9/12/19

2020 Mercedes Benz Truck ML 350 4MATIC (164.186) V6-3.5L (272.967) WWW.EBAAUTOPARTS.COM Page 3216

2020 Mercedes Benz Truck ML 350 4MATIC (164.186) V6-3.5L (272.967) WWW.EBAAUTOPARTS.COM Page 3216



incomplete.The control unit then switches off for a short time from CAN bus.



- For example:CAN controller: CAN bus OFF



Functional CAN fault



- A functional CAN fault code is set because of an implausible CAN input signal.The cause of this is not the CAN networking, but the



transmitter control unit or its sensors.



- For example:CAN signal 'A' from control unit B is implausible.



Notes on CAN faults that cannot be read out as fault codes.Bus wake-up event



- An event that wakes up the bus without reason is designated a bus wake-up event.



- The cause of this is not the CAN networking, but the transmitter control unit or its sensors.



- Further possible causes of fault:



- Magnetic fields caused by nearby high-voltage installations, railroad installations or power plants.



- Magnetic fields can radiate on to lines and control units in rare cases and cause undefined behavior in the control units.



- The special tool 'Star Diagnosis CANtool' can be used to log bus wake-up events, bus keepawake events and other signals.



Bus keepawake event



- When a control unit keeps communication on the bus awake without reason, this is designated a bus keepawake event.



- The cause of this is not the CAN networking, but the transmitter control unit or its sensors.



- Further possible causes of fault:



- Magnetic fields caused by nearby high-voltage installations, railroad installations or power plants.



- Magnetic fields can radiate on to lines and control units in rare cases and cause undefined behavior in the control units.



- The special tool 'Star Diagnosis CANtool' can be used to log bus wake-up events, bus keepawake events and other signals.



1.1.2. No further information available.



1.1.3. General CAN fundamentals



Test 1.1.3.1: Low-Speed CAN (83,3 kBit/s)



Test 1.1.3.2: High-Speed CAN (125 kBit/s , 500 kBit/s)



1.1.3.1. Low-Speed CAN (83,3 kBit/s)



General CAN fundamentals



Low-Speed CAN (83,3 kBit/s)



- 83,3 kBit/s : For example:Interior CAN busSeries 211



- This CAN bus enables single-wire mode.



- 'Single-wire mode' means that fault-free communication between the control units is still possible even if one of the two CAN lines fails.



- This CAN bus does not require external terminating resistors.



Legend and description for figure 1CAN-H: CAN bus HighCAN-L: CAN bus LowECU 1 ... n: Control unit 1 ... nLegend and description for figure



2U 1: Specification approx. 3,6 voltsU 2: Specification approx. 0 voltsU 3: Specification approx. 2,5 voltsU 4: Specification approx. 1,4 voltsU 5:



Specification approx. 5 voltsContinue with button F2