P0741 Transmission Rebuild

[300sflyer]

So I now have the dreaded P0741 code. I have had the car to 2 different shops to get their opinions, and both tell me the transmission needs to be rebuilt, as the torque converter is slipping, and the TCC is stuck off. Both quoted about $4K Can to do the job, parts and labour.

I have already repaired lots of other things on this car, including the head gaskets with stud kit, stepper motors in the gauges, all new brakes, new snow tires last year, repaired the sunroof leaks, replaced rear shocks, new wheel bearings, and the list goes on.... And now the transmission needs work... Still drive able at the moment, with no real symptoms showing as of yet, accept for the check engine light.

The car has 215000km on it, and I don't know what to do... Should I just sell it "as is", or part it out for parts, or fix it?

Still in shock, as I really like the car... This is my 4th Bonneville, and have no idea what I would buy next, if that is my best move...

[96 SSEi]

you sound like you love your ride - you may go rebuilt or used - then its much less for labour

never worked on a trans, but others here have replaced the tc. from my understanding - the shift solenoids are the worst cause they buried.

[dougtoth]

That price seems awfully high.
I had my 2000 SLE transmission rebuilt about 13 months ago for $1800.00. (that was parts & labor)
I live outside Milwaukee,Wisconsin and $1800.00 is the going rate around here.
I really like my car and it beats car payments.
I now have 254,000 miles and knock on wood car is running great.
Just 2 more years and I can get Collector Plates for it.
215000km is about 134,000 miles which is low mileage to me.
My 2001 SLE only has 145,000 miles on it. (just a baby)
I guess you will have to weigh the repair cost to a new purchase cost.
If you really like the car I would get it fixed.
I just can't believe the price of $4000.00 to get it fixed.
Good Luck!!!

[CMNTMXR57]

Wholly christ. This has NOTHING TO DO WITH A TRANSMISSION REBUILD!!! Good phucking grief! The shop that told you this should be brought up on some form of fraud charges or fraudulent activity

This code is generated when something isn't right in the TCC circuit. Nothing more, nothing less.

The three main potential possibilities (note not solely, but the bulk of the possibility);
1) Wiring harness is shorting out somewhere.
2) TCC solenoid issue
3) TCM issue.

[300sflyer]

Wholly christ. This has NOTHING TO DO WITH A TRANSMISSION REBUILD!!! Good phucking grief! The shop that told you this should be brought up on some form of fraud charges or fraudulent activity

This code is generated when something isn't right in the TCC circuit. Nothing more, nothing less.

The three main potential possibilities (note not solely, but the bulk of the possibility);
1) Wiring harness is shorting out somewhere.
2) TCC solenoid issue
3) TCM issue.

Now I'm confused...

I've been on the phone, and now have 3 shops tell me it needs a rebuild, and that the torque converter is slipping.... One of them is Mr Transmission. The local shop I took it to, [they came highly recommended] tried to manually turn on the TCC to the looked position, and it did not work. I'm also told the TCC is not accessible without removing the transmission, which means dropping the subframe with the engine and all. The transmission is the 4T80E.

This video seems to suggest a rebuild too. https://www.youtube.com/watch?v=92XzqX1jpgI

[96 SSEi]

I do agree that most mechanics are deceivers and thieves - being smack in the middle of hay fields, the shops in the area will all collude on price and knowledge.
why dont you call around Barrie and see what they say

it wont hurt to follow the cement guy's lead.................look here at the bottom for diagnostics

https://www.obd-codes.com/p0741

[CMNTMXR57]

That link more or less backs up what I posted above.

If the Torque Converter is slipping, that means the TCC solenoid isn't locking up. Not that your transmission is shot and needs to have it's gear box rebuilt. At the most, a new Torque Converter would be needed if it were really "shot". But if it was to that point, your driveability would be crap.

[300sflyer]

Near the beginning of the video, he also talks about damaged or missing seals, causing the torque converter slippage and the P0741 code.

The consensus of all 3 shops I spoke to, was that the transmission has to come out, and given the fact it already has 215000km on it, it would be silly to not rebuild it, and then have other issues with it not too long after that.

[CMNTMXR57]

If seals were damaged, you'd notice that too...

Not dismissing the mileage on it, but why invest that much in something when the fix is probably something simple.

[300sflyer]

The way they explained it, because the whole subframe has to the dropped, the majority of the labour is the re and re of the transmission. Why go just part way when doing the job... they all said.

If the seals were damaged, what symptoms would there be?

Others on the Cadillac Forums, say that if you have code P0741 and code P1860, replacing just the TCC will fix the problem. If you only have the P0741, it will not. It indicates damaged seals.

I still don't know what to do...

[CMNTMXR57]

Here is what GM says;

DTC P0741

Circuit Description
The powertrain control module (PCM) controls the torque converter clutch (TCC) solenoid valve pulse width modulation (PWM). The solenoid controls the hydraulic fluid for TCC apply and release. When the TCC is applied, the engine is coupled directly to the transmission through the TCC. The TCC slip speed should be near 0.

If the PCM detects high torque converter slip when the TCC is commanded ON, then DTC P0741 sets. DTC P0741 is a type B DTC.
Conditions for Running the DTC
• No TP DTCs P0121, P0122 or P0123.

• No VSS DTCs P0502 or P0503.

• No AT ISS DTCs P0716 or P0717.

• No TCC stuck ON DTC P0742.

• No IMS DTCs P1820, P1822, P1823, or P1825.

• No TCC PWM solenoid valve DTC P2763, P2764.

• The engine run time is greater than 5 seconds.

• The time since the gear select lever change is greater than 6 seconds.

