Where is the Throttle / Speed sensor on 172 ?

[finch wxm]

My car wont start, diagnostics are saying speed sensor / throtlle sensor .

anyone point me in the right direction

 

[mr.pink87]

throttle sensor (tps) is located in the throttle body, speed sensor (tdc sensor!?) is located below the thermostat housing pointing at the flywheel. starting issues are often tdc sensor/-plug related!

 

[finch wxm]

the plugs are brand new, the car has been stationary the last year while i i do work on it. it was fine 2 days ago and started. now i have a electrical faullt light on the dash. on my diagnostic machine it says PO500 VEHICLE SPEED SENSOR A .

would the TDC sensor cause it not to start then ?

 

[mr.pink87]

i did not mean the spark plugs, i meant the plug of the tdc. tdc is often causing starting problems as said above. check the fastchip.nl hp for a manual for the 172, the tdc resistance is stated there.

 

[Fred@BTM]

which 172 is it?

 

[finch wxm]

Hi fred its just a standard 53 plate iceburg silver 172 . Its got electrical fault on dash and my diagnostic just gives speed sensor A fault so not totally sure if the means the TDC sensor, i have looked at the TDC sensor and its the old type with the black plug so i recko its the original one. Ive had the car almost a year now and it hasnt moved of the drive as ive been doing bits and bobs which have needed doing !

ive ordered a new TDC sensor so hopefully this may solve the problem but im not sure. my friends diagnostic machine gave afew more codes saying throtlle open etc

 

[finch wxm]

just removed the TDC sensor and cleaned up the connector block and hey presto its started up ! electrical fault light has gone but service light is on which um assuming is because its sensing the TDC sensor is not functioning correctly as its doesnt like low revs and stalls.

New sensor will be here either tommorow or monday so one step closer to get it ready for an MOT and track bound !