Good post DW! God bless, Sensei
1981 code 15
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Joined: Mar 2007
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From: League City TX
St. Jude Donor '08-'09-'11
1981 code 15
torque converter is not locking in. I get temperature to the water temp. guage in the dash, but trans. is not getting info it needs to lock up the converter. Any ideas?
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Joined: Jul 2004
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From: Scottsdale Arizona
The sensor that the CCC uses for the lock up circuit is not the same as the one used for temp gauge. I don't think it's the one on the right side of the head either, which is for auxiliary fan.
I spent a few minutes this morning with the service manual trying to figure out which is the sensor used for this circuit. Hopefully someone will chime in. Otherwise, I'll keep reading.
I spent a few minutes this morning with the service manual trying to figure out which is the sensor used for this circuit. Hopefully someone will chime in. Otherwise, I'll keep reading.
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Joined: May 2006
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From: Dayton, Ohio
I would be looking at the vacumm sensor(map sensor) mounted on the firewall next to the air relay which is between the wiper motor and the drivers side hood latch.It should have a vacumm line and 3 wires gray,green and black.
EDIT-Oops Sorry I was thinking about a 1980 with no computer.
Here is a testing procedure that you should go through step by step.Its going to be pretty hard to help you via a computer.There are lots of points you have to check.Hope this helps and sorry for the wrong info.
EDIT-Oops Sorry I was thinking about a 1980 with no computer.
Here is a testing procedure that you should go through step by step.Its going to be pretty hard to help you via a computer.There are lots of points you have to check.Hope this helps and sorry for the wrong info.
Last edited by ...Roger...; Jun 10, 2007 at 04:09 PM.
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Joined: Mar 2007
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From: League City TX
St. Jude Donor '08-'09-'11
Thanks for the replies. We'll keep looking. Not sure if I can do the flow chart test. What test light do I need? If it is the ECM - where do I get one? The car idles high (1500 rmp or so) for a while when started.
Might try the sensor next to the thermostat. Just got the car yesterday so we've got some things to work on. Quite a difference from the other 2 vettes!
Might try the sensor next to the thermostat. Just got the car yesterday so we've got some things to work on. Quite a difference from the other 2 vettes!
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Le Mans Master
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The TC lock up is controlled by the vehicle speed sensor in the speedo, and over rided by the brake switch.
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From: tx
I'm guessing that there are two or three water temp. sensors on this motor. One sends signal to the water temp. guage in the dash and is probably located in block or head on the drivers side. Another on the block or head on the passenger side that sends temp. to the aux. fan. And one that sends temp. to the ECM, probably mounted in the intake manifold. Thats the one that probably controls torque converter lock up. The car needs to meet at least three conditions to lock up the torque converter. One is proper speed and there is a sensor around the speedometer for that. Second is engine warm up. The torque converter doesn't lock up when the engine is cold. And I think rpms is the third. Just my guess. 
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From: Scottsdale Arizona
At least four that I know of. The one in the drive's side head is for the temp gauge. The one in the passenger side head is for the auxiliary fan. There are two thermostatic vacuum switches in the thermostat cover. I don't know if any of these three is responsible for the signal to the CCC.
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At least four that I know of. The one in the drive's side head is for the temp gauge. The one in the passenger side head is for the auxiliary fan. There are two thermostatic vacuum switches in the thermostat cover. I don't know if any of these three is responsible for the signal to the CCC.
The stat housing vac sw operate the heat riser, and the EGR enable.
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From: tx
I fixed the problem with the torque converter not locking up on lois lanes 81. It was the temperature sensor located in the thermostat housing behind the air pump. I took the coupler off and tested for voltage across the ground and the lead while the key was on and i got 5 volts reading to the ECM(anything over 4 is good). Then I removed the sensor and checked resistance across the pin in the middle and the inner sleeve and got 700 ohms(anything less than 1000 ohms is good). So it just wasn't making good contact. I looked at the pin in the sensor and at the sleeve in the coupler and noticed that the pin was a lot smaller diameter than the sleeve of the coupler. So I bent the pin over just a little bit and walla. The car now has a locking torque converter in 2nd and 3rd gear.