audi a3 temperature gauge problem

[stock211]

hi i recently fitted a new engine coolant temperature sensor as my gauge wasn't working. cleared the fault code with vcds lite and all was well for a week, now the gauge has stopped working again,did another scan and vcds is reading the temperature fine and isn't throwing any codes so dont think the sensor is bad.have any of you guy and gals got any idea's as what could be wrong? cheers in advance

 

[<tuffty/>]

thermostat?... please define 'not working'

<tuffty/>

 

[stock211]

worked fine for a week sitting at 90, all of a sudden needle not moving at all. but on scan temperature rising as normal ???

 

[<tuffty/>]

Which temperature are you logging? the CTS has two sensors... one for the ECU and one for the dash... you will need to go to the instruments module to log the sensor for the dash...

Is the CTS an OE one? have seen GSF and ECP pattern parts fail fairly quickly in the past..

<tuffty/>

 

[stock211]

the sensor i replaced is the blue four pin one, i thought 2 wires were for the ecu and the other 2 were for the gauge ?? the temperature reading on vcds were on 17 instrument >measuring blocks >group 3 i think. is this right or i'm i looking in the wrong place..bit of a newbie where vcds is concerned

 

[<tuffty/>]

Blue 4 pin? is yours an AGU?

Sounds like the right group in VCDS... if its rising to 90 and the dash needle isn't moving then sounds like the dash is faulty... not sure if something like will throw a fault code... have you check the fault codes in the instruments module?

<tuffty/>

 

[stock211]

engine a AGN,thats what confusing me no fault codes in instruments..think i'll have to try another sensor.think it was a pattern part even tho it cost 15 quid...

 

[stock211]

what i need to know is there a way to test the 4 pins on the sensor?with a multi meter? and if so how would i go about this

 

[<tuffty/>]

If the ECU is seeing temps and the instruments are seeing temps then the issue is the clocks mate

<tuffty/>

 

[stock211]

thanks for the advice,would the clocks just die after fitting a new sensor,could it be a fuse or a short in the wiring just want to be sure before buying new dials:thumbsup

 

[stock211]

just a quick update...with the help from youtube and a multimeter How to test a Coolant Temperature Sensor - YouTube i was able to test the ECT sensor, and found out it was bad. lesson learned fit oem parts not cheap ones from ebay. as the cheap one only lasted a week, we now have a working temperature gauge sat at 90.....very nice

 

[@udi A3]

Another way is to check output displays in instruments with vcds. not always conclusive but does diagnose a faulty needle motor