U3656 Diagnostic Trouble Code

U3656 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 U3656 diagnostic trouble code may include:

Vacuum leak on the engine
Reduction in engine performance, especially at low RPM levels
Engine surge
Rich or lean exhaust

Possible Causes :

The Mass Airflow sensor will also cause this problem. Mass Airflow circuit malfunction.
Fuel with a large percentage of sulfur will clog the DPF quickly
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)

Repair Processes :

Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. Look at the plug wires to make sure they are not burnt or laying on the exhaust. If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for.

Process Tips

Diagnostic trouble code U3656 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 U3656.

Fortunately, U3656 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U3656 Trouble Code For Specific Cars

U3656 Aberdonia 16 A/C Refrigerant Pressure Sensor Circuit Range/Performance
U3656 Abarth Ot 1000 A/C Evaporator Air Temperature Circuit Range/Performance
U3656 Chevrolet Four Ninety Dual Alternator Battery Lamp Circuit Malfunction
U3656 Great Wall Steed 5 Passenger Seat Occupant Detection Circuit Short To Battery
U3656 Mercedes S 63 Air Bag Crash Sensor #1 Feed/Return Circuit Open
U3656 Pegaso Z103 Driver's Seat Seatback Autoglide Forward Switch Circuit Short to Ground
U3656 Dkw Reichklasse Ignition Coil - Cylinder 1 - Early Activation Fault