U1820 Diagnostic Trouble Code

U1820 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 U1820 diagnostic trouble code may include:

Faulty PCM
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Poor acceleration
Hesitation upon acceleration

Possible Causes :

Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.

Repair Processes :

Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. 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 U1820 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 U1820.

Fortunately, U1820 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U1820 Trouble Code For Specific Cars

U1820 Scion Fr-s Injection Pump Fuel Metering Control "B" Low (Cam/Rotor/Injector)
U1820 Fiat 12 Hp Kickdown Relay Hold Circuit Fault
U1820 Lancia Scorpion SSPOD Open Circuit or Closed Circuit Fault
U1820 Nissan Axy Climate Control Air Temperature Internal Sensor Motor Circuit Short To Ground
U1820 Berkeley B Booster Pedal Force switch circuit Failure
U1820 Citroen Gs Fuel Level Sensor Circuit Range/Performance
U1820 Moretti La Cita Blower Fan Speed Circuit Range/Performance