble code may include:

Lack of power
Faulty O2 Sensor
Poor acceleration
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)
Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.

Repair Processes :

Once located, visually inspect the connectors and wiring. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. 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.

Process Tips

Diagnostic trouble code U0066 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 U0066.

Fortunately, U0066 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U0066 Trouble Code For Specific Cars

U0066 Wolseley Hornet SCP (J1850) Invalid or Missing Data for Suspension
U0066 Mazda Persona
U0066 Volkswagen Scooter SBDS Interactive Codes
U0066 Frazer Nash Targa NVM Memory Failure
U0066 Daihatsu Applause Gear Shift Foward Actuator Circuit Low
U0066 Packard Executive Driver Door Ajar Circuit Short To Battery
U0066 Ford Fiesta MIL O/P Circuit Malfunction