Transmission Stuck in 4th Gear

[Ludville1]

Driving home today trans. is stuck in 4th, won't upshift or downshift, manually or automatically. Any ideas?

 

[Sillygoose]

that's the limp mode gear. should come out of it if you shut it down/restart.

 

[Ludville1]

that's the limp mode gear. should come out of it if you shut it down/restart.

What would cause the truck to go into limp mode?

 

[RamDiver]

What would cause the truck to go into limp mode?

Much more than a couple of reasons.

This might be a good time to scan for DTC codes. If you don't have a scanner, many automotive parts stores will scan for free.

.

 

[Ludville1]

Sounds like the shift solenoid is a common problem on these trucks.

 

[Ludville1]

Actually put my scanner on the truck and got code PO841...trans. fluid pressure sensor. Looks like an easy fix...$30 part. Hopefully that takes care of it.

 

[RamDiver]

Actually put my scanner on the truck and got code PO841...trans. fluid pressure sensor. Looks like an easy fix...$30 part. Hopefully that takes care of it.

Please keep us posted. TIA

.

 

[Ludville1]

Well, the new transmission fluid pressure sensor came in the mail today from Rock Auto. About a 10 minute repair, and the truck shifts great! What a relief! Really freaked me out when the truck went into "limp mode" - stuck in 4th gear. Never knew of such a thing.

 

[gounc82]

Where is the location of the sensor? I’m having the same problems

 

[GTyankee]

gounc82
get the Ram scanned for codes
2009 Dodge Ram & yours use completely different transmissions
A German company makes the transmissions for 2013 & up Rams

 

[Ludville1]

Been having to do some repairs lately to the '09 Ram. 4WD actuator, transfer case output shaft seal, and now the transmission fluid pressure sensor. To be expected on an old truck with 162,000 miles on it though. Luckily, the parts have been relatively cheap, and I have been able to do the repairs myself. However, I do still love this old truck! Paid cash for it back in 2018. Truck still looks almost new inside and out, and is not driven in the Winter time. Rear end was rebuilt before I got it, I had the transmission rebuilt shortly after buying it, and the engine still runs really strong and quiet, and it's a beast!

 

[Ludville1]

Where is the location of the sensor? I’m having the same problems

Yeah, my transmission is the 545RFE 5 speed.

 

[Ludville1]

So after singing high praises about my old Ram, coming home tonight the trans. downshifted into 4th again and stayed there. It is showing code P1776 now. Might be a shift solenoid after all.

 

[Dusty]

On 545RFEs of that vintage you likely have a sticking Solenoid Switch Valve or a weak TRS solenoid. You can replace the TRS assembly separately from the valve body, but if I had to guess the problem is either a dirty valve body, worn shuttle valve or valve ports, leaky solenoid seals, or a leak in the separator plate.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 101293 miles.

 

[Ludville1]

On 545RFEs of that vintage you likely have a sticking Solenoid Switch Valve or a weak TRS solenoid. You can replace the TRS assembly separately from the valve body, but if I had to guess the problem is either a dirty valve body, worn shuttle valve or valve ports, leaky solenoid seals, or a leak in the separator plate.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 101293 miles.

Thanks for your input, exactly what I was hoping for!

 

[Dusty]

Thanks for your input, exactly what I was hoping for!

I should've mentioned to first check the electrical connections going to the transmission, especially at the TRS connector.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 101313 miles.

 

[Ludville1]

I should've mentioned to first check the electrical connections going to the transmission, especially at the TRS connector.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 101313 miles.

Great idea, easy enough to do...thanks!

 

[Ludville1]

I should've mentioned to first check the electrical connections going to the transmission, especially at the TRS connector.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 101313 miles.

And it does seem to be an intermittent problem. After changing the trans. fluid pressure sensor and clearing the code PO841 it seemed fine. I then drove the truck 20 miles to my cabin and then when I was almost back home, the truck went into limp mode...was fine prior to that. And yesterday took it for a little ride, then to town and back to get gas, no issues. Also, a little while back, after replacing the transfer case output shaft seal, I sprayed the transmission, transfer case, and under carriage down with engine degreaser, simple green, then rinsed with water to clean up the trans. fluid from the leaking transfer case seal that sprayed all over everything. Maybe something got into the TRS connector? I will check it out. The transmission was professionally rebuilt only 12,000 miles ago, so I would think internally the trans. should be quite clean, it looks clean on the dip stick at least. Also, both times that the truck went into limp mode, I was on the way back home from my cabin (20 miles each way).

 

[Dusty]

And it does seem to be an intermittent problem. After changing the trans. fluid pressure sensor and clearing the code PO841 it seemed fine. I then drove the truck 20 miles to my cabin and then when I was almost back home, the truck went into limp mode...was fine prior to that. And yesterday took it for a little ride, then to town and back to get gas, no issues. Also, a little while back, after replacing the transfer case output shaft seal, I sprayed the transmission, transfer case, and under carriage down with engine degreaser, simple green, then rinsed with water to clean up the trans. fluid from the leaking transfer case seal that sprayed all over everything. Maybe something got into the TRS connector? I will check it out. The transmission was professionally rebuilt only 12,000 miles ago, so I would think internally the trans. should be quite clean, it looks clean on the dip stick at least. Also, both times that the truck went into limp mode, I was on the way back home from my cabin (20 miles each way).

A tech. friend of mine has told me that on older vehicles about 50% of intermittent transmission problems are electrical. On RFE series the TRS connector can be the primary source of trouble since it is greatly exposed to the elements.

One of my son's had a '06 Ram 1500 where we found green crusties in the TRS connector pins, but if do a web search you'll find that anywhere in the transmissions circuits from PCM down there could be a problem.

They improved the TRS connector seals along the line and I think you're '09 probably has it. Still, it's worthy of checking and easy to get to. Which reminds me, like GM L-series they can leak ATF from the inside out as well.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 101318 miles.

 

[Ludville1]

A tech. friend of mine has told me that on older vehicles about 50% of intermittent transmission problems are electrical. On RFE series the TRS connector can be the primary source of trouble since it is greatly exposed to the elements.

One of my son's had a '06 Ram 1500 where we found green crusties in the TRS connector pins, but if do a web search you'll find that anywhere in the transmissions circuits from PCM down there could be a problem.

They improved the TRS connector seals along the line and I think you're '09 probably has it. Still, it's worthy of checking and easy to get to. Which reminds me, like GM L-series they can leak ATF from the inside out as well.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 101318 miles.

Thank you sir, I do plan on checking the TRS connector soon. Can't hurt.