Safety computer Defect of the internal safety switch
|  | Description
|  | Effects on the driving operation
|  | Possible causes
|  | Function of the safety computer
|  | Connector pin assignment of transmission control unit
|  | Pin assignment of transmission connector
|  | Place of action
|  | Instruction
|  | Setting conditions of the event
|  | Test conditions of the event
|  | Final function check
|  | See also:
Description The safety computer cannot close the internal safety switch. Effects on the driving operation Driving is not possible. Possible causes Open plug connection at cable 1. Defective plug connection at cable 1. Conducting connection of the common solenoid valve ground to another cable Conducting connection of the common solenoid valve ground to the transmission housing Conducting connection of the common solenoid valve ground to the vehicle chassis Interruption of the common solenoid valve ground Hardware defect of the safety switch Function of the safety computer The safety computer (S-CPU) monitors safety-relevant signals which the function computer (F-CPU) sends or receives. If the safety computer detects an inadmissible condition, it initiates a reset of the function computer. During that time, the transmission system is in a safe mode (neutral). Driving operation is only released if both the function computer AND the safety computer give their approval simultaneously. After the release the safety switch in the transmission control unit is closed and the ground of the solenoid valves is connected to the battery ground. Only then can the solenoid valves be activated and enable driving operation.
|  |  |  | monitored signal private CAN (gear selection)
S-CPU |  |  | N1 / N2 | monitored speeds
ALIVE | alive signal of F-CPU to S-CPU |  | MV | monitored actuation of all solenoid valves
COMM | communication between F-CPU and S-CPU |  | MV-GND | ground applied by safety switch
|  |  | -BATT | battery ground
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
Pin assignment of transmission connector
Pin | Name | Pin | Name | Pin | Name
1 | S-GND | 14 | RBK | 27 | EKM
2 | MV-GND | 15 | RBG | 28 | PBM
3 | MV-GND | 16 | TB | 29 | RBKM
4 | --- | 17 | WR | 30 | TBM
5 | T-CONV | 18 | --- | 31 | MVM-GND
6 | T-SUMP | 19 | --- | 32 | N1+
7 | OIL-LVL | 20 | --- | 33 | N1-
8 | P-DIFF | 21 | TIM- | 34 | N2+
9 | SK | 22 | TIM+ | 35 | N2-
10 | DK | 23 | --- | 36 | N3+
11 | EK | 24 | SHIELD | 37 | N3-
12 | PB | 25 | SKM |  |
13 | WP | 26 | DKM |  |
Place of action No description available. Instruction Check plug connections at cable 1. Should the fault not disappear, please contact the VOITH customer service. 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:
|  | Troubleshooting a short-circuit to ground
|  | Aftersales service index
© by Voith Turbo GmbH & Co. KG, S. Brunnengräber send remarks to stefan.brunnengraeber@voith.com (documentation department)