U1133 Diagnostic Trouble Code

U1133 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 U1133 diagnostic trouble code may include:

Malfunction Indicator Lamp (MIL) illuminated
Carbon Buildup on O2 Sensor
Poor fuel economy
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

Possible Causes :

Fuel with a large percentage of sulfur will clog the DPF quickly
The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.

Repair Processes :

Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. If the engine displays a miss and there wasn't a code, determine which cylinder is misfiring. If the exhaust manifold is visible, spay or pour a small amount of water on each cylinder exhaust port. Water will evaporate immediately on good cylinders and slowly on the missing cylinder. If this can't be accomplished pull the plugs and check the condition. Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble.

Process Tips

Diagnostic trouble code U1133 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 U1133.

Fortunately, U1133 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U1133 Trouble Code For Specific Cars

U1133 Mercury Grand Air Suspension LR Corner Down Timeout
U1133 Jeep Grand Cherokee Seat Driver Rear Up Switch Circuit Short To Battery
U1133 Rolls-royce Silver Ghost IAT - B Sensor Intermittent
U1133 Chevrolet Zafira Engine Coolant Temperature Circuit Range/Performance Problem
U1133 Ferrari 159 Injector Control Pressure Not Detected During Crank
U1133 Lancia Medusa Split Air #1 Circuit Malfunction
U1133 Toyota Sera Park/Neutral Switch Circuit Open