Cadillac STS Transmission Problems & Cost | 5L40E | 6L50

Introduced for 2005, the Cadillac STS was not the brand’s flagship model. But it was the most expensive car in their lineup. V6, V8 and supercharged V8 powerplants were offered, along with a host of state-of-the-art (at the time) features. It wasn’t exactly a sales success, but it was one of the most advanced Cadillac’s in its day. Part of what made it so advanced were the five and six-speed automatic transmissions, which was still relatively new technology at the time. But like many cutting edge things, issues can arise. So let’s look at some of the most common Cadillac STS transmission problems, and figure out what you can do about them.

Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.

What Transmission Do I Have?

Cadillac STS Transmission Models

Cadillac STS: 5L40E Transmission

Cadillac STS: 5L50E Transmission

Cadillac STS: 6L50E Transmission

Cadillac STS Transmission Replacement Cost Estimate

Pricing varies by model. To be 100% sure on pricing, have your VIN# handy and use our Get An Estimate feature to look up your transmission by VIN#.

Replacement Cadillac STS Transmission Prices:

TransmissionStreet Smart TransmissionAutozoneAdvance Auto PartsDealer Retail
5L40E (Exc. BMW)2122214521993618

What are the DTC codes related to Cadillac STS transmission problems?

Trouble CodeDescription
P0711Transmission Fluid Temperature Sensor Circuit Range/Performance
P0712Transmission Fluid Temperature Sensor Circuit Low Input
P0713Transmission Fluid Temperature Sensor Circuit High Input
P0714Transmission Fluid Temperature Sensor Circuit Intermittent P0715
P0715Input/Turbine Speed Sensor Circuit
P0716Input/Turbine Speed Sensor Circuit Range/Performance 
P0717Input/Turbine Speed Sensor Circuit No Signal
P0718Input/Turbine Speed Sensor Circuit Intermittent
P0720Output Speed Sensor Circuit
P0721Output Speed Sensor Circuit Range/Performance
P0723Output Speed Sensor Circuit Intermittent
P0729Gear 6 Incorrect Ratio
P0730Incorrect Gear Ratio
P0731Gear 1 Incorrect Ratio
P0732Gear 2 Incorrect Ratio
P0734Gear 4 Incorrect Ratio
P0735Gear 5 Incorrect Ratio
P0740Torque Converter Clutch Circuit Malfunction
P0741Torque Converter Clutch Circuit
P0742Torque Converter Clutch Circuit Stuck On
P0744Torque Converter Clutch Circuit Intermittent
P0748Pressure Control Solenoid 'A' Electrical
P0750Shift Solenoid 'A'
P0753Shift Solenoid 'A' Electrical
P0755Shift Solenoid 'B'
P0758Shift Solenoid 'B' Electrical
P0767Shift Solenoid 'D' Stuck On
P0850Park/Neutral Switch Input Circuit
P0897Transmission Fluid Deteriorated
P0973Shift Solenoid “A” Control Circuit Low
P0976Shift Solenoid “B” Control Circuit Low
P0977Shift Solenoid “B” Control Circuit High
P0979Shift Solenoid “C” Control Circuit Low
P0980Shift Solenoid “C” Control Circuit High
P0982Shift Solenoid “D” Control Circuit Low
P0983Shift Solenoid “D” Control Circuit High
P0984Shift Solenoid “E” Control Circuit Range/Performance

Cadillac STS Transmission Recalls

None Found

Cadillac STS Technical Service Bulletins (TSB)

TSB 02-07-30-026 – Transmission shudder during hard acceleration – Cadillac STS 5L40E 
Problem – During hard acceleration, it is not uncommon for the transmission to shudder/shake after launch. This is caused by insufficient clearance between the driveshaft attaching bolts and the transmission output shaft flange.
Solution – Install a revised transmission output shaft flange.

