Why can't the central instrument or combination instrument work normally?
BMW's entertainment system adopts the most ring structure. What needs to be specially mentioned is that the F-series and E-Series entertainment systems should be changed. The gateway zgw and combination instrument are also included in the entertainment system. The information transmission between the gateway and other components also adopts the optical fiber mode. The communication between the E-Series vehicle host and the gateway adopts the kcan bus mode to transmit data, The host also plays the role of entertainment system gateway, so even if the most optical fiber system is open circuit, the host and CID can work normally. If one part of F series has a problem, the whole system will be paralyzed. Corresponding to this car failure should be one of the components can not work normally.
Why the starter is not running, based on the current situation, the possibility of problems in the starter itself is very small. In order to ensure that there must be no problem, the control line of the starter was measured. As a result, no signal came out when the start button was pressed.
What conditions should be met before the starter can run?
1、 Key data legitimacy (anti theft can be removed)
2、 Effective transmission of brake signal
3、 The transmission is in N or P gear
Refer to the circuit diagram (as shown in the figure), the startup is controlled by CAS (convenient access and startup control module), then these three signals must be truly and effectively transmitted to CAS, it will control the operation of the starter. The light can be turned on normally and the brake light can also be turned on, indicating that the CAS has received the two signals.