B3986 BMW Fault Code

Description:

Vehicle Speed Sensor (VSS) Intermittent Indicates the powertrain control module (PCM) detected an error in the vehicle speed information. Vehicle speed data is received from either the vehicle speed sensor (VSS), transfer case speed sensor (TCSS), anti-lock brake system (ABS) control module, generic electronic module (GEM), or central timer module (CTM). This DTC is set the same way as B3986. However, it is intended to flash the transmission control indicator lamp (TCIL) for first time VSS circuit error/malfunctions. Refer to possible causes for B3986

B3986 Code Symptoms :

The scent may B3986 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 B3986, 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 B3986

B3986 OBD2 may also be triggered by faults earlier down the line. For example, a dirty MAF sensor might be causing the car to overcompensate in its fuel-trim adjustments. As a result, oxygen sensors are likely to report fuel mixture problems.

How to fix B3986 code ?

• Clogged or faulty fuel injector (s)
• Faulty Variable Camshaft Timing (VCT) position solenoid
• Fuel injectors may be faulty
• Fuel injectors may be faulty

As the engine heats up and combustion becomes easier and more complete, the PCM will command the idling control valve to increase the amount of air entering the engine to suit the changing conditions.

However, when the load on the engine changes, say, when some electrical consumers or other systems are either turned on or off, the PCM adapts the signal voltage to the idle control valve to ensure that the idling speed remains stable, and at the RPM specified by the manufacturer.