2003 LB7 4x4 with 125k miles. About a month ago I started it in the morning, made a u-turn on the property, then stopped to get something out of the shop. Never turned the engine off. Jump in, put it in gear and nothing. Checked the fluid level which was fine. Back in gear got it to engage by revving the motor some. Same thing in reverse.
Started driving down the road and seemed to act okay until I slowed for a stop sign. During the 2-1 downshift it banged hard! Take off, it bucks a bit and goes into limp mode (stuck in 3rd gear).
Over the course of the day I start and stop the truck a few times. About 1 out of 5 times the truck would drive and shift normal. The other times it either wouldn't go into gear or it would go into limp mode.
BTW, the gear selector light works good.
Took it to the dealer who said it needed a new (or rebuilt) valve body complete with new solenoids in the valve body. Blamed the issue of having to rev the motor to get it to roll on a check valve messed up in the valve body allowing the torque converter to drain back into the trans.
So with the new valve body the truck seemed to be fixed. Same night I got the truck (last night) I put about 10 miles on it when I got another HARD 2-1 downshift. But then the trans seems to work normal.
Next day (today) with about another 10 miles on the truck, I get in (on a warm start) and it wouldn't engage again. Revved the motor a bit and was able to get it to engage. Have to do this in both drive and reverse. So I nursed the truck home. It kinda shuddered a few times but never went back into limp mode.
Recontacted the dealer who says it probably needs an ECU because it's not reading from the speed sensors.
It does have a P0700 trans code. I don't have the tools to read further for more specific codes. Shift indicator light reads correctly and it does seem to go from 2hi to 4hi to 4Lo with no issues (of course I've got the rev the motor in each range to get it to move but the gearing seems right and the indicator lights are correct). Speedometer also reads correctly and smooth.
So now I have a new valve body in the trans but it seems all the same old symptoms are back. I think the dealer is now just trying to throw parts at the problem. I'm sure other have had the same or similar issues with the same truck and has come across some kind of fix.
PLEASE HELP! Thanks in advance!
Today I was able to get the following codes;
P0380
P0404
P0700
P0727
P0726
Started driving down the road and seemed to act okay until I slowed for a stop sign. During the 2-1 downshift it banged hard! Take off, it bucks a bit and goes into limp mode (stuck in 3rd gear).
Over the course of the day I start and stop the truck a few times. About 1 out of 5 times the truck would drive and shift normal. The other times it either wouldn't go into gear or it would go into limp mode.
BTW, the gear selector light works good.
Took it to the dealer who said it needed a new (or rebuilt) valve body complete with new solenoids in the valve body. Blamed the issue of having to rev the motor to get it to roll on a check valve messed up in the valve body allowing the torque converter to drain back into the trans.
So with the new valve body the truck seemed to be fixed. Same night I got the truck (last night) I put about 10 miles on it when I got another HARD 2-1 downshift. But then the trans seems to work normal.
Next day (today) with about another 10 miles on the truck, I get in (on a warm start) and it wouldn't engage again. Revved the motor a bit and was able to get it to engage. Have to do this in both drive and reverse. So I nursed the truck home. It kinda shuddered a few times but never went back into limp mode.
Recontacted the dealer who says it probably needs an ECU because it's not reading from the speed sensors.
It does have a P0700 trans code. I don't have the tools to read further for more specific codes. Shift indicator light reads correctly and it does seem to go from 2hi to 4hi to 4Lo with no issues (of course I've got the rev the motor in each range to get it to move but the gearing seems right and the indicator lights are correct). Speedometer also reads correctly and smooth.
So now I have a new valve body in the trans but it seems all the same old symptoms are back. I think the dealer is now just trying to throw parts at the problem. I'm sure other have had the same or similar issues with the same truck and has come across some kind of fix.
PLEASE HELP! Thanks in advance!
Today I was able to get the following codes;
P0380
P0404
P0700
P0727
P0726