TSB 07-07-30-032B – Ignition key sticks, shifter binds, “shift to park” message displayed, dead battery – 5L40 Transmission | 5L50 Transmission | 6L50 Transmission | 6L80 Transmission
2007 – 2008 Cadillac SRX – 2007 – 2008 Cadillac STS – 2007 – 2008 Cadillac STS-V – 2008 Cadillac CTS
Problem – Owners may notice that the shifter seems to bind when shifting into gear or park. The ignition key may stick or be difficult to remove (SRX only). A “shift to park” message may be constantly displayed in the driver information display screen, resulting in a dead battery.
Solution – These transmission problems may be caused by out of adjustment shift linkage, a slow Brake Transmission Shift Interlock mechanism, or a Park Confirmation microswitch that is not closed.

TSB PIP4570B – Erratic torque converter clutch operation, metallic debris in the oil pan, and/or P0741, P0751 DTC – 6L50 Transmission
2008 – 2009 Cadillac CTS – 2008 – 2009 Cadillac SRX – 2008 – 2009 Cadillac STS
Problem – Drivers may notice erratic torque converter operation, which can include erratic shifting and unexpected engine stalling.
Solution – These 6L50 transmission problems can be caused by de-bonding of the TCC friction material. This can lead to internal transmission damage, possibly requiring a transmission rebuild or remanufactured transmission. At the very least the torque converter itself may need to be replaced.

Common Problems with the Cadillac STS Transmission

No forward or reverse engagement with grinding noise on initial start-up – Cadillac STS 6L50 
Problem – All wheel drive equipped cars with transfer case model BW44-77, can experience a grinding noise and no forward or reverse gear engagement on initial take off. This is caused by rust damage to the transmission output shaft and transfer case input shaft, due to a lack of lubrication.
Solution – Install new transfer case input shaft and updated transmission output shaft, which has a special O-ring to trap lubricant in the splind area.

Lack of Response
Leaking Fluid
Low Fluid
Burning Smell
Grinding or Shaking
Whining, Clunking or Humming
Refuses to Go Into Gear
Torque Converter Issues
Valve Body Issues
Transmission Noisy in Neutral
Gears Slipping
No 3rd or 4th Gear
No 1st or 2nd Gear
No Reverse
Dragging Clutch
Trouble Codes / Check Engine Light

Can I drive with a transmission problem?

Obviously, not all Cadillac STS transmission problems will make the car undrivable. But continuing to use the car when the transmission is not working properly, can cause other components to wear out or fail prematurely.

How often does a Cadillac STS transmission need to be replaced?

As long as it is maintained properly, a Cadillac STS transmission can last for a very long time. Of course, factory design flaws and driving style do factor into the service life. But on average, we found an STS transmission can last between 130,000-180,000 miles. A correctly built remanufactured transmission however, can last considerably longer. Provided all of the OE design flaws are addressed.

How are Cadillac STS transmission issues diagnosed?

To figure out what’s actually causing your Cadillac STS transmission problems, a technician will need to connect a scan tool to the car’s OBDII port. This will allow them to read all of the trouble codes, so they can determine which components they need to inspect. Driving the vehicle may also be necessary to replicate the conditions in which the fault occurs.

How is a Cadillac STS transmission replaced?

Because the Cadillacs STS is a rear wheel drive vehicle, replacing the transmission is fairly simple. The driveshaft will have to be removed, along with other components (like the exhaust system) that may be in the way. Installation is a reverse of the removal process, but the ECU / PCM will have to be reprogrammed / reflashed to accept the new transmission using the latest GM subscription.

Recommendations for Cadillac STS transmission issues?

To save time and get back on the road faster, have your 17-digit truck VIN# handy and you can get an online quote for a reman Cadillac STS transmission here, then find a local shop using our Find a Shop guide to install it for you.

How to Solve Cadillac STS Transmission Problems

Solution A: Buy a Used Cadillac STS Transmission

Since money doesn’t exactly grow on trees, you might be tempted to go to the local junkyard and buy a used 5L40E / used 5L50E / used 6L50E transmission. They are relatively affordable, and most will come with a 30-90 day warranty. However, it is hard to know the exact condition of the internal components, so you may have the exact same problems in the near future. And that junkyard warranty probably won’t cover labor charges to fix or replace that used Cadillac STS transmission.

