P0740 code.

[kennythewelder]

So, I get in my truck this morning. First it up, and all is good. Go to my breakfast spot, kill the truck, go inside, and pick up my breakfast sandwich. Get back in, fore the truck up, and no tach, and CEL is tripped on. I put it in R back up, then OD, as usual, and it has no power, but does move slowly. Like the trans has issues. Also the speedo isn't working. I drive it to work, ( only about 3 or 4 blocks) and it's slow to take off, but will go down the road. Almost like the trans is slipping at first. Pull the codes, and get p0740. Torque converter issue. I call up my trans shop, and he said, it sound electrical. Check the fuzes, and let him know. Being at work, makes it hard, to do anything on my truck, but OK, I will check the fuzes. Suggestions are welcome.

 

[89obsSB]

So, I get in my truck this morning. First it up, and all is good. Go to my breakfast spot, kill the truck, go inside, and pick up my breakfast sandwich. Get back in, fore the truck up, and no tach, and CEL is tripped on. I put it in R back up, then OD, as usual, and it has no power, but does move slowly. Like the trans has issues. Also the speedo isn't working. I drive it to work, ( only about 3 or 4 blocks) and it's slow to take off, but will go down the road. Almost like the trans is slipping at first. Pull the codes, and get p0740. Torque converter issue. I call up my trans shop, and he said, it sound electrical. Check the fuzes, and let him know. Being at work, makes it hard, to do anything on my truck, but OK, I will check the fuzes. Suggestions are welcome.

What year is your truck?

 

[89obsSB]

Sounds like it’s defaulted into 3rd gear

So, I get in my truck this morning. First it up, and all is good. Go to my breakfast spot, kill the truck, go inside, and pick up my breakfast sandwich. Get back in, fore the truck up, and no tach, and CEL is tripped on. I put it in R back up, then OD, as usual, and it has no power, but does move slowly. Like the trans has issues. Also the speedo isn't working. I drive it to work, ( only about 3 or 4 blocks) and it's slow to take off, but will go down the road. Almost like the trans is slipping at first. Pull the codes, and get p0740. Torque converter issue. I call up my trans shop, and he said, it sound electrical. Check the fuzes, and let him know. Being at work, makes it hard, to do anything on my truck, but OK, I will check the fuzes. Suggestions are welcome.

sounds like it’s defaulted into 3rd gear.

 

[east302]

Can’t remember what year you have, but here’s the code table for a 98. It does sound electrical.

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[89obsSB]

So, I get in my truck this morning. First it up, and all is good. Go to my breakfast spot, kill the truck, go inside, and pick up my breakfast sandwich. Get back in, fore the truck up, and no tach, and CEL is tripped on. I put it in R back up, then OD, as usual, and it has no power, but does move slowly. Like the trans has issues. Also the speedo isn't working. I drive it to work, ( only about 3 or 4 blocks) and it's slow to take off, but will go down the road. Almost like the trans is slipping at first. Pull the codes, and get p0740. Torque converter issue. I call up my trans shop, and he said, it sound electrical. Check the fuzes, and let him know. Being at work, makes it hard, to do anything on my truck, but OK, I will check the fuzes. Suggestions are welcome.

I found a tsb that maybe something to checkout. I’ve ran into this before in the past at work and it ended up being an ignition switch.

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[kennythewelder]

What year is your truck?

97, Vortec 350, no passlock.

 

[kennythewelder]

Thanks guys. Looks like I will have to have it towed home, so I can work on it.

 

[kennythewelder]

So 1 more question. The truck still drives under its own power. Will it hurt the transmission if I just move the truck around the yard, just to work on it? The torque converter just isn't locking up, rite, but the transmission is still getting fluid, and working correctly, rite? It's just the torque converter, that's not locking enough to move the truck at normal force, rite? The truck does back up, does move forward, it just acts like the trans is slipping, but that's BC of the torque converter, rite? (Truck is an early 1997, Vortec 350), 4L60E , was rebuilt 2 years ago in February, with HD master rebuild kit, Corvette servos, shift kit, new torque converter, all done by a very reliable shop, local to me. Also have noticed the check gauges light, on the dash, had been flashing some times , first thing in the morning, but goes off, before I reach the end of my drive way, about 75 feet. That light is not on now.

 

[HotWheelsBurban]

Hmmm, sounds like it might be 4L80E time....

 

[Schurkey]

If the trans is slipping, it's in trouble.

If this is a problem like the bulletin shows, in "limp home" mode going forward, it should be in 3rd gear. You'd have really-crappy acceleration, and the converter would be working pretty hard--but short trips should be OK.