Engine/Transmission (1994 - 1998) '97 automatic takes off in 3rd gear.

[Pulice]

I purchased a '97 dodge 3500 automatic 2 months ago. The owner told me he thought the PCM was bad. The truck has reverse and takes off in 3rd gear, no first gear, overdrive, or lockup. The truck will take off in 2nd if you manually shift it. I took it to the transmission shop they said it was just the solenoids, they replaced them and still won't shift. So they said it was the computer. After two weeks of us trying to find one (our local dealer can't get it 16 on backorder and no ETA) I orderred one over the internet from a place in Florida who claims they refurbish and program them. Transmission shop installed new PCM last week, still same problem. He tales me the PCM is not giving the transmission a governor pressure command it shoes (0) psi on the command and (50) psi actuall, and that this computer is not working correctly or no good. I am going to talk with him about the over voltage issue on the orange wire and try that. If any one has any other thoughts I would appreciate it.



Thanks

 

[Dieseldemon]

Sounds like its in limp mode check the orange w/black stripe wire from the PCM

 

[PToombs]

I'm in the middle of this myself. Check the thread "Trans Issues". I think I got mine working, too bad the PO fried 2nd right out of it in Limp mode. There is a lot going on in there with the solenoids and such. I have a spare trans, and I had the whole harness in my hand with the Multimeter and the manual trying to figure out what does what.

The short version is, power comes down the orange wire. (the one that gives over voltage) The temp and governor pressure sender are one unit. There is power from the orange wire, ground on the black, and if you test at the trans you will have 5 volts power on the 2 sensor wires too. I thought of the sensors as like an engine sender, grounds thru the block. Wrong! They need the power, and ground back thru the black wire to work correctly. It took me 4 to 5 hours of looking and playing with the tester and wires to figure out how this works. I think I almost have a clue now.

If you need help, let me know. I'm no expert, but Bud helped me a lot, and I'll be more than happy to help all I can to "Pay it Forward".

 

[Pulice]

Yesterday I did check voltage on the orange wire 5. 11V I used a resistor box started with 40 OHM's dropped it to 4. 5V. I drove it nothing differant kept adding more all the way up to 700 OHM's nothing changed. I understand their is a chance that the new solenoids are burnt again, but not sure. The guy at the transmission shop still dead set on it being the PCM. I did read all of "Trans Issues" yesterday before I even posted thanks. As far as checking the orange/black wire, what do you want me to check?



Thanks,

Chris

 

[PToombs]

The orange with black stripe feeds the torque converter clutch control solenoid. It's one of the pair directly on the VB. FYI.

 

[JLandry]

Yesterday I did check voltage on the orange wire 5. 11V I used a resistor box started with 40 OHM's dropped it to 4. 5V. I drove it nothing differant kept adding more all the way up to 700 OHM's nothing changed. I understand their is a chance that the new solenoids are burnt again, but not sure. The guy at the transmission shop still dead set on it being the PCM. I did read all of "Trans Issues" yesterday before I even posted thanks. As far as checking the orange/black wire, what do you want me to check?

Chris,

I'm skeptical that it's the PCM. What are the odds that you had a bad PCM and then got another identically bad one from the supplier in Florida? It's possible of course... but how likely is it (in light of all the other things that could be wrong)? Not only that, but the PCM only helps control shift points, enables 3rd to 4th gear shifting, and controls torque convertor lock-up. If the transmission doesn't even start turning in 1st gear with the gear selector placed in 1, then I don't see how this could logically be blamed on the PCM, or even the governor pressure solenoid (which you already said was replaced), or the governor pressure sensor (which you haven't mentioned). These components control up and down shifts, but not manual gear selection.

Now if I understand your original post correctly, when you place the gear selector in D, the transmission starts turning in 3rd gear and stays there. If you put the gear selector in R, reverse functions normally. If you place the gear selector in 1st, the transmission doesn't turn. If you place the gear selector in 2nd, the transmission turns, but starts in 2nd gear from a stop and not in 1st like it should. If this is correct, then by referencing the clutch and band operation chart in the Dodge service manual, all of the clutches and bands seem to be operating at some point, so that tends to eliminate them... i. e. : there's no problem with the clutches or bands.

That leaves the possibility of some sort of valve body malfunction... like maybe a stuck valve. Has the transmission shop discussed this possibility with you?

Do you know anything about the history of this truck? Could the previous owner have monkeyed around with the transmission valve body... as in trying to put in a shift kit?

Please keep us posted,

John L.

 

[PToombs]

My truck would take off in 1st if you put it there. IIRC, when you put it in 2nd, it will leave in 2nd, not 1st. It's been awhile since I had an auto to drive, so I could be rusty on that. I have't really driven mine yet.

