I'm currently trying to make some sort of rudimentary cruise control. I know some electronics however some of the engineering side i'm a little stuck on it. Please can someone knowledgable read what i'm thinking and give me some suggestions and/or confirm if i'm correct or not. I get really bad foot cramp while driving long distance so not having to keep my foot on the peddle would help massively.
The throttle peddle is attached to a cable which is attached to the Throttle Position Sensor (TPS). The TPS is essentially a variable resistor (rather potentiometer, POT) that is supplied with 5 volts [1] and connects directly to the engine management system.
a) Initial basic system to prove concept: connect a switch that bypasses the TPS to another POT mounted in the cabin on the dashboard, thus allowing the throttle to effectively be controlled via not the peddle but the dashboard POT
b) Second version: relay switched version with detection of brake and clutch movement to deactivate dashboard POT
c) Third version: feedback from speed to control second POT to control speed when going up and down hills.
Questions
q1) Is my understanding of the linkages to and from the TPS correct?
q2) Where is the TPS physically under the bonnet?
q3) What specification POT is the TPS effectively?
q4) What happens if BOTH the dash POT and TPS are disconnected at the same time (i.e. do I get an engine management system failure, engine cutoff, damage, require a trip to the garage to get the engine management system reset?). I don't have a engineer management diagnostic console so this is an important question.
q5) What is the wiring diagram for the TPS?
Many thanks,
Derek Bartram.
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[1] http://www.fixafordcar.co.uk/engine_management.htm
Throttle Position Sensor (TPS)
The throttle position sensor is a potentiometer which operated by the throttle plate. The throttle position sensor is supplied with a 5 volt reference voltage by the PCM. When the throttle plate is opened, a sliding contact moves over a resistance track, changing the output voltage. The output voltage is assigned to a corresponding throttle plate position by the powertrain control module.
The throttle peddle is attached to a cable which is attached to the Throttle Position Sensor (TPS). The TPS is essentially a variable resistor (rather potentiometer, POT) that is supplied with 5 volts [1] and connects directly to the engine management system.
a) Initial basic system to prove concept: connect a switch that bypasses the TPS to another POT mounted in the cabin on the dashboard, thus allowing the throttle to effectively be controlled via not the peddle but the dashboard POT
b) Second version: relay switched version with detection of brake and clutch movement to deactivate dashboard POT
c) Third version: feedback from speed to control second POT to control speed when going up and down hills.
Questions
q1) Is my understanding of the linkages to and from the TPS correct?
q2) Where is the TPS physically under the bonnet?
q3) What specification POT is the TPS effectively?
q4) What happens if BOTH the dash POT and TPS are disconnected at the same time (i.e. do I get an engine management system failure, engine cutoff, damage, require a trip to the garage to get the engine management system reset?). I don't have a engineer management diagnostic console so this is an important question.
q5) What is the wiring diagram for the TPS?
Many thanks,
Derek Bartram.
-----------------------
[1] http://www.fixafordcar.co.uk/engine_management.htm
Throttle Position Sensor (TPS)
The throttle position sensor is a potentiometer which operated by the throttle plate. The throttle position sensor is supplied with a 5 volt reference voltage by the PCM. When the throttle plate is opened, a sliding contact moves over a resistance track, changing the output voltage. The output voltage is assigned to a corresponding throttle plate position by the powertrain control module.
