'05 cant find first gear?

[cerberusiam]

Transmission Throttle Valve Actuator motor is the full description. It is separate from the other trans controls and should not be affected by the harness on the VB, it is the motor bolted to the side of the trans above the shift lever attachment.

Depending on what is actually wrong you may have a VB problem with a sticking regulator valve causing the motor to stop and the TCM to think it is bad.

 

[DFrank]

Yeah, they can't find said ttva.*Anyone have a part number?I amLiterally at the dealer hoping to buy a part that they can't find in the system, *let alone know how to find it in a shelf?Is there an aftermarket one I shouldBe trying?Also planning to add a drain plug next time I drop the pan. Do you have one to suggest?Thanks.*

 

[DFrank]

Thanks! *He did call me.*I've driven the truck back to the front range, limp mode magically cleared out, though the codes won't clear even with dealers scan tool.*I was ready to buy a new ttva, but hey can't seem to find this part in

 

[DFrank]

So this part comes up as auto transmission throttle control lever.*$400+. I'm buying it, but would love to figure out if this is really what I need. I can return it if I decide not to install. Afterwards not so much.*

 

[DFrank]

Can anyone suggest more research to do before replacing the TTva and hoping it solves the problem?The truck is driving, but not shifting well at all. Every time I start out, it feels like it might not make it out of first. Same thing with 2-3, but the it finds OD just fine. When I was driving out of the mountains, I used tow haul to force the down shift on the bigger hills, as the problem first engaged when the truck did it for me. * Interestingly, it found OD itself when it wanted to, even with tow haul still engaged.*Thanks.*

 

[cerberusiam]

Try 53041140AB

 

[DFrank]

Thanks. They did find the part. I have it, and just want to read more about being certain replacing the TTVA is whats called for.

It was $400+

The part is called the auto transmission throttle control lever. Sounds like the older transmission used this part, and the computer still calls it that instead of the TTVA.

 

[DFrank]

So I am replacing the TTVA. Two bolts and it is free, but the plug in wire is being pesky.

I am hesitant to force it and break it.

The little red tab moves about a 1/4" away from the base of the plug, but that doesn't seem to loosen it up.

does that piece just slide to free up the plug, or does it need to be pulled away from the plug to unplug it, if that makes sense.

 

[DFrank]

So after breaking the little plastic tab on the wire end, I swapped out the TTVA.

It didn't seem like the TTVA truly seated over the shaft on the transmission, but I know they were lined up, and it dropped low enough for the bolts to line up, so I assume that part engaged.

I drove it around the block without it finding 2nd. second time I started form a stop, it did find second, the third time not so much.

I hate throwing a $400 part at it and not knowing if the part was even bad.

Any thoughts on what to try next?

Thanks,

 

[DFrank]

So I finally got under there with a volt meter.

I'm not entirely sure I use it correctly, but I think i'm reading two volts on the #5 pin.

I dont see any numbers on the pins; are the two rows number 123, over 456, or is it #1 over 2, 3 over 4 and 5 over 6?

In the first scenario I read 2, or maybe .2? volts at the 5 pin when my kid switches the key to on.

Did I read right, that I could take the TTVA off entirely and the truck would be drivable, just with weird shft points?

With it connected, it is not getting past first gear with any regularity, though the sample is just a cruise around the block.

If I do need an ECU, I read that I needed a VIN coded unit.

The ones I see listed on Ebay are by year for 2500/3500 diesel. Is that enough info, or does it need to be more specific?

Any of the sellers on Ebay, more reputable for these reman units?

Is this a pretty simple plug and play install, or does this get more complicated?

Is there any other testing I can try before biting the bullet on an ECU?

How can I trouble shoot the wires to the TTVA?

Is there a good way to bench test the TTVA I removed? It seems likely that it is a good unit.

Thanks,

 

[cerberusiam]

First thing, are you still getting codes? If you do not have codes for the TTVA it isn't the problem. The signal is PWM signal so a simple DVOM will not read it.

If you broke the locking tab on the plug you will need to zip tie to keep it tight or it will come loose.

The TTVA is plug and play. Install, connect, turn key on for 30 seconds, shut key off. should be good to go.

ECU is VIN locked to truck, you need the correct VIN input and the correct OS loaded for the VIN.

There is no good ECU reman place, they all have issues. Figure on 3 replacements to get it right as a rule. The only sure thing is new and the correct OS level load form Tech Authority. You aren't not at needing an ECU yet.

 

[DFrank]

Thanks. I have not been able to clear the codes, and it just added 1749.

I thought maybe the codes weren't clearing due to my camper batteries being tied in, so I unplugged the camper, and disconnected the batteries negatives.

I know you said to do all of them and ground them out, but the mechanic at the dealer said that was "voodoo" and all I needed to do was disconnect the negatives. I left them off of for 20 minutes air so just now and thats when I reconnected it had the new code.

I am suspicious of this writing harness.

are these still available? I read somewhere that this part had been discontinued.

