Locks up when hot

[Cumminsnewbie]

it seams like the converter locks up when truck is hot. The truck seems to shift ok. Was wondering if the throttle valve could be sticking in the valve body? I replaced all the electronics on the valve body and adjusted the bands as well. I am new to the Cummins world, it’s a 1999 47re. It was locked up when I bought the truck

 

[JKellis]

it seams like the converter locks up when truck is hot. The truck seems to shift ok. Was wondering if the throttle valve could be sticking in the valve body? I replaced all the electronics on the valve body and adjusted the bands as well. I am new to the Cummins world, it’s a 1999 47re. It was locked up when I bought the truck

From one newbie to another, and somebody please correct me if I'm wrong, but here goes. The TCC solenoid receives continuous voltage while the truck is running, with a normally open ground. The PCM locks the TC by grounding the TCC solenoid. A bad ground can cause the TC lock to fail. I would try checking the wire from the transmission to the PCM for worn insulation that could be grounding the TCC solenoid. I don't remember the wire color or the connector pin number, but there are several threads on here that address installing a manual TC lock switch that mention wire color and correct connector pin.

 

[Cumminsnewbie]

Thank you for you reply. I will try to describe the situation in more detail. When I bought the truck the transmission was locked up meaning when you dropped it into gear it would kill the engine, the guy said he had been driving it and parked it in his driveway and went back later to drive it and it stalled every time he put it in gear. I had it towed home and I was laying underneath it and moved the tv cable back and forth by hand, then the truck was able to move.
After driving it a while I pulled in my driveway and it did the same thing. So I decided to pull the pan and found a broken band anchor. I replaced the anchor and band strut with aftermarket and while I had the valve body out I replaced all the electronics. If I make a short drive the truck is normal when I get back, if I make a longer drive when I get back to the driveway and stop, it’s like your power braking it and after you put it in park or neutral and drop it back in gear it stalls.
I let it sit a couple hours without touching it and tried it again and it was still locked up. Then with the key off I mashed the throttle 4 or 5 times then started it up and put it in gear and it was fine. So I’m not sure if something in the valve body is sticking when it’s hot or is it electrical.
The check engine light has never been on during any of this, and yes I checked to make sure it works. Is The wire your referring the ground wire?

 

[Terry]

A good computer scan tool with live data stream will allow you to determine if the lock up is being commanded by the PCM. Any transmission shop should be able to help you with this during a quick road test when the problem is present.

 

[cerberusiam]

TC is failing.

 

[JKellis]

Thank you for you reply. I will try to describe the situation in more detail. When I bought the truck the transmission was locked up meaning when you dropped it into gear it would kill the engine, the guy said he had been driving it and parked it in his driveway and went back later to drive it and it stalled every time he put it in gear. I had it towed home and I was laying underneath it and moved the tv cable back and forth by hand, then the truck was able to move.
After driving it a while I pulled in my driveway and it did the same thing. So I decided to pull the pan and found a broken band anchor. I replaced the anchor and band strut with aftermarket and while I had the valve body out I replaced all the electronics. If I make a short drive the truck is normal when I get back, if I make a longer drive when I get back to the driveway and stop, it’s like your power braking it and after you put it in park or neutral and drop it back in gear it stalls.
I let it sit a couple hours without touching it and tried it again and it was still locked up. Then with the key off I mashed the throttle 4 or 5 times then started it up and put it in gear and it was fine. So I’m not sure if something in the valve body is sticking when it’s hot or is it electrical.
The check engine light has never been on during any of this, and yes I checked to make sure it works. Is The wire your referring the ground wire?

Sorry it took so long to get back. The wire I was referring to is Orange with a black tracer. It is pin 11 on connector C2 at the PCM and Pin 7 on the transmission connector. If this wire goes to ground, the TC is locked. Before you go back into the trans. take a look at your harness, doesn't cost anything to look.

 

[JKellis]

Sorry it took so long to get back. The wire I was referring to is Orange with a black tracer. It is pin 11 on connector C2 at the PCM and Pin 7 on the transmission connector. If this wire goes to ground, the TC is locked. Before you go back into the trans. take a look at your harness, doesn't cost anything to look.

Forgot to mention, grounding that wire will not lock the TC when the shifter is in "manual" first or second position, unless the VB has been mod. to allow it to lock. From what I understand, grounding that wire will lock the TC in all gears with the shift lever in D.

 

[cerberusiam]

If the TC was actually locked the engine would die. Immediately. Inernal sprag will fail and make it act like it is locked when actually it has no stall. The fact it only happens when it is warm is a good indication the problem is the TC.

 

[Cumminsnewbie]

Thanks to all for your suggestions. It was the torque converter.