U0340 Diagnostic Trouble Code

U0340 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 U0340 diagnostic trouble code may include:

Vacuum leak on the engine
Reduction in engine performance, especially at low RPM levels
Engine surge
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.
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)

Repair Processes :

Find out what kind of system you have and verify that voltage to the fuel level sensor is present at the fuel pump wiring harness. Now, clear the codes and test-drive the vehicle to see if the code is reset.

Process Tips

Diagnostic trouble code U0340 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 U0340.

Fortunately, U0340 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U0340 Trouble Code For Specific Cars

U0340 Citroen Activa Flash To Pass Switch Circuit Short To Ground
U0340 Citroen 11 Fan Relay (High) Circuit Malfunction
U0340 Mercedes B Class ABS Hydraulic Pump Motor Circuit Open
U0340 Honda Concerto Pressure Control Solenoid Intermittent
U0340 Chevrolet Corsa Driver Side Crash Sensor Communication Fault (Non SCP)
U0340 Morris Ital Brake Pressure Switch Mechanical Failure
U0340 Citroen C4 Aircross FTS High - Fuel Pump Temperature Sensor High