Having an issue w/ the CTS readings on the new motor setup. At cold start, w/ ambient temperature outside around 75*, the CTS is telling the ECM the temperature is 105-110* and at idle after warmup the CTS is telling the ECM that the car is running at 240*+...

Readings coming using an AutoXray scanner, so what I am getting through that is what the ECM is seeing...

It is a brand new CTS, put in last weekend when the motor went in...

any help is appreciated guys...

 

New parts don't always mean working parts.

I'd buy another one to verify whether or not the problem is the CTS.

 

The sensor may not be the subject at fault. The wiring could also be bad (this includes the ground at the right rear head.

If you wish to check the sensor, get an another temp gauge and plug it in, then measure ohms and cross reference with this chart (courtesy of Vader)

 

Thanks guys...

Guess I got my work cut out for me...

Yeah I need to recheck those grounds... on both heads to make sure I got them all. Should be three on both head if I remember correctly right?? What about an ECM ground?? Is that one of those on the heads, or is there another ground somewhere else for it?

 

Before you go checking the actual grounds, pull the connector and check the resistance of it to a good engine ground. Should be 0 ohms, or, at most, whatever the resistance of your test cables are. If you come up with anything MORE than 0, then check the engine grounds and the ECM ground.

No need to check what isn't he case.

Then the yellow wire, which is the feed wire. With the plug unhooked, turn the key to the on position without actually starting the car. Measure the voltage across the yellow and black wires. It should read like 5 Vdc I believe.

Do those first. That eliminates some possibilities. Check the ground before the voltage across the yellow wire.