dang coolant sensor (question)

adam92sl · 10-07-2002, 06:34 PM

OK, on Saturday I pulled apart my cooling system and found my water pump to have gone bad. I replaced two hoses, new coolant and replaced the water pump. Here is where it got crazy. I attempted to replace my coolant temp sensor (the two wire kind). I picked it up from NAPA, it is brass. I have never replaced it so immediately I can tell the difference. My old one was twice as heavy and shorter. So being anal, I have to torque the thing. Well the new brass fitting screw portion busted in the engine (prior to reaching torque limit). Luckily my landlord had an "easy out" and it removed it from the engine. I reinstalled the old sensor.

My questions are:
1) My SES light stays on even after I resetted the PCM (disconnect battery). Why?
2) I thought Saturn went back to the old brass CTS. Was my mistake buying from NAPA and not Saturn?

Thank you,

adam92sl · 10-08-2002, 06:29 PM

Can someone explain the differences between the temperature sensor and the coolant temperature sensor? I think I may have fumbled to much with the temp sensor. I have a SOHC 92. It flashes a code 15 which might mean I did something to the temp sensor. But the car also runs hard at start up. Any suggestions?

rduncan · 10-08-2002, 10:46 PM

I don't know f I can answer all your questions but my 94 SL2 has two sensors, one for the gauge (single wire) and one to the comouter (two wire).

I purchased the 2 wire sensor at my Dealer for under $10 bucks so at that price I felt the dealer was the best place to buy. As far as your code I checked the Chilton manual and a code 15 is shown as "ECT Circuit - Temperature Out of Range Low". if that gets you started diagnosing the problem.

Rick
Albuquerque, NM

Estairiker · 10-08-2002, 10:57 PM

I believe that the coolant temp. is the temp of the coolant and that the temp. is for the whole engine.

adam92sl · 10-09-2002, 12:45 AM

Yeah, its just strange to figure out. I would hate to buy another sensor. Anyways the chronus website says http://www.cronusmotorsports.com/tech_articles/dtc.html):

DTC 15 will set if:

The ECT reads below -35ÂºC (-31ÂºF).
The engine has been running longer than five minutes with a temperature
less than -35ÂºC (-31ÂºF).

Like my car operates under -35c. I just wonder which one I screwed up....

Estairiker · 10-09-2002, 01:28 AM

Wish I could tell you, but I have no idea. Sorry!

CelticShadow · 10-09-2002, 01:36 AM

Quote:

Originally Posted by adam92sl

My questions are:
1) My SES light stays on even after I resetted the PCM (disconnect battery). Why?
2) I thought Saturn went back to the old brass CTS. Was my mistake buying from NAPA and not Saturn?

1) Are you saying that the light is on even when the battery is disconnected?

2) I would say quite possibly the one from Napa is just bad. But just to be on the safe side, get the one from Saturn and replace it with that. Remember to disconnect your battery again, and leave it disconnected for a while so everything resets.

wolfman · 10-09-2002, 02:54 AM

Also check the connector for the sensor (the plug) If it is corroded it may just not making contact with the new sensor. Hence the sensor is fine but is not sending a good signal to the PCM. The 2 wire sensor sends data to the PCM indicating the engine coolant temp. The 1 wire sensor just sends temp data (coolant AGAIN) to the guage. If the gauge is working OK, no need to change that one.

adam92sl · 10-09-2002, 03:56 PM

After a little more inquiry (reading my NAPA receipt). I asked for the coolant temp sensor and recieved the temperature sender. The box was pretty vague and I never read receipts. But this one had the abbreviations. I guess they were confused. All I did was check that it was brass.

I will check my wiring: that may be the problem from the amateur car mechanic.

Oh the SES light comes on after the car ran for 5 mins. or so.

Thanks.