Hello,
Backstory:
I've recently started getting occasional check engine during acceleration, but only when kickdown was pressed. OBD showed P0123 which is throttle sensor high input error. After cleaning up the error, check engine won't appear until I put gas pedal to the floor, but it's not guaranteed. I'd say it has 30% chance to trigger check engine. Car is CLK 270 CDI from 2004 and it has dull kickdown, but obviously clicking it still causes pedal to go slightly deeper and makes sensors to output a bit higher voltage.
Way the acceleration pedal sensors work is very nicely described in document below:
Now according to this document, assuming supply voltage 5V, maximum outputs of 2 sensors should be around 4.5V and 2.25V.
So I connected sensors to 5V power supply (4.89V measured) and in maximum lean I've got around 4.55V in first one and over 2.6V in the second one. Those values should be considered as estimations, as my jumper wire connections were far from perfect, and even a little yank caused voltage changes of 0.1V. And yet 2.6V seems pretty high for me and I wonder if that could exceed ECU limit and raise the check engine along with P0123 OBD error.
I couldn't find any specific info about expected values and limits for these voltages so if there is any expert, I would be pleased with some answers. I don't want to buy a new pedal just to check voltages on it
Backstory:
I've recently started getting occasional check engine during acceleration, but only when kickdown was pressed. OBD showed P0123 which is throttle sensor high input error. After cleaning up the error, check engine won't appear until I put gas pedal to the floor, but it's not guaranteed. I'd say it has 30% chance to trigger check engine. Car is CLK 270 CDI from 2004 and it has dull kickdown, but obviously clicking it still causes pedal to go slightly deeper and makes sensors to output a bit higher voltage.
Way the acceleration pedal sensors work is very nicely described in document below:
Now according to this document, assuming supply voltage 5V, maximum outputs of 2 sensors should be around 4.5V and 2.25V.
So I connected sensors to 5V power supply (4.89V measured) and in maximum lean I've got around 4.55V in first one and over 2.6V in the second one. Those values should be considered as estimations, as my jumper wire connections were far from perfect, and even a little yank caused voltage changes of 0.1V. And yet 2.6V seems pretty high for me and I wonder if that could exceed ECU limit and raise the check engine along with P0123 OBD error.
I couldn't find any specific info about expected values and limits for these voltages so if there is any expert, I would be pleased with some answers. I don't want to buy a new pedal just to check voltages on it