I also just read about this adjustment bolt, but dont recognize it. Is this inside the pan?

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06-30-2010


Preventing 48RE Transmission Throttle Valve Actuator Codes

Jeff Parlee
Questions? Email Sonnax Tech Support about this article.

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In 2005, Dodge started using a transmission throttle valve actuator (TTVA) instead of a TV cable on the 48RE Diesel 2500 and 3500 Ram trucks. The actuator, mounted to the case above the throttle valve shaft, includes two potentiometers which provide input to the ECM as well as a DC motor that responds to ECM output. The bottom of the TTVA shaft features a D-shaped opening that fits onto the throttle shaft, allowing the actuator to mechanically stoke the TV valve and ultimately control transmission throttle pressure.
There are no adjustments for the TTVA, it must be initialized when replaced or removed and reinstalled on the transmission. Every time the ignition is cycled on, the ECM performs the internal calibration procedure to find the current "zero" position. To initialize the TTVA, the ignition must be held in the "on" position for at least 30 seconds.
During the calibration procedure, the ECM is looking for at least 48 degrees of movement from minimum to maximum span and to establish a minimum range value. Both of these parameters can be affected by the throttle shaft adjustment bolt on the pressure regulator spring retaining bracket. The distance between the bracket and the inside edge of the adjustment bolt head should be .905". A shorter distance will not allow the TV shaft to travel far enough to satisfy calibration parameters and will set a code P1751 and/or P1752.
Here is where you can easily get into trouble. Some of the cable-activated throttle valve brackets have as little as .820" between the bracket and the inside of the adjustment bolt head. Using the cable type bracket set up in a TTVA equipped unit without changing the setting on the adjustment bolt can set the same codes.
Transmission Throttle Valve Actuator Code List:

• P1749 – Transmission Throttle Valve Position Sensor Circuit Low
• P1750 – Transmission Throttle Valve Position Sensor Circuit High
• P1751 – Transmission Throttle Valve Position Minimum Range Performance
• P1752 – Transmission Throttle Valve Span Performance
• P1753 – Transmission Throttle Valve Mechanical Performance
• P1754 – Transmission Throttle Valve Actuator Stuck

• P1755 – Transmission Throttle Valve Control Circuit

A special thanks to Mike Ware of Transware Transmission in Concord, Ontario for his help with the research on this article.

Related Unit(s)

• 48RE

While Sonnax makes every effort to ensure the accuracy of technical articles at time of publication, we assume no liability for inaccuracies or for information which may become outdated or obsolete over time.

 

[cerberusiam]

Which wiring harness?

Yes, the TV adjustment bolt is on the side of the VB in the pan. If it isn't se tin parameter sit messes with the TTVA range. Also, the plunger directly under it is the TTVA pressure valve, it will wear a groove in the control sleeve and jam causing TTVA errors that make it look like the motor is bad. If you are sure the motor is good it is probably time to drop the VB and do some Sonnax repair kits and tweaking to it.

 

[DFrank]

Thanks again.

I am not sure what I've actually fixed, but it is now shifting well.

CEL is still on and the newer code 1749 is still present. The 1751&53 are cleared.

What are the Sonnet repairs you refer to?

This truck has an edge screen on it, thought it supposedly never had the chip or the EGT probe.

I didn't even know it read codes, but I scrolled through its menu and clicked cleared the codes. On the edge all codes are gone. On the odometer it still reads the 1749 and CEL is on.

 

[cerberusiam]

Sonnax has a bunch of repair kits for the VB because they do wear. The one I am referring to is the TV valve repair kit.

 

[DFrank]

Well, truck drives great and all codeshare dissapered for the time being.

I wish I was more confident that I had fixed it vs there being an intermittent issue that will return.

My concern is that the original problem of not finding first gear, may have been intermittent and actually fixed itself before I replaced the transducer and the solenoid, that were throwing codes.

Then it threw more codes and stopped finding the upper gears.

Replaced TTVA due to codes. This didn't fix anything; then the 1749 code got added to the mix.

Maybe I hadn't let the TTVA initialize properly on initial install. Truck was limited to first gear, occasionally finding 2nd.

This AM, I unplugged TTVA. drove the around in first gear.

replugged it in and cycled the key to initialize.

Only then did I realize the Edge computer reads codes and can clear. It cleared out the 1751&3, but not 1749.

Then it drove well, but still had CEL and 1749. 1749 was cleared on the edge, but not the odometer.

One more cycle through clearing codes with the edge, and all codes are gone, and it drives well.

I guess I won't feel confident until I drive this thing up into the mountains and see it handle some hard shifts.

I have a few lingering concerns:
1) I am suspicios of the TTVA wire harness having a possible short.

Also the non supported connection in the oil pan concerns me; I guess this should have been zip tied and is possibly sitting below oil level in the pan.

Service advisor I spoke to said that shouldn't be an issue, but it sounds bad to me.

Thanks again to all who chimed in, particularly Cerb!