U3644 Diagnostic Trouble Code

U3644 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 U3644 diagnostic trouble code may include:

Misfire
Misfire
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Reduction in engine performance, especially at low RPM levels

Possible Causes :

An air leak forward of the DPF will change the sensor readings resulting in the code
Rusty exhaust systems, cracked exhaust manifolds or damaged or missing gaskets or donuts will cause air leaks.
Fuel with a large percentage of sulfur will clog the DPF quickly

Repair Processes :

Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. Pull the connectors apart and carefully look at the terminals (the metal parts) inside the connectors. 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. 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.

Process Tips

Diagnostic trouble code U3644 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 U3644.

Fortunately, U3644 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U3644 Trouble Code For Specific Cars

U3644 Fiat Armadillo Lamp Headlamp High-Beam Circuit Open
U3644 Astra Utility Air Temperature External Sensor Circuit Short To Battery
U3644 Mitsubishi Asx Audio Navigation Mute Input Ckt Failure
U3644 Mercedes Cl 500 ABS Inlet Valve Coil RF Circuit Failure
U3644 Dodge Mirada Ignition Retard Request Circuit Fault
U3644 Austin 16 Audio Steering Wheel Control Unit is Not Responding
U3644 Tvr Se Power Limit Shutdown Fault