How is LIN bus fault diagnosed?
An easy way to check the LIN wiring is to unplug the slave module and check the ‘at rest’ voltage of the LIN wire. The master should send out the 7 to 12 volt reference. If the wiring to the multi-function switch checks out good, replace the switch. If the input shows to be correct, check the bussed outputs.
How does a LIN bus alternator work?
It supplies a current through a high side MOSFET to the excitation coil of the alternator and provides an internal freewheeling diode. It’s main functionality is to keep the battery at its nominal value, whatever the vehicle demand. The protection and diagnosis may be programmed using OTP (non-volatile Memory).
What should LIN bus voltage?
The LIN bus, and LIN transceivers, typically operate at voltages ranging from 9 V to 18 V, but some go up to 30 V, depending on the application; a typical vehicle is a 12-V battery system, but some larger vehicles go up to 24 V.
How do I check the signal on my Lin?
Check the output voltage from the slave device(s). With the slave device in question plugged in, disconnect the master control module and all other slave device(s) on the same LIN bus. At the master control module, check the output voltage from the slave device, which will be a steady 11–12 volts.
What is a LIN charge?
The LIN serial interface is used by the engine control unit (ECU) to transmit charging voltage set point from 10.7 V to 16 V, load response control ramp and cut-off speed and the field excitation limit. The voltage set-point command can also disable the field driver for a momentary no-output condition.
What is Lin voltage?
Why is the LIN signal on my bus not working?
Faults may be specific to a particular function, such as a non-operating window, or general, where all the functions on the bus are not working. Before condemning a device, use the scope to check that it has power, ground, and a present and correct LIN signal.
How is access to the LIN bus gained?
LIN-BUS circuit access can be gained at individually controlled components. As you can see from the example waveform, the LIN bus waveform is a square wave, representing the binary states in a serial data stream.
What should the voltage be for a battery charger?
With the battery warning light off, standard charging current as measured at the alternator B+ wire should be 10 amps or less, and charging voltage should range between 13.2 to 14.8 volts. With the headlamps on and the HVAC blower turned to “Hi” position, charging amperage should be 30 or more amps.
How to identify the LIN-bus circuit and connected components?
Use manufacturer’s data to identify the LIN-BUS circuit and connected components. Connect PicoScope Channel A into the LIN-BUS circuit and to a good earth. Minimize the help page. You will see that PicoScope has displayed an example waveform and is preset to capture your waveform.