I know the 95 chebby 3500 I drove at work was like that for sure, it saved my bacon in a blizzard once!

 

[Pulice]

John,



I agree with you completly on the PCM issue thats the reason I started this post. I feel we are just throwing parts at it. Everything you said about the manual gear selection is true except when you place it in 1st it takes off in 2nd. Just to recap manually the only gears I have are revers, 2nd, and 3rd do not have 1st,4th, or lock-up.



As far as the history goes, the owner claims when he bought the truck used (3-5 years ago) the transmission was doing the very same thing. He had the PCM replaced and worked fine for several years. He claims he was hot shotting with this truck and the transmission went out, so he took the transmission to be rebuilt. Not by the same shop were I have it, he had it rebuilt in El Paso, TX 3 hours from me. He said when he picked the truck up it did not shift right doing the same as when I purchased it. He took it back they checked it out and claimed the transmission was good and the problem was with the truck some were, so he drove it home didn't want to spend anymore money on it and put it up for sale. How true all of that is I don't know. The outside of the transmission is clean and painted and the shop were I have it at said when they changed solenoids that they didn't see anything wrong or out of the ordinary.



My question to you or anyone else who can anwser this is, the shop explained to me that the way this transmission works is that in it's normal state no wires no computer it is going to take off in 3rd gear, and that the computer has to tell it to downshift. Thats why he thinks it's the PCM or maybe wiring issues. Does this sound correct?



Thanks to all of you who have replied to my problem. I going to try and get the truck from the shop for the weekend and try to check some of the ideas all of you have given me.



Hope all have good Labor Day weekend I will check back on Tuesday.



Thanks again,

Chris

 

[Scrappy]

your pcm is toast most likely. I had the same issue with my durango. in drive it would start out in 3rd. it would not shift into 4th ever and would only go to 1st-2nd. if I forced it with the shifter. the dealer replaced the governor solenoid which WAS bad but didn't fix it, then the PCM which DID fix it. I believe thet the gov. solinoid took out the PCM.

 

[JLandry]

your pcm is toast most likely. I had the same issue with my durango. in drive it would start out in 3rd. it would not shift into 4th ever and would only go to 1st-2nd. if I forced it with the shifter. the dealer replaced the governor solenoid which WAS bad but didn't fix it, then the PCM which DID fix it. I believe thet the gov. solinoid took out the PCM.

Scrappy,



The reason I'm wondering if it might not be a bad PCM in Chris' case, is because his transmission won't even go into 1st gear when he manually places the gear selector in 1st. He said he has no 1st gear. You said above that you could at least manually put your transmission into 1st or 2nd when your PCM was bad.



If I understand the transmission control system correctly, it should manually operate in 1st or 2nd gear when the gear selector is placed in either of those gears, but it wouldn't automatically shift when the PCM is bad or disconnected. But I could be wrong about this as I haven't actually tried it.



John L.

 

[JLandry]

Everything you said about the manual gear selection is true except when you place it in 1st it takes off in 2nd. Just to recap manually the only gears I have are revers, 2nd, and 3rd do not have 1st,4th, or lock-up.

Chris,

Just to clarify...

The transmission doesn't turn when the gear selector is manually placed in 1st gear (not 2nd). Correct?

It turns only in 2nd gear when you place the gear selector is manually placed in 2nd gear (doesn't start out in 1st gear like it should). Correct?

My question to you or anyone else who can anwser this is, the shop explained to me that the way this transmission works is that in it's normal state no wires no computer it is going to take off in 3rd gear, and that the computer has to tell it to downshift.

This is a correct statement only if the gear selector is in the "D" position. In that case the PCM, governor pressure sensor, governor pressure solenoid all work together to downshift the transmission from a default of 3rd gear.

But I believe if the gear selector is placed in 1st gear, then the transmission should start turning in 1st gear, even if the PCM is disconnected. Otherwise, what would be the point in even having the gear selector connected mechanically to the transmission?

Just curious...

Was the governor pressure SENSOR replaced when the governor pressure solenoid was replaced?

Was the transmission control relay either swapped or replaced? It's located in the PDC (Power Distribution Center) on the driver's side fender under the hood.

John L.

 

[Pulice]

To all,



To answer John first, I do not know what solenoids or sensors were changed. I was just told that they originally "changed the solenoids in the transmission". I will find out what exactly was replaced in the next day or two.



I have tried swapping the relays, and no change. I swapped the one labeled transmission control and the ADS relay. Which I'm not sure what this one does exactly but It was clicking when I had the scanner hooked to it doing function tests on the transmission.



To clarify when I place the gear selector in 1st gear the truck will drive, but it is in 2nd gear, when I place it in 2nd, it takes off in 2nd, and 3rd takes off in 3rd.



