U1905 Diagnostic Trouble Code

U1905 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 U1905 diagnostic trouble code may include:

Poor acceleration
Cherry red hot catalytic converter
Possible spark knock (detonation / pre-ignition)
Rich or lean exhaust

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.
A plugged converter will cause of host of driveability problems as well as set this code. A severely plugged converter will result in the inability to increase rpm when under load. Look for a code such as P0421 -- catalytic converter efficiency below threshold if the converter indicating a faulty converter.

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. Oxygen sensors signal the engine management computer the amount of oxygen present in the exhaust, which is used in determining and controlling the fuel ratio.

Process Tips

Diagnostic trouble code U1905 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 U1905.

Fortunately, U1905 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U1905 Trouble Code For Specific Cars

U1905 Singer Super Invalid Steering Wheel Angle Sensor ID
U1905 Edsel Ranger Injection Control Pressure Out Of Range High
U1905 Rover 220 IDM Input Circuit Malfunction/ Ignition Coil Control Circuit High Voltage
U1905 Suzuki X90 Mirror Driver Vertical Feedback Potentiometer Circuit Short to Ground
U1905 Honda City Pressure Control Solenoid C Stuck On
U1905 Austin 8 Autolamp Delay Circuit Short To Ground
U1905 Abarth Lancia A/C Compressor Temperature Sensor Malfunction