Need LS1Tech member help...

My 2000 SS temperature sensor/gauge is going crazy jumping from 0 all the way to the red causing the engine to cut off..

I had this problem a while back, i switched out the sensor and pigtail but continued doing the same thing, i ended up cleaning all my ground wires and it stopped for about 6 months. Well its back I already cleaned the grounds again and even added more ground wires. Its still doing it..


Any ideas???

 

Is it possible your sensor is just faulty again?

 

i suggest a new sensor and new connector. mine went bad and that fixed it.

 

When i changed everything the first time it continued doing the same thing..

 

Sounds like a ground problem. Have you checked them all closely? Remember to check other grounds on the car too. Not just the one from the sensor

 

Agree - and include both ends of the negative battery cable which serves as a reference point for the rest of the harness.

 

What am i exactly looking for?

 

Over time, the metal grounding points of contact oxidize/corrode and no longer make good contact. This deterioration, with the possible exception of the negative battery post, is not particularly visible. The usual process is to simply remove the ground, sand it or use something like a point file on it to knock of the oxidized layer (make it shiny) and reinstall it. If the ground bolts to a painted surface a star washer can help. On these cars, the grounds that seem to deteriorate with some regularity are those (2-3) located on the back of the cylinder heads.

 

Cleaned all grounds which were really bad but the car continues the same.

 

Don't forget the PCM-to-engine ground wire. Its 16cm from the PCM in the wire bundle. Let the engine idle while you grab that bundle and move it back and forth....see if that effects anything. When mine was loose it fried my PCM but before that happened it would make the engine run like total hell, barely stayed running.

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Did you check all wires going to the sensor and the sensor itself to see if it is working right?

 

16cm????

 

Currently having a similar issue with a friends Vette. Check your battery, switch it out for a known good one and see if the problem goes away. That seems to be the primary fix on the Vette when this happens. A lot of guys have replaced hundreds of dollars in parts only to find out the battery is the issue. If you have another car, its a no cost test.

 

Yea, when this PCM/wiring guru came to my house from this local Pontiac dealership to help me find out why my engine wouldn't stay running.....he hooked up his scanner and watched it continually say something like....PCM recognized....PCM not recognized....PCM recognized....PCM not recognized........and it kept doing that. He walked over to the PCM and grabbed everything and started moving things around while I looked at the scanner. He said, "you have yourself a loose ground wire." I was like..."ok....".

He had a GM schematic on his laptop of the complete wiring harness for my 1998 T/A. It told him, ", and I'm saying this from memory from over a year ago" that the ground wire is spliced together with 3 other wires 16cm from the PCM.

He went over to the bundle and with a razor knife cut open the plastic covering on the wire bundle APPROXIMATELY 16cm from where the bundle came out of the PCM...and THERE IT WAS. He cut the ground wire AFTER where those 4 wires merged and were soldered together from the factory, sealed off that open end with shrink wrap, then spliced in a new wire to the 4-wire end and ran that end to one of my LS6 valley cover bolts to ground it to the engine. Then used electrical tape to close up the bundle. He said, "screw trying to get behind the engine where the original one was bolted in and came loose". I said fine with me.

Job was done. I know....I couldn't believe it either....so friggin easy if you just have the tools to diagnose and then fix **** so easy.....

There's the wire pictured below that he bolted to the valley cover bolt with the yellow colored plastic crimp end. I gave him $100.00 for coming to my house and spending about 40 minutes there. Little does he know I would have given him $200 because I never would have found that.

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I changed out the battery from my truck to my car and still doing the same thing..


I will try the ground wire in that bundle tomorrow.. I really think thats what it is!!!!!

 

Finally got the computer grounds repaired and re routed so far so good, had car idleling for about 20 minutes and guage did not jump at all. I will test drive it later today...

 

Well guage is okay, BUT no the cars is bogging to down bad... Any thoughts??

 

Final update!!!

The grounds going to the computer was the actual problem it took care the guage issue, as far as the bogging that came after the mod was the fact that i left the MAF ground wire that comes from behind the motor out of the splice.. Added a new ground to that wire and problem solved, car is running better than ever..

Thanks to everyones help.....

 

Awesome man. Glad you found the problem

 

This problem is becoming more and more common as these cars get older and older....................

Thats what I figured it was.

Glad you figured it out. Electrical issues are a bitch to find.

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