CAN 2 - Hardware Occurrence of a bus-warning state
|  | Description
|  | Effects on the driving operation
|  | Possible causes
|  | Connector pin assignment of transmission control unit
|  | Place of action
|  | Troubleshooting
|  | Setting conditions of the event
|  | Test conditions of the event
|  | Final function check
|  | See also:
Description Communication on the CAN bus is disturbed due to ´CAN warning´ conditions. A ´CAN warning´ is caused by a CAN controller receiving too many invalid data. A CAN controller in warning condition can still read data from the CAN bus but it can no longer send data. The warning condition is automatically cancelled once the CAN controller has received a certain percentage of valid data. Effects on the driving operation The transmission function is limited due to sporadic unavailability of various functions such as engine torque reduction, retarder function. Vehicle does not drive or only with restrictions. Possible causes This error message is generated by the hardware and occurs when the control unit has problems sending. The fault is caused by: * Faulty terminating resistors on the CAN bus. * Loose contact in the CAN lines. * Too high contact resistances in the CAN cabling. * Other control units are not ready to receive. * Transmission control unit alone on the CAN bus. 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
Place of action CAN bus 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 ( ~ 60 ohms). Check cabling. * Install/repair terminating resistors on the CAN bus. * Check CAN wiring and plug-in connectors for loose contact and contact resistances. Setting conditions of the event No description available. Test conditions of the event No description available. 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)