Ong2764

Hey guys I have this problem, my CEL comes on and stays on during High RPM use, around 6-7k. I took it into the dealership thinking it was my engine misfiring because I got the code read out. They told me that the engine was not misfiring, but it has something to do with the Coolant Temp Sensor. The mechanic told me that it was reading temperatures like -41 deg Celsius. The dealership said to bring it back this coming Wednesday when their mechanic who specialize on this stuff is working. My old problem is my working schedule and the dealership is an hour away from it.

My Question is how could I fix this? and is the problem the CTS? Would this problem also result in the loss of power? My car Idles fine, but its during the acceleration when you can feel the lost of power.

Oh also my car is a 2005 with 72k on the body and around 1k on the engine.

Best Regards,

80CUofRAWHP

If I'm not mistaken the CTS can throw it into limp mode if the ECU doesn't like the readings. I could be wrong but it could be your power loss.

Ong2764

Yeah that is what they were suggesting though. it just weird that the computer is throwing out misfire code, but they checked the coils,wires and plugs. Those were replaced around 60K miles.

Yeah the mechanic was saying something about the car putting itself on safe mode, which basically cuts the power.

Do you think replacing the CTS would fix this problem? and how hard is it to replace the CTS?

80CUofRAWHP

I've never replaced the CTS but I know the thermostat is kinda a bitch to get to and replace. Sounds like the tech is suggesting limp mode is the source of your misfire code and the cause of limp mode is the CTS. I know a few things about these mystery machines but I would wait for a more qualified member to suggest possible fixes before you go pulling stuff out.

Ong2764

Ahh ok, yeah, its weird that the mazda mechanic suggested that its safe to drive while under this condition.

Will def wait for someone else to reply and see if that is the source of the problem. Thanks again for the info man!

Karack

the CTS is a little bit of a pain to get to but definitely doable without all too much effort. a CTS fault will result in the ECU defaulting to a rich mixture state otherwise the car would be undrivable when cold, which will also likely result in a random power loss when warm as the adaptive cells haven't adjusted to lean the car out yet.

Ong2764

Oh ok, so I am hoping its nothing too big, I had one of my buddies look into it and he said that while driving it, he doesnt feel the misfires, but yet the CEL is spitting out code P0301. So hopefully the dealership could shed out some light and it wont be nothing more than the CTS unit needs to be replaced.

BigCajun

iTrader: (1)

Hello, I was driving mine after getting bad cat and misfire codes.
Seemed to be running fine at first, so I thought probably a bad sensor or something because it seemed to be running too good for all that and it could wait.
Got progressively worse at high RPM so I had to do something.
I had a bad cat and 1 bad coil & plug.
So it is possible to have misfires and not notice it.

Ong2764

Yeah I went to the dealership, and the mechanic said its not misfiring, but will wait for confirmation once their specialist takes a look at it. Thanks for your guys input!!!

9krpmrx8

iTrader: (46)

The CTS is like $20.00 at Autozone, etc., just replace it. If you are getting coolant temp readings like that then you know it is screwed up. But if you want to spend a **** ton at the dealer then so be it.

Ong2764

Ok do you know a DIY for the CTS? I tried searching, but couldnt find anything. My searching skills might be bad

RIWWP

iTrader: (2)

It doesn't look like there is a specific DIY for that replacement yet. Here is a shot someone posted up for where the sensor is. Looks like a bit of irritation to get to, but entirely doable without having to get a dealer involved.

Ong2764

So just an update guys, heard back from the dealership, apparently it was the ECU sending out false readings, so they formatted it and been running good. They did a compression and coolant pressure test and it passed with flying colors. Will hear back more from them tomorrow, seeing if I can get my car back tomorrow.

BigCajun

iTrader: (1)

Good news!
It's quite a relief when things work out, yes?

Ong2764

Yeah the dealership here reprogrammed the ECU, because apparently it was thinking that the old engine is still on thus resulting in power lost, they did a complete wipe and now its running great. It was def a relief that my car is ok. Thanks for all the help though.