Transmission output speed sensor Insufficient signal quality
|  | 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 Poor signal quality The measured pulse durations and/or periods vary more than allowed (no continuous signal available). Effects on the driving operation No retarder operation Driving in reverse gear not possible or limited. No ANS-function Driving in 1st gear only. Higher gears at very high engine speed only (engine protection). If a substitute function is available, the fault may only cause poor gearshifts and hard retarder activation. If the engine speed sensor is simultaneously defective, only limp-home mode is available. Possible causes Extreme torsional vibrations. Installation position of sensor is not correct or the sensor is loose. The pulse-generator wheel has damages that may cause signal disturbance. The sensor malfunctions. Installation point of the speed sensor Place of action n2 speed sensor Instruction Check the installation position of the sensor (distance, tolerance position). Make sure that the sensor sits tightly. Ensure the correct function of the sensor. Check the pulse-generator wheel for damage. 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)