This weekend I picked the truck up on Friday to do some investigating of my own to verify the information I am getting from the shop and reporting to all of you, and I have found some discrepancies.



First big one is they told me that it is not throwing any codes, not true. The 1st code is P0713 Trans Temp Sensor V. High. This code I tried the resistors again on the orange wire many differant values and could never get this one to clear. The 2nd code is P0748 GOV Pressure Solenoid Circuit-open or short. Which this one seems like a big one like the solenoid is burnt up or the wire is bad. I was using an older Snap ON scanner. I tried clearing these codes but as soon as you drove it both codes would come back even after I put the resistor in (37 OHM, which gave me about 4. 68 V).

The next item with the scanner is that the info he gave me about the desired and actual GOV command pressure is not true. The pressures pretty much matched.



With the scanner I watched GOV pressure and gear selection, and found that when you put it in gear any gear selection the scanner showed 1st gear (brake on not moving), but as soon as you let off the brake and the wheels begin to turn it shifts from 1st to 2nd and then to 3rd if you have it in "D". If you have it in 1st or 2nd it starts in 1st and instantly shifts to 2nd. It does feel like it is doing this. The scanner does also show when it is in "D" that it will shifts in to 4th which is not true and toggles between 3rd and 4th if you use the overdrive button. Just to clarify all these tests with scanner was done parked with the back jacked up, and it does not shift into 4th even thou the scanner shows that it does.



Questions:

1. What wire feeds the GOV Pressure Solenoid from the PCM to Trans? That way I can check this wire for continuity to verify if it's the solenoid or wiring issue.

2. When I installed the resistor on the PCM side it was 5. 11 vdc on the trans side it was 4. 68 vdc, but when you disconnected the 8 pin plug from the trans it was 5. 13 vdc on both sides. Does this sound correct?

3. P0713 Trans Temp Sensor V. High, this one I do not understand. Even after I installed the resistor this code would never stay cleared. The scanner showed about 40' C. Which should be about 104' F.



My plan is to find out exactly what solenoids and if any sensors were changed and report back. The company is sending another PCM, which I am pretty sure isn't the problem, but I will change it out to satisfy the transmission shop, put the scanner on it again and test drive and all that good stuff when ever the PCM gets here. Right now it looks to me like it's a problem with this GOV solenoid and Temp Sensor.



Thanks to everyone who has responded.

I am sorry that the information is changing, but that's why I took the truck for myself to do some trouble shooting of my own and verify some info. which I think paid off. After I get the PCM and check it out which I suspect it will be no change I will take it back to the trans shop.



Thanks again,



Chris

 

[budnate]

set the voltage to your 4. 68 to the trans and replace all the solanoids again, but only after you have control of the V, they are all blown from over voltage, even if you clear the comp they will throw back as sick instantly, also make sure your bands both bands! are adjusted correctly, and one will be right there when you do the solanoids, chances are if it was not beat on in limp mode it will work fine after a little love.



peace, B.

 

[PToombs]

Chris,

#1, the red wire from the trans control relay to pin 1 on the trans plug, and the violet/white from plug C2, (center plug on PCM) terminal B8 at the PCM to pin 5 on the trans plug.

#2, I think that is correct because there is no draw on the wire, which will cause it to drop. Check the voltage with the truck running. Mine dropped from 4. 71 to 4. 28 after I started it.

#3, I had this code come back today myself, but the light went out and the truck drove normal after that. I cleared it when I got home.



I had the gov press short or open code, and it wouldn't go away. I cleared it with the scanner, which is an older Snap On unit, and it came back. Somehow I found a "disconnect battery" in the scanner, which cleared this code. (borrowed scanner so I'm learning) The gov pressure that I'm reading in the scanner is way low. Need to tap in a guage to verify pressure.

I bet the temp/ pressure sensor is blown too.

 

[Pulice]

Pete,

Thanks for the technical information on the wire colors and locations, that will help out alot.



To all,

I did talk to the transmission shop Tuesday and all they changed was the GOV pressure solenoid and GOV pressure sensor. Did not change temp sensor, overdrive, or lock up solenoids. With that said I will put Pete's info to good use and check the wiring on the GOV pressure solenoid circuit to verify if it's a wiring issue or a burt solenoid. I'm waiting for a replacement PCM to satisfy the trans shop, if that doesn't change anything which I don't think it will, and if I do not have any wiring issues I'm going to have them change all the solenoids and the temp sensor. Unless any of you have any more suggestions or think this is the wrong way to go.



I appreciate all the input.



