U1118 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.

U1118 Code Symptoms :

While fuel economy was increased, acceleration was seriously compromised, and the loss of engine vacuum led to a dangerous loss of braking assist when the U1118 code system was in four-cylinder mode. In addition to these issues, while the company proposed a hydraulically controlled system that could be switched from within the car, the version they implemented had to be manually changed in the engine compartment using hand tools.

Diagnosis And Repairing U1118

U1118 the main thing to check is to verify the operation of the VCT solenoid. You're looking for a sticking or stuck VCt solenoid valve caused by contamination. Refer to vehicle specific repair manual to perform component tests for the VCT unit.

How to fix U1118 code ?

• Faulty Air Flow Meter
• Camshaft Position Sensor harness is open or shorted
• Incorrect fuel filler cap used
• Incorrect fuel filler cap used

Circuit High Input codes like U1118 are mostly caused by defective alternators that develop excessive voltages, although there may be other causes as well, such as short circuits that 'leak' current into a particular system from other, unrelated systems that work on higher voltages. Note that in the case of short circuits that leak power into a control circuit, there is likely to be other, seemingly unrelated trouble codes present along with the code(s) being investigated. Diagnosing a 'high input' code will always involve a thorough testing of the charging system as a first step, followed by measures to isolate the system from all other possible sources of power during resistance, continuity, and reference voltage tests.