Slow94Formula

iTrader: (18)

I am using a sensor from a 98 fbody in my swap to retain the function of the in car gauge.

Question number one: The computer sees about 40° less than what the gauge sees. I believe the gauge in the car is WAY closer than what the PCM sees. Is it possible that the dash will read right, but the computer will see a different value?

Second question is: Is a 1998 sensor identical to 99-02 when it comes to resistance or could that be throwing off the pcm? My understanding is that the 98 is the same in every way except that there is an output for the dash gauge.

I was talking to my tuner and he suggested that the 98 sensor possibly uses a different resistance than the newer ones and had never heard of someone using a 98 sensor in a swap. He also said that there are two separate resistors within the one sensor. Is this true? and is it possible that the one resistor for the PCM signal is bad/has a bad connection?

The computer has a code in it (p0118 Engine Coolant Temperature Circuit High Input) and I have checked both power and ground to make sure that they are right. I have 5.2 volts at the power wire and the ground to the PCM is good as well.

What I am hoping is that putting in a new sensor will fix my issue, but I am wondering if someone can help and confirm my assumption.

Thanks in advance!

1nasty86

iTrader: (63)

The guy in the post above yours has the same code being thrown and he has replaced the sensor and still gets the code

Slow94Formula

iTrader: (18)

I see that... Now I am second guessing my wiring after looking at pigtails on ebay. Anyone have a picture of their coolant temperature sensor connector showing which slots the PCM ground/signal and gauge signal wire are in?

Right now the ground on mine is in the right if I am facing sensor from the drivers side... I'll be pretty embarrassed if that is wrong.

bww3588

iTrader: (49)

I would do this...put the correct sensor in for whatever year your pcm is so it reads correctly. Then put the 98 sensor in the other cylinder head and wire your dash gauge to it.

Slow94Formula

iTrader: (18)

Cut wires and swapped them. Made zero difference in what the PCM sees... The new sensor that was supposed to be here today was for a v6. NO ONE in this area has a 3 wire sensor. Not a soul.

Taubr Unit

iTrader: (32)

im trying to do this swap right now. My PSI harness came with a 2 prong plug but i want to use my lt1 gauges so im switching to the 3 prong. Bought both the sensor and pigtail from AutoZone but now i dont know what wire is what. The 2 prong is black/yellow, black is obviously ground and yellow is signal to pcm, but on the new pigtail i assume black is ground again but what about the blue and gray one? What one is for the computer and what one is for the gauge? What did u end up doing?

Slow94Formula

iTrader: (18)

The one that is bottom center on the connector (appears to be dark blue on yours) is what goes into the car. The other two wires get plugged onto the computer.


Since I never followed up this thread... The issue I was having when I started this thread had to do with some wires that were messed up in my harness. If I remember correctly they were some ac wires that were touching in the harness since I didn't have them plugged in.

Taubr Unit

iTrader: (32)

Cool thanks, so your gauge on your cluster works fine and is accurate?

Slow94Formula

iTrader: (18)

Yep. Seems to be right in line with what the computer sees.

Taubr Unit

iTrader: (32)

ok cool