U3818 Diagnostic Trouble Code

U3818 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 U3818 diagnostic trouble code may include:

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

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.
Dirty air cleaner element Damaged DPF

Repair Processes :

Now, clear the codes and test-drive the vehicle to see if the code is reset. Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed. 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 U3818 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 U3818.

Fortunately, U3818 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U3818 Trouble Code For Specific Cars

U3818 Alfa Romeo 149 ABS Outlet Valve Coil RR Circuit Failure
U3818 Invicta 4.5-litre
U3818 Farboud Gts Injector Circuit Open / Shorted - Cylinder #3
U3818 Tatra T77 Mirror Switch Reference Voltage Negative Common Open Circuit
U3818 Zeta Saloon SCP (J1850) Lack of Acknowledgment for Primary Id
U3818 Edsel Villager Injection Control Pressure Out Of Range Low
U3818 Volvo 460