Solution B: Buy a Rebuilt Cadillac STS Transmission

The next most logical idea would be a rebuilt 5L40E / rebuilt 5L50E / rebuilt 6L50E transmission. Most of the time, a mechanic will take your existing gearbox, and fit it with a bunch of OE spec Cadillac STS transmission parts. This is all well and good, in theory. But taking your transmission back to the original specifications, means that all of the common failure points will be there to fail again. And that rebuilt transmission warranty may only be honored by the shop that built it. So you’ll have to pay for repairs out of pocket, if you have a breakdown while you are traveling.

Solution C: Buy a Remanufactured Cadillac STS Transmission

To get the most life out of your Cadillac STS, you may want to consider getting a remanufactured 5L40E / remanufactured 5L50E / remanufactured 6L50E from a reputable supplier. These are often upgraded to compensate for common failure points, and a nationwide warranty will allow you to be protected from transmission repair bills when you travel.

Need a replacement transmission? Get an estimate for replacement transmissions and local installation. Look up your transmission model by vehicle make and model.

What Transmission Do I Have?

What Problem Does Your Cadillac STS Have?

Let us know the year, mileage and problem you’re having as well as any trouble (OBD) codes you’ve found. If you’ve been given a quote or paid for a repair, we’d like to hear about that too!

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3 months ago

My mileage is only at 99k also I forgot to post it in last comment

3 months ago

I got a 2003 Cadillac Seville sts no codes are coming up no service engine light is coming up just low oil pressure shut off engine now keeps poppn up and havnt changed oil because I just got it back from tow yard after sitting for 2 years but I got in car and reversed and the car stopped as if the emergency break was on i hit the gas and all it did was rev no movement put it in drive and it moves forward put it in nuteral it wont move left it for couple days dropped pan and refilled her put it in reverse and it moved but car was jerking and whole engine bay was shaking but it reversed I put it in drive and it drove 2 weeks without no problems except now there was a whining noise coming from front of car it quit after 4 days and only whined until i got up to 40mph then stopped not the whining has dissapeared but the tranny is slippn when engine reaches temp at the red light 5mins into driving it the light turned green I hit gas and its struggling to get going lets just say I had to run a couple red lights outta fear of the car not wanting to go if i did end up stopping again and the day before that it just quit driving and would rev when I got home in my driveway smoke was coming from under hood I dropped pan and found a couple good size metal chunks in pan and pan was covered with silver metal shavings and yellow plastic pieces looked like human teeth kinda it was weird and it was making a noise as if something was grinding together crunching need help with this idk what else to do

Jonas mouton
6 months ago

Not shifting after 3rd gear an makes a kinda grinding noise

John. Husk
8 months ago

Car seems to jerk when slowy Accellerating at normal speedd

Robert Kirk
8 months ago

The transmission is stuck in drive in all shifter positions except for sport manual mode

Denzel Rogers
9 months ago

What Does it mean when you put your car in drive in gear without pressing the break

Robert Kirk
9 months ago

I have a 05 sts everything works in all the forward gears but It don’t even try to grab reverse

1 year ago

It hesitate when I hit the gas

1 year ago

Its stalls when I make a turn and some times it feels like it struggles to shit in 2nd gear

Michelle aydnor
1 year ago

I have a 2006 Cadillac sts I believe it’s awd 3.6 v6 motor but it was having trouble shifting from 4 to 5 gear and then it just stopped all together one day going down the road and wouldn’t go any further. Until I stopped the car all together turned it off and started it back a few minutes later and it went into gear just fine and it has continued to do this thing for the past week I finally parked it but I wanted to know if there was anything else I could try besides replacing the whole transmission because that can be pretty costly

1 year ago

When put in reverse it try to pull forward and backward to at same time

1 year ago

When put in reviews it try’s to pull forward to

2 years ago

Car will not go past 2nd gear and no light on. Just replaced fuel injector

2 years ago

Crank no start getting fire and getting gas

3 years ago

2005 caddilac sts nocking at idle but when I restart it no nocking

3 years ago

My 2005 Cadillac STS has about 156000 miles when put in gear it makes a loud thump noise now it started. Making a grinding noise under hood when I drive it the check engine light turns on when noise starts sometimes noise will stop and light turns off also but sometimes grinding noise remains by light starts blinking

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