Code 15 and 21 are coming up. I have replaced the CTS, ECM, and TPS(about two years ago but the 21 has been on for that long anyways). but the codes are still coming up. The car stutters when i give it a lot of gas. What else can i check? Thanks.

 

I did a little research. From what I find both circuits use a black wire #452 going to the ECM pin D2. You possibly have a bad ground to the ECM, bad connection or bad/broken #452 wire. Hope that helps.

 

I also seen that they share a ground. So i checked continuity and it seems to be fine. Still confused...

 

It's worth removing, cleaning, and tightening the grounds on the back of the passenger side head. That's where everything gets a reference from.

 

thanks for the reminder. This is what I found. Probably a good place to start. haha

 

well i bolted the grounds back on and reset the codes. Started the car and ran it for 5 mins. code 15 came back right when i started it but 21 never came back. any other ideas? thanks

 

Have you measured the CTS? It should be between 180 and 450 ohms at running temp (disconnected of course). The terminals from the ECM should be ground on one side and +5 on the other (also disconnected).

 

not sure about the ohms but the sensor is brand new. I checked the connector and it is at 5V. with ground.

 

It could just be a bad one. What are you reading the voltage with? Most meters can measure resistance. If yours can't, borrow one.

 

how exactly do you check resistance?

 

This is a good tutorial (scroll down a bit): http://www.ladyada.net/library/metertut/resistance.html

 

With the ECM unplugged, should the D2 pin be grounded or does it recieve it's ground through the ECM?

 

I beleive it is grounded thru the ecm.

 

yes it is thanks. Still not sure why the codes are coming up though.