Engine/Transmission (1998.5 - 2002) No cruse or torque converter lock up -- do they have something in common??

[Misenheimer]

I have a 99 3500 that has a fresh transmission but no lockup on the TQ, (new TC) It also has no cruise, the light is on but not working. I looked at the vacuum lines and they seem OK. Is there something in common or are there two seperate problems??



Thanks

Robert

 

[DavidC]

Here is one scenario with the thermistor. If you do not have lockup overdrive will be locked out. This is only one scenario.

Dave

 

[DavidC]

Wiring diagram PCM and trans. control

Dave

 

[DavidC]

Chart for trouble shooting

Dave

 

[Misenheimer]

Thank you Davd. This will giveme a place to start when the rain stops.

Robert

 

[DavidC]

Forgot the cruise control

Dave

 

[Misenheimer]

I am now where I can get to work on this problem, vacation is over.

The cruse fixed itself must have been a switch problem from sitting.
Now I have my scan tool and get P0743 out of it. It is strange (to me) that when I clear the code there is no over drive but cycle the switch and the code reapperes along with overdrive working. The connector on the transmission seems to be ok. What function does the speed sensor play in this?? I thought that it might be the reason for the cruse not working but it has returned without lock up.
Need to get out the ohm meter and check the solonids
Thanks for your input
Robert

 

[DavidC]

743 code

 

[DavidC]

Speed Sensor. Ohmming across the 2 pins should be around 600 ohms.

Dave

 

[DavidC]

More Speed Sensor info

Dave

 

[DavidC]

Temperature Thermistor

Dave

 

[Misenheimer]

I think that the lockp solonoid is open. It is difficult to get on the pins but the OD solonid will bring down a 9v battery to 190mv the lock up had no change. I think I will put in a shiftkit while I am in there. Who makes the best one?? I have used transgo and it was good. I want a plate to go wih it though.

 

[DavidC]

Can't help you there as mine is all DTT. I do not remember hearing anything bad about Transgo.

Dave

 

[cerberusiam]

Either the solenoid is bad or the harness, at times it is hard to tell. Might as well replace the hwole thing while your at it, along with a GM gov solenoid if your doing a shift kit.

The Transgo is a decnet kit and works well. PIA to put in though compared to others and ther eis no going back as there is drilling and blcoking ports involved. You don't want to make a mistake with it.

Superior makes a shift that is also really good and is a lot less intrusive than the Transgo, read that simpler. You might have to source some parts from Sonnax along with the kit for upgrades.

 

[Misenheimer]

I just ordered a Fairbanks kit with a new steel seperator plate. I have used this one in the past and did like it. I had a failed overrun clutch and defeatng the accumulator fixed it for the last 65k miles.
Now another problem has come up --- the connector is flat with three pins and the correct connector is round with four pins???? I know that it has been into but could they have put in an earlier solonid set up???
Please tell me more about the GM solonid adnd what it takes to get it in. I have not ordered them yet but soon. Looks like $215 for everything including the connector repair kit $45.
Are all four wires used in the 98. 5?? I need to open the harness to look.
Thanks for your help
Robert

 

[cerberusiam]

What connector is flat with 3 pins? That is a 47RH connector. The 47RE which your truck should have is round with 7 or 8 wires. You need to make sure you get the correct harness for an RE transmissions.

The GM solenoid is easy to install, 4 bolts and 2 wiring connections. You will have all of that apart when you put the shift kit in.

On your truck, not all the wires are used like the 99 and up trucks so you have to get the right harness. The temp sensor was moved to the pan for the later trucks but the connector is still round.

 

[Misenheimer]

Back under the truck. I was on the connctor for the neutral start switch. my bad

 

[Misenheimer]

I have the shift kit in with all new solonoids ( 4 ) and it is working with lockup. Now it stacks shift 1-2 as soon as it is moving 2-3 soon after. Will the higher line pressure cause this?? I adjusted the TV cable to where there is no slack in it at full open. Will the 100 ohme resistor delay the shift points?? Why do they want to put the resistor in the orange wire?? It is the 5V supply?? I Put one in another 2500 that I did and it works ok but just wondering. Could I sub a 40 turn precision pot for the 100 ohme and be adjustable? I did remove the check ball also and went performance - competition with the kit.





Thanks

Robert

 

[Misenheimer]

any ideas???