Engine speed sensor Implausible frequency
|  | Description
|  | Effects on the driving operation
|  | Possible causes
|  | Installation point of the speed sensor
|  | Place of action
|  | Instruction
|  | Setting conditions of the event
|  | Test conditions of the event
|  | Troubleshooting
|  | Final function check
|  | See also:
Description Implausible frequency Effects on the driving operation Hard shifts Driving in reverse gear is not possible or restricted. If the output sensor is also defective, only limp-home mode available No torque limitation relative to the engine speed Engine torque reduction is limited. The characteristic curve of the auxiliaries is not considered. The engine speed and values derived from it are incorrectly set in the CAN communication. Possible causes Implausible speed ratios between engine output speed and transmission output speed have been measured in the mechanical gear which are not possible due to the transmission ratio. Attention: The output speed sensor can also be the cause of this fault! Possible causes: The sensors are installed in the wrong position, defect of the speed sensors, no correct adhesion of the disks. Installation point of the speed sensor Place of action Transmission mechanics Engine speed sensor Transmission output speed sensor Turbine speed sensor Instruction Check all frequency transmitters for correct signal generation and correct installation (distance to the measurement gear). Setting conditions of the event No description available. Test conditions of the event No description available. Troubleshooting Replace the sensor with a new one and make a test drive to check if the fault has been eliminated. Check the installation of the speed sensor. Check the size of the air gap between sensor and measuring gear.
Sensor | Distance of sensor to measuring gear
N1 (engine) | 1.1 (± 0.3 mm)
N2 (transmission output) | 2.5 mm (± 0.3 mm)
N3 (turbine) | 1.1 (± 0.3 mm)
The distance can be measured as follows: Dismantle the sensor. Make sure that a tooth of the measuring gear comes to a halt in the center of the sensor axis. Measure the distance from the assembly surface to the tooth using a depth gauge. Subtract the sensor length from the measured value (assembly surface to sensor tip). If the fault could not be removed, the measuring gear is possibly defective. After having contacted the Voith customer service, replace the measuring gear with a new one. 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)