P1296 DTC and Fluctuating Temp guage

[iwaters]

Hi all,

A colleage of mine at work asked me to look at his car as his MIL light was on. I did a code scan and got P1296 Fault with mapped cooling system.

His temp gauge is struggling to reach 90 on the motorway and only starts to rise when he is in stationary traffic. My first thought was the thermstat was stuck open but he is also getting intermittent hot start issues so now I am thinking possibly a faulty CTS.

His heater is blowing out hot air.

The CTS is only £15 and easy to replace, whereas the thermostat looks like a bit more tricky.

He is happy to try and change the CTS but I wondered what people on here thought first.

Cheers

 

[Burnerman]

If the thermostat was working, the car should reach 90 deg no problem so I would say the stat is stuck open....but I'd also agree if there are starting issues then the CTS should be replaced too.
Is the car VAG?
John

 

[iwaters]

Cheers John.

Yes is it a VAG, sorry forgot to say what car it is. It's a Seat Leon Cupra R 2003.

I read the code with a basic scanner but I do have VAG-Com on a laptop, I can read the actual values from the CTS with that so should be able to see if it is fluctuating or reading incorrectly. Will try that tomorrow and then maybe change the CTS first and see what happens there, if that doesn't fix then go for the stat.

Thanks again

 

[Burnerman]

Good luck with it Ian and post back with the result!
John

 

[iwaters]

I connected VAG-Com/VCDS and set it to log and we went for a spin. The coolant temp was reading a plausable signal but it did seem to take ages to warm up. It also seemed to be reading quite high to begin with, around 32 degrees, when the outside temp is around 4/5 (had been left about 4 hours). When I checked my car the initial temp was about 21 degrees.

The temperature rose steadily although it did go down then back up again at one point.

I guess that test is inconclusive, I suggested putting some cardboard over the rad and taking it for a test but we are trying to fix this in our lunch hour in the office car park so instead we are just going to fit a new CTS, it is only £28 for a new sensor, sealing ring and retaining clip.

Hope that solves it

If not new T-Stat.

 

[Belle427]

a corsa i looked at a while ago had a cts which did the engine fuelling and the temperature gauge too, threw me for a while as i thought nearly all cars had seperate sensors

 

[iwaters]

Changed the CTS, was in a surprsing accessible place for a VAG car and the clip prised off with a screw driver.

Didn't fix the problem though

Must be the thermostat.