My CRD is still a bit new to me (less than a month), but I discovered an issue that only happens if you manually put the transmission selector in 2nd gear.

First the background. I have 2005 CRD I purchased from a member on this forum that was well setup and one of the things he did was put in a used Dodge Ram Transmission with 38k miles (maybe 2-3k miles ago) including the Torque Converter from the Dodge Ram, also did the Trans Go Shift kit and the PML Deep sump trans pan all at the same time. It sounded like while he was in there he did everything you would to make sure everything was in great shape inside the transmission. It does have the GDE ECO & HOT ECM Tunes, but as far as I know the TCM is stock with no tune from the way it shifts. Just for reference, I have a Dodge Ram TCM I received with the truck and I've duplicated the issue with that one, but I didn't like it so I put the stock one back on. I do plan on getting the GDE TCM tune, but I thought maybe I should figure out what is causing this issue first?

First off the transmission shifts great in normal driving mode in D with OD button on/off. It shifts from a stop through all 5 gears no issues, kicks down to 2nd no problem if you force a kick down with the throttle, locks/unlocks in 3rd, 4th, & 5th gears as expected, downshifts as you expect when coming to a stop. Basically there is nothing to lead you to think there is any issue at all and the transmission shifts as smooth as you could expect. I can also put the trans in 1st gear and it does just fine and holds the transmission in 1st gear as you expect. The problem occurs when you put the selector in 2nd. At that point something goes wrong and the transmission goes into limp mode and throws two codes (P0700 - Generic Transmission error) & (P0871 - Transmission Fluid Pressure Sensor/Switch "C" Circuit Range/Performance).

If you are accelerating from a stop with the trans in 2nd. It will start off in 1st, shifts to 2nd and then immediately hits another gear. I can't be certain what gear it's hitting, but it's going to a higher gear. With the trans selector in 2nd, it should be holding the lower 2nd gear and not going any higher. The 545RFE is not supposed to shift consecutively between the two different second gears so I doubt it's doing that. I suspect that it's actually going to 3rd gear, but obviously that isn't right either if the selector is in 2nd. (Maybe that's the fail safe limp mode when the codes get thrown?) From that point on with the transmission in limp mode and the CEL set, it stays in that gear (3rd maybe) and won't downshift or up shift. If you stop, it takes off in that high gear and won't shift at all. Even if you move the lever to 1st, it doesn't force it to shift any more at that point.

I've also done it the other way if you were coming down a steep hill and needed more engine braking and shift from 3rd (O/D) off into 2nd. It hit's 2nd gear for a split second, then up shifts and throws the code and gets stuck in that 3rd gear.)

For some reason it seems to be a bit of a fight to get the code to clear and get things back to normal too. I've tried both with the GDE Tuner (which is the faster way) or a basic ODBII BT module and the Torque app. Usually it takes about 4-6 times of clearing the code before it finally actually clears the CEL and it doesn't pull back any codes. I've tried different things but it's usually takes a bit of fiddling to get it done. Once the codes are clear, the transmission goes back to shifting like normal as long as you don't put it in 2nd.

Since I know what causes it, I'm obviously trying not to do it and it's easy to avoid, but I could definitely see times it would be nice to have that manual 2nd gear working as expected when I need that engine braking or maybe playing off road or something.

This thread viewtopic.php?f=5&t=80776&p=850906&hilit=p0871 specifically mentions the P0871 code and about the sensor, but not much else was really gone into about it other than where it's located. I would think if there was an actual sensor issue, I would get it all the time even in normal driving, but this only happens when the selector is in 2nd gear?

I've owned way more manual transmission cars than auto transmissions and honestly wish the CRD came in a manual, but I had to concede and accept the fact that if I got one, it would be an auto. So my knowledge on auto transmissions is pretty limited.

I did find this chart while searching the issue. Could there really be something different happening when the selector is in 2nd gear vs when the transmission is just normally shifting through 2nd gear while in D?

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2005 Liberty for sale - viewtopic.php?f=35&t=86570
05 Liberty CRD - GDE Eco/Hot Tune, ARP studs, Weeks EGR/FCV delete, Flowmaster DBX muffler, HDS Thermostat
00 VW Beetle TDI - Stock
11 Mini Cooper - Wife's
Motorcycles:: KTM 650 ADV (Katuki), 05 BMW 1200GS, 08 Yamaha WR250R

Not really sure how it works on the transmission, but is it possible that the gear selection linkage and an internal indicator switch are not both in the 2nd gear position? I know people have this issue with the transfer case position switch

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2006 CRD - GTB2056 turbo by Dieselguy86, Eco Trans Tune, Lift Pump, Week's, HDS Tstat, Racor Filter, ARP's, OME 790's+Top Plate, JBA 2.5", JBA UCA, Moab's+265/75R16, ARB Bull Bar, 4.10's, TrueTracs

I suspect a problem within valve body. Specifically the manual valve.
The manual valve is the part that actually connects to the shift linkage.
It could be that the valve is mis-aligned or worn, causing some pressure to leak past and forcing the shift into 3rd and causing limp mode.

Did the previous owner install the TransGo shift kit?

I dont think the shift kit does anything for the manual valve
But the kit could effect the line pressure sensor if installed incorrectly.
The line pressure sensor (aka pressure transducer) is on the passenger side near the rear, just above the pan.
The pressure sensor is the easiest part to change if you want to try that first.
http://www.cascadetransmissionparts.com/45rfe545rfe.aspx has all the parts
You might want to also consult them about your problem to see if they have any better advice.

I manually select 2nd gear a lot. Mainly because the trans doesn't always downshift when I feel it should. I havent encountered this problem you describe.

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U.S. Army Retired

Yes, the previous owner did all the work including swapping the Transmission, Torque Converter, and putting in the TransGo shift kit.

The sensor would be somewhere to start perhaps, but would there be any difference between the TCM telling it shift through 2nd gear (which it does fine) vs having the lever in 2nd? Maybe there are higher line pressures when you manually have it in 2nd gear?

If it's the manual valve in the valve body that is worn, what does it entail to fix/replace that?

_________________
2005 Liberty for sale - viewtopic.php?f=35&t=86570
05 Liberty CRD - GDE Eco/Hot Tune, ARP studs, Weeks EGR/FCV delete, Flowmaster DBX muffler, HDS Thermostat
00 VW Beetle TDI - Stock
11 Mini Cooper - Wife's
Motorcycles:: KTM 650 ADV (Katuki), 05 BMW 1200GS, 08 Yamaha WR250R

I would think that it would require replacement of the entire valve body.
But it could be something else. Contact cascadetransmissionparts.com to see what they think.

After looking through the flow diagrams in the service manual, there seems to be a solenoid thing (labeled MS) that is open when the selector is 2nd. This solenoid is also inline with the line pressure sensor.
So I suppose if that the solenoid is faulty this could be causing your problems.
The solenoid pack can be replaced separately from the valve body.

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U.S. Army Retired

Thanks, hopefully that gets me going in the right direction!

_________________
2005 Liberty for sale - viewtopic.php?f=35&t=86570
05 Liberty CRD - GDE Eco/Hot Tune, ARP studs, Weeks EGR/FCV delete, Flowmaster DBX muffler, HDS Thermostat
00 VW Beetle TDI - Stock
11 Mini Cooper - Wife's
Motorcycles:: KTM 650 ADV (Katuki), 05 BMW 1200GS, 08 Yamaha WR250R