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Can automatic trans solenoids alone cause a transmission to not go into gear?


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Here's my question - can the automatic transmission solenoids alone cause it to not go into any gear?  

 

This transmission had a smashed pan and solenoids which I repaired like 40,000 or something miles ago and it ran fine until recently.   I replaced some of the solenoids and wiring, not all of it - so I'm wondering if there could have been another damaged solenoid/wiring I didn't notice that finally failed? 

 

2002 VDC automatic. It won't go into any gear at all - it just sits there and idles perfectly with no change as I move the gear selector. 

Disconnecting the TCU changes nothing and I'm nearly positive it's not the linkage. 

 

Normally I'd just assume it's a torque converter failure - but with the prior solenoid damage and being uncertain how precisely they work I wanted to check. 

 

 

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Not likely. Normally if solenoids fail the transmission will stay in 3rd gear forward, and you would still have reverse.

 

Sounds like either dead trans pump, blown out seal somewhere internally, or possibly torque converter failed. Maybe the pickup filter fell off and it can't pull any fluid.

There are some ports on the side of the case where you can check line pressure. Or pull one of the cooler hoses off and stick it in a bottle and see how much/how fast fluid gets pumped into it. That would tell you if it's a pump problem.

 

When you move the shifter out of park can you push the car? Would rule out a broken shift cable.

Does it roll if it's in park? Broken axle...

Edited by Fairtax4me
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Great thanks - with that prior pan/solenoid smashing issue I wanted to make sure it couldn't be the solenoids. 

 

Fluid movement check - good call, i'll pull a hose. 

 

or possibly torque converter failed...

 

Prior to failure, for a couple months, the torque converter would chatter (i think that's what it was) when warming up, and it was throwing some solenoid codes.  So I was already expecting issues, just wasn't sure if it was related to that pan smashing incident. 

 

 


When you move the shifter out of park can you push the car? Would rule out a broken shift cable.
Does it roll if it's in park? Broken axle...

 

Oh right, yeah park works fine and I can push the car so it's all working. 

 

 

, or possibly torque converter failed. 

 


When you move the shifter out of park can you push the car? Would rule out a broken shift cable.
Does it roll if it's in park? Broken axle...

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Just to avoid a possible expensive fix, make sure the shift cable isn't binding or is adjusted properly and well lubricated. Does your car have the PRND indicator on the dash? If so, make sure it matches up with the position on the shifter.

 

Yeah the indicator is moving and the car comes out of and goes into actual Park just fine, so the mechanisms are all working. 

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*** Odd change of events - I revved the engine up to like 6,000+ RPM's and held it there for a few seconds (because what do I have to loose?) and the car slowly started going in reverse and after 10 feet backwards, 10 feet forwards....it seemed to be improving.  It's a slow engagement, like a slipping clutch, but seemed to be improving. I didn't "drive it" just went forward/backward a few times for a few feet. 


What does that mean? 

I'm thinking it means it needs a tall, cold bottle of Trans X...!  LOL

 

 


Yes - it's full.  It acts like it's in neutral in all gears (except in park, it's in park).  No noise, no nothing, just neutral, engine purring right along without a glitch. 

Stupid question, but did you check fluid level? What does it do if you put it in gear and give it gas?

Well - until that little 6,000+ rpm stint I just pulled... 

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I know that you know that you should know before taking a guess. Lol. There may be additional codes now.

I've had a TCC solenoid throw codes up until I changed the solenoid but it didn't fix the shifting issue it was having. It still revs out and slams in to 2nd. But this was on a different car with a different transmission. And it didn't render the car inoperable. In this particular case, the solenoid was gunked up from the TC basically deteriorating.

Doesn't mean that's what is happening in your case. To be honest, I would suspect that a bad solenoid would impede shifting, not necessarily movement. Perhaps it's time to rebuild or swap it out?

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TCC solenoid only affects the lock-up clutch in the converter. That's only engaged once the vehicle is moving above a certain speed.

 

Line pressure solenoid it fails it should fail so the trans gets full pressure. Maybe if it physically broke/fell off of the valve body it could dump enough pressure to cause a total non-engagement.

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You my friend need some throne time with engineering schematics, TCM logic algorithms and a blue pill.

As for me, I'll stick to car and driver and throw a solenoid at it when I'm done. Lmao

Hahahaha. Totally get that, much more efficient your way. Your description is keen, Ive done lots of that and built software for spacecraft, not on the throne though Lol.

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