How the throttle switch works
Here you will find useful basic information and important tips relating to the throttle valve switch in vehicles.
Important safety note
The following technical information and practical tips have been compiled by HELLA in order to provide professional support to vehicle workshops in their day-to-day work. The information provided on this website is intended for use by suitably qualified personnel only.
Throttle valve switches determine the throttle valve position. They are mounted directly on the throttle valve shaft. The various switch positions are transmitted to the engine management control unit and assist in the calculation of the required fuel quantity.
The throttle valve switch houses two switches which are actuated using a switching mechanism. The two switches give the engine management control unit information on the engine operating states "idle" and "full load" to ensure the necessary fuel quantity is accurately calculated.
A faulty throttle valve switch can cause the following:
The causes of a faulty throttle valve switch could be:
The following test steps should be considered during troubleshooting:
Check the throttle valve switch for correct mounting
Check whether the switching mechanism is actuated by the throttle valve shaft (with the engine switched off, move the throttle valve from the idle limit stop to the full-load limit stop and listen to hear whether the switches are actuated)
Check the plug connection to ensure it is fitted correctly and for any contamination