Thanks again,

Chris

 

[JLandry]

Chris,



If you send me a PM with your email address, I'll send you relevant troubleshooting pages from the Dodge Diagnostic Manual, wiring diagrams from the Service Manual, and connector pin outs. It's way too much stuff to post or attach here. In any case I would definitely completely rule out a wiring problem (a short or open) before I plugged in that replacement PCM just-in-case!



But I'm still baffled by how the transmission can take off in 2nd (or start in 1st and immediately shift to 2nd) when the gear position selector is in 1st. Maybe what I thought I knew about the transmission is all wrong. It's been my understanding that when the gear selector is placed in 1st, this puts the manual shift valve (located within the valve body) in position to physically block hydraulic flow which allow a gear change to 2nd (or higher). Now I'm wondering if that's true.



If I am correct, then could the gear selector linkage simply be out of adjustment so the transmission isn't actually in the gear you think it is? It seems so obvious that it would have been adjusted when the transmission was replaced, but has anyone checked that? The Dodge Service Manual has the adjustment procedure.



Either that, or maybe there's something wrong inside the valve body that isn't readily apparent just by looking at it. After you check and eliminate the wiring harness, sensors, and pressure solenoid, maybe it's time to do a series of comprehensive transmission pressure tests (per the Dodge Service Manual) to verify whether the transmission's hydraulic system is working as it's supposed to.



Best regards,



John L.

 

[Pulice]

John,



I just sent you my address, so let me know if you do not receive it. I do appreciate your insite and have not ruled out your valve body issue. That is a very good point on the shifter linkage. I will definatly check that out today if possible. Amazing how sometimes you can overlook the obvious.



Thanks,

Chris

 

[PToombs]

Chris, FYI, the gov pressure and the trans temp sensor are 1 unit. 4 wires go to it, pins 2,3,4,8 on the trans plug. #2, the orange, 5 volt supply, #3, black/blue, sensor ground, #4, light green/white, gov press signal, and #8, violet, trans temp signal.

Don't be fooled if you have the plug unplugged and check for voltage and find 5 volts on 2,4, and 8. I don't know why, but the sensor leads actually ground thru the #3 wire, and unplugged you get high voltage and a code.

The FSM says that there should be 1000 ohms across the thermister terminals at room temperature. It doesn't say which terminals, temp and ground? Temp and power?



It took me 3-4 evenings of reading the FSM and playing with the truck and the harness and solenoids from the spare trans to figure this out. Having the schematics will help you a lot. If you hit a snag, let us know.

pete

 

[Pulice]

John and Pete,



John you were correct about the linkage, I found that the cross piece between the frame and transmission was loose on the transmission side. I tightned it back up re-adjusted the linkage and got 1st gear manually. However I only get 1st if you select it from "P" or "N". Example: from "P" or "N" stopped place in 1st it takes off in 1st manually shift to 2nd and then 3rd, come to a stop and manually downshift from "D" or "2" and it takes off in 2nd again unless you place the gear selector in "P" or "N" and start over. Anyway thanks for pointing out the obvious John.



Pete thanks for the pin #'s and colors I will try to work on that this week and maybe this weekend, started raining yesterday while I was messing with the linkage, so didn't get much else done.



It's going to take me some time to ohm these wires, solenoids, sensors, and go thru the tests John sent me, but a little time and we all will figure it out. I think we are making progress.



Thanks again for all the help.

Chris

 

[JLandry]

John you were correct about the linkage, I found that the cross piece between the frame and transmission was loose on the transmission side. I tightned it back up re-adjusted the linkage...

Chris,

Glad to hear you're making some progress!

Did you adjust the linkage exactly per the instructions in the Dodge Service Manual?

I ask because it sure sounds like there's still something wrong with the shift linkage. It's as if you're not getting gear position repeatability when manually downshifting from the "D" position to the "1" position. If the linkage is in fact adjusted correctly, maybe something in the linkage is excessively worn or missing... like a bushing maybe?

... it takes off in 2nd again unless you place the gear selector in "P" or "N" and start over.

It sounds like the shift linkage still isn't adjusted properly or has too much slop so that the gear selector level on the side of the transmission isn't actually going into the 1st gear position when you downshift from inside the cab using the gear shift lever.

A way to test this would be to disconnect the shift linkage from the side of the transmission entirely, raise the truck on a lift, then have a helper manually shift the gear selector lever through the different gears while under the truck as you control the throttle and brake inside the cab. I think this test is even mentioned in the Dodge Service Manual.

Now assuming you get the gear shift linkage all straightened out and working properly, *then* we should be able to figure out what else might be wrong with the transmission if it's still not shifting automatically. In the mean time, the gear position problem is a red herring throwing off other trouble shooting tests. I'm amazed the transmission shop didn't eliminate this problem first!

Please keep us posted.

John L.