CAN gear range selector E330 CAN bus off
|  | Description
|  | Effects on the driving operation
|  | Possible causes
|  | Connection of the CAN gear selector switch
|  | Connector pin assignment of transmission control unit
|  | Connector pin assignment of CAN gear selector switch
|  | Place of action
|  | Instruction
|  | Setting conditions of the event
|  | Test conditions of the event
|  | Troubleshooting
|  | Final function check
|  | See also:
Description Communication on the CAN bus fails due to CAN ´bus off´ conditions. A CAN ´bus off´ condition occurs if the error counter of a CAN controller exceeds 255. The CAN controller is disconnected from the CAN bus using an internal logic function and does no longer participate in the bus activities. The control unit that belongs to the CAN controller can no longer receive or send CAN messages. Effects on the driving operation Driving is not possible or restricted. Transmission shifts sporadically to neutral. Lighting of the gear range selector becomes dark. Possible causes Short-circuit between CAN-H and CAN-L or short-circuit of one or both lines to ground or to supply voltage. Another CAN bus node sends with an incorrect bit rate (250kbit/s are expected). Other bus node is defective. Defect CAN transceiver in the gear range selector controller Defect CAN transceiver in E330. Connection of the CAN gear selector switch The jumpers on the transmission control unit (D13 to D17) and on the CAN gear range selector (6 to 7) activate the integrated CAN terminating resistors since the transmission control unit and the CAN gear range selector are usually the only CAN bus nodes at CAN2. The CAN bus must always be wired with the terminating resistors on both sides. Connector pin assignment of transmission control unit
Pin | Stecker A | Stecker B | Stecker C | Stecker D
1 | SHIELD | EK | FLEXI-1 | -BATT
2 | TIM+ | DK | --- | IGN
3 | TIM- | SK | FLEXI-3 | FLEXI-11
4 | N1+ | RBK | FLEXI-4 | K-LINE
5 | N1- | TB | FLEXI-5 | CAN1-H
6 | N2+ | --- | FLEXI-6 | CAN1-H
7 | N2- | RBG | FLEXI-7 | CAN-SHLD
8 | N3+ | PB | FLEXI-8 | CAN1-L
9 | N3- | WR | FLEXI-9 | CAN1-L
10 | --- | WP | FLEXI-10 | CAN2-H
11 | --- | --- | FLEXO-2H | CAN2-H
12 | EKM | FLEXI-12 | FLEXO-4H | CAN2-L
13 | DKM | S-GND | FLEXO-3H | CAN2-L
14 | SKM | OIL-LVL | FLEXO-5L | CAN1-R
15 | PBM | T-SUMP | --- | ---
16 | TBM | --- | --- | FLEXO-1L
17 | RBKM | T-CONV | --- | CAN2-R
18 | MVM-GND | MV-GND | --- | +BATT
Connector pin assignment of CAN gear selector switch
Pin | Name | Pin | Name | Pin | Name
1 | IGN | 6 | CAN-H | 11 | FLEXI-4
2 | -BATT | 7 | CAN-R | 12 | FLEXI-5
3 | CAN-L | 8 | FLEXI-1 | 13 | FLEXI-6
4 | CAN-L | 9 | FLEXI-2 | 14 | FLEXO-1H
5 | CAN-H | 10 | FLEXI-3 |  |
Place of action No description available. Instruction Check the cabling (cable break, loose contact, high contact resistance). Measure between CAN-H and CAN-L: the resistance must be approx. 60 ohms – install / repair bus terminating resistor if necessary. Measure between CAN-H and CAN-L (the resistance must be approx. 60 ohms) – check / repair cabling if necessary. Measure CAN-H and CAN-L to ground: the resistance must be significantly larger than 1kohm – check / repair cabling if necessary. Measure CAN-H and CAN-L to supply voltage: the resistance must be significantly larger than 1kohm – check / repair cabling if necessary. Check whether correct dataset in control unit (correct CAN protocol); if not, replace dataset, disconnect the other bus nodes one after the other and check whether this eliminates the fault – replace defective control unit or contact manufacturer. Disconnect and check one bus node after the other and see whether the fault is thus eliminated – replace the defective / faulted control unit. Replace control unit of gear range selector. Setting conditions of the event No description available. Test conditions of the event No description available. Troubleshooting
|  | NOTE The following service work may only be performed by persons who are authorised by the vehicle manufacturer: Loading software and/or datasets into the transmission control unit. Service work at vehicle components which are not included in the VOITH delivery.
Measure resistance between CAN-H and CAN-L. The nominal value is 60 Ω. Measure resistance between CAN-H and ground. The resistance must lie well above 1 kΩ. Measure resistance between CAN-L and ground. The resistance must lie well above 1 kΩ. Measure the resistance between CAN-H and supply voltage. The resistance must lie well above 1 kΩ. Measure the resistance between CAN-L and supply voltage. The resistance must lie well above 1 kΩ. Check whether the correct dataset is active in the transmission control unit. Check whether the correct CAN protocol is active. Disconnect the other control units from the CAN bus one after the other and check whether this eliminates the fault. Replace CAN gear range selector. Final function check If the defective component cannot be clearly identified, you should try to reproduce the fault: Reinstall the component in the vehicle. Test the function. After the fault has been eliminated, the following steps have to be carried out: Conduct a test drive with function check. Read out the fault memory. Check the transmission for leaks. Perform a final visual inspection. These steps are necessary to ensure the entire vehicle functions. See also:
|  | Aftersales service index
© by Voith Turbo GmbH & Co. KG, S. Brunnengräber send remarks to stefan.brunnengraeber@voith.com (documentation department)