P1678 BMW Fault Code

Description:

The Throttle Position sensor signals the Engine Control Module as to the current position of the engine throttle valve.
The current throttle valve opening is based on the driver's input from the gas pedal.

The ECM uses the information from this sensor to help calculate fuel delivery and spark timing.

P1678 Code Symptoms :

The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. P1678 code had an elaborate diagnostics procedure, including showing engine trouble codes on the air conditionning display. However, the system was troublesome, misunderstood by customers, and a rash of unpredictable failures led to the technology being quickly retired.

Diagnosis And Repairing P1678

P1678 OBD 2 code on vehicles with electronically controlled automatic transmissions, the 3-4 shift solenoid is responsible for actuating the hydraulic circuits to activate clutches or bands that change gears inside the automatic transmission.

How to fix P1678 code ?

• Faulty Air Flow Meter
• Camshaft advance mechanism binding (VCT unit)
• Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
• Variable Valve Timing (VVT) circuit is open or shorted

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code P1678, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code P1678 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.