C0840 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.

C0840 Code Symptoms :

The scent may C0840 signal oil or coolant leaking from their normally closed-loop systems, or it may indicate dangerous exhaust gases invading your car's interior. Car and truck exhaust contains toxic gases such C0840, so if the inside of your car as if you were standing behind your car, get out and get it fixed.
Fight the urge to take a little nap first. So sleepy. That's the carbon monoxide talking, friends. At least open a window on your way to the shop.

Diagnosis And Repairing C0840

C0840 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 C0840 code ?

• Faulty Air Flow Meter
• Air fuel ratio (A/F) Sensor 1 Bank 1 harness is open or shorted
• Faulty Variable Camshaft Timing (VCT) position solenoid
• Dirty Oil

Circuit High Input codes like C0840 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.