4L60E Trans P0758

[redridder1960]

my 1998 silverado with a 5.7 2wd. After 3 months off not being used, I jumped into my truck, as soon as it went into tcc, it went back into 3rd and the check engine light came on. P0758 code. I changed both of the solenoids(1-2and 3-4) vltage at both 12.0 volts. I can manually ground each solenoid and hear it click. I ohmed out the tan and green wires. at 1.8U to ground. When I first start up truck and put it into gear (od) it will shift all the way to tcc, then it goes back to 3rd. I have to manually shift to 1st at stops but once rolling will not go all the way to tcc. I unpluged the red connector at the ecm under the hood. The bottom row of pins, 11 and 12 going from back to front are the a and b solenoid ground wires. They ohm out at 1.8. I can manually activate each solenoid by removing trans pan and grounding the green wire on a and the tan wire on b. I know they are getting enough voltage. The ground circut is not working right. If anybody can help me, please. All the trans shop say I need a rebuild at $1700.00 plus. I believe it is a ground issues. I went to my locale chevy dealer and the parts man told me the soleniods where a big issue, that is why I changed them, I am $200.00 in the hole and need some straight answers. All the trouble trees tell to look for frayed or chaffed wires at the bell housing. I can find none. The next thing is to change the ecm. I dont want or can afford to keep changing parts. I know some one has bared my pain. please em me at [email protected] and you will be in my eturanal gratatude. I dont know why but some have changed the ignition switch...to solve this problem...????

[chpspecial]

Try checking. Checking the round trans plug for loose or cut wires. That is what happened to me... Might even be a rodent issue since you say the truck was parked...

 

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