U0124 Diagnostic Trouble Code

U0124 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 U0124 diagnostic trouble code may include:

Poor acceleration
Cherry red hot catalytic converter
Possible spark knock (detonation / pre-ignition)
Engine surge

Possible Causes :

Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)
Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.

Repair Processes :

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

Process Tips

Diagnostic trouble code U0124 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 U0124.

Fortunately, U0124 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U0124 Trouble Code For Specific Cars

U0124 Citroen C4 Picasso Ii Fuel Composition Sensor Circuit Low Input
U0124 Lotus 79 Torque Converter/Brake Switch B Circuit Low
U0124 Ginetta G32 Optical Sensor System Failure
U0124 Packard Patrician Driver Door Handle Circuit Failure
U0124 Aston Martin 2-litre Air Suspension RF Height Sensor Circuit Failure
U0124 Toyota Ractis Park Brake Switch # 2 Applied Circuit Short to Gnd
U0124 Vauxhall Vectra C Pressure Control Solenoid C Stuck On