U1748 Diagnostic Trouble Code

U1748 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 U1748 diagnostic trouble code may include:

Engine surge
Blown fuse (if applicable)
Lack of power
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

Rough running engine due to misfiring plugs. Many engines have misfire codes to indicate the cylinder effected, such as P0307 for number 7.
Rarely - faulty Powertrain Control Module (PCM-programming required after replacement)
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.

Repair Processes :

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. With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground. Pack the connector cavity with dielectric silicone compound (same stuff they use for light bulb sockets and spark plug wires) and reassemble.

Process Tips

Diagnostic trouble code U1748 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 U1748.

Fortunately, U1748 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

U1748 Trouble Code For Specific Cars

U1748 Alfa Romeo 2000 ABS Pump Switch Circuit Failure
U1748 Renault 5 Gear Lever X Position Circuit Intermittent
U1748 Ford Five Hundred Mirror Driver Down Circuit Failure
U1748 Volvo 780 SCP (J1850) Invalid or Missing Data for Engine Air Intake
U1748 De Tomaso Longchamp Hydraulic Base Brake Failure
U1748 Saturn Lw Immobilizer to PCM Signal Error
U1748 Volkswagen Caddy 3 RESCU/VEMS Input Circuit Short to Battery