2001Montana Transmission

[joeshannallie]

I need some advice on what would cause the van to not have the power to drive up on some car ramps? I put it in drive and it starts to go up on them and then it like it has no power and the motor just revs up. I know it needs some shift solenoids. It drives fine on the road except for the occasional hard shift. I have only owned the van for a few months and do not know the history of it. Please reply soon.

 

[Steelcity]

how many miles on the tranny/van ? ever have any problems driving up hills or accelerating of the line ? maybe the frame or undercarriage is hitting the ramp part and stopping you ? I guess it is possible that the tranny is slipping under hard load but I would think you would feel some sort of slipping/trouble when driving it .

 

[joeshannallie]

It has 153000 miles on it. It is not hitting anything on the ramps. Honestly since I have had it it has been all in town driving and no hills or anything. I think the problem maybe where the fans do not work correctly that it may have about destroyed the trans. I have tried everything there is to try on the fans except a different ECM and they will not work properly. They work fine with a toggle switch but the wire to the switch gets very warm. And yes it is 10 gauge wire and the highest rated switch that I could find. With the key in the on position my multi meter reads 4 when I check the wiring to the coolant sensor. I guess I will have to try and find any bad wiring if possible.
How do I check the sensor to see if it is working properly. It is new but I know you can buy bad "new" parts. Please reply soon.

 

[Steelcity]

Not sure what to tell you about the fans , I do not know the sequence of order. I would guess the fans would only draw a couple of amps and your #10 wire should have plently of capacity. I have no idea of why it would be getting hot? Is there any restriction on the fans ? Maybe something stuck in them ? Maybe the ECM sees the high amp draw and shuts down the circuit, this is all guessing . What is the current draw when the fan(s) are on ? Good luck and keep us posted

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[joeshannallie]

No there is no restriction near the fans. How would I check the draw on the fans? I took the relays apart just to look at them when the van is running and the one is like it is closed when it is running but no fan is running. When I turn the van off the relay is back open. Also when it is running I can manually make one of the relays close and then both fans will kick on and run as long as I am holding the relay closed. This is totally a mystery. If the wiring was bad somewhere you would think the fans would not work at all when I make them manually work by closing the relay. Oh well I am about ready to put a best offer sign on it and move on.

 

[Steelcity]

By you testing the relays, it sounds like the problem is before the relays. Whatever is to trigger the relay(s) is not working correctly . But this info you probably know . You need someone with this type of experience or someone with a wiring diagram . A service manual would be nice. There is one of our members (Roadrunner) that is a tech or maybe a gm tech maybe he could shine some light on this ??? Maybe you already tried this but trace out the wiring from the temp sensors back to the relays/or ecm look for broken/burned wires inside the wire loom(that plastic covering)

 

[joeshannallie]

Thanks for your help. I dug into the wiring a little and the light gray wire leading to the fan connector has been cut and is bolted to the engine block. from everything that I have read it leads me to think the ECM is corrupted and not sending the power or whatever it does for the fans to turn on. I found somewhere that to unhook the cts and the fans should come on. Well they dont. I may get another ecm and have it programmed to my van and just see if that was the problem. I might as well since there is nothing else to do or try.

 

[Steelcity]

did you ever try hooking back up that light gray wire to see what happens ?

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[joeshannallie]

No I have not tried that yet. Do you know much about the ECMs having to be programmed? I found one with the exact service number and hardware number. Also it has the exact four letters on it as mine. DMXM, and if I am understanding right then it will not have to be reprogrammed.

 

[Steelcity]

no dont know much about ECM's , I do know that the bcm has to be programed no matter what , it has to be assigned the car/van VIN # so I would assume the same for the ECM.