• The IMS indicates D2, D3 or D4.

• The transmission gear ratio indicates 2nd, 3rd or 4th gear.

• The transmission fluid temperature is 20-133°C (68-271°F).

• The TP angle is 10-50 percent.

• The engine torque is 43-215 N·m (32-159 lb ft).

• The TCC solenoid valve is commanded ON.

Conditions for Setting the DTC
TCC slip speed exceeds its limit for a given torque for 5 seconds.

Refer to Torque Converter Clutch Slip Speed .

Action Taken When the DTC Sets
• The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.

• The PCM inhibits 4th gear if the transmission is in hot mode.

• The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.

• The PCM stores DTC P0741 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC
• The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.

• A scan tool can clear the MIL/DTC.

• The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.

• The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids
• Inspect the transmission fluid level.

• The transmission may be in hot mode. Inspect the transmission fluid lines to the radiator. The lines may be pinched, plugged or twisted.

Test Description
The numbers below refer to the step numbers on the diagnostic table.

2) This step inspects the transmission fluid to ensure that it is at the proper level.

3) This step verifies that the TCC engages when commanded ON by the scan tool.



1) Did you perform the Diagnostic System Check - Engine Controls?
--
Yes: Go to Step 2
No: Go to Diagnostic System Check - Engine Controls in Engine Controls - 4.6L

2) Did you perform the Transmission Fluid Checking Procedure?
--
Yes: Go to Step 3
No: Go to Transmission Fluid Check

3) Install a scan tool.
- Turn ON the ignition, with the engine OFF.

Important: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the PCM.

-Record the DTC Freeze Frame and Failure Records.
-Clear the DTC.
-Drive the vehicle at 72 km/h (45 mph).
-Using the scan tool, command the TCC PWM solenoid valve ON.
-Operate the vehicle under the following conditions:
• The transmission fluid temperature (TFT) is 20-133°C (68-271°F).

• The engine torque is 43-215 N·m (32-159 lb ft).

• Drive the vehicle in D4 with a throttle position (TP) angle of 10-50 %.

• Ensure that the TCC applies for more than 5 seconds.

-Monitor the TCC slip speed.
During TCC application, is the slip speed within the specified parameters?
Specified Parameters -20 to +100 RPM

Yes: Go to Diagnostic Aids
No: Go to Step 4

4) During TCC apply, if NO change in TCC slip speed inspect for the following conditions:
• The TCC control valve is stuck OFF due to sediment or binding.

• The TCC regulator valve is stuck OFF due to sediment or binding.

• The TCC feed valve is stuck OFF due to sediment or binding.

• The TCC enable valve is stuck OFF due to sediment or binding.

During TCC apply, if SOME change in TCC slip speed, inspect for the following conditions:
• The TCC PWM oil pressure screen is clogged.

• The TCC PWM solenoid valve O-ring is leaking or cut.

• Refer to Control Valve Upper Body Disassemble in the 4T80-E section of the Transmission Unit Repair Manual.

• The turbine shaft seal, case cover to turbine shaft seal, case cover to drive sprocket seal and drive sprocket support are worn.

• Refer to Torque Converter and Oil Pump Drive Shaft Removal and Drive Sprocket, Driven Sprocket, and Drive Link and Assemble in the 4T80-E section of the Transmission Unit Repair Manual.

Repair any of the above items as necessary.
If no problems found in previous conditions, replace the T/C viscous clutch.
Did you complete the repair?
--
Yes: Go to Step 5
--

5) Perform the following procedure in order to verify the repair:

Select DTC.
Select Clear Info.
Operate the vehicle under the following conditions:
• The TFT is 20-133°C (68-271°F).

• The engine torque is 43-215 N·m (32-159 lb ft).

• Drive the vehicle in D4 with a TP angle of 10-50%.

• Ensure that the TCC applies and the slip speed is -20 to +100 RPM for 4 seconds.

Select Specific DTC.
Enter DTC P0741.
Has the test run and passed?
--
Yes: Go to Step 6
No: Go to Step 2

6) With the scan tool, observe the stored information, capture info. and DTC info.

Does the scan tool display any DTCs that you have not diagnosed?
--
Yes: Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 4.6L
No: System OK

Please understand that while the trans will need to be dropped (which includes the subframe dropping... Which is where the cost will come in), neither of those repairs in Step 4 are "complete rebuilds" as these shops are telling you and as I lashed out originally.

[300sflyer]

Understood... Thanks for the info!

Unfortunately, I do not own a high end scanner, so I am at the mercy of the repair shops. Most of them won't even allow customers into the service bay while their car is being worked on, due to insurance regulations, so ensuring everything is done by the book, is almost impossible. Finding a shop that is trustworthy, is pretty darn hard these days!

[96 SSEi]

with all the $ you save, you can get a 150-200 buck actron that will suit your needs. who knows, with the help of the ex gm techs here, you may repair it yourself!!

[300sflyer]

I would be very surprised if a $200 scanner has the ability to force the TCC into the on position. The one I have now won't. In addition, I do not have access to a hoist, which is a necessity to drop the subframe.

[300sflyer]

Just for $hits and giggles, I put a bottle of Lucas transmission conditioner in it. It wasn't long before the code came right back once at 45 mph.

[96 SSEi]

I would be very surprised if a $200 scanner has the ability to force the TCC into the on position. The one I have now won't. In addition, I do not have access to a hoist, which is a necessity to drop the subframe.

there is no drop s-frame in the service post - why are you hung-up on the dropping - check the wiring first - follow very professional looking instructions and you may have joy.

[300sflyer]

I would be very surprised if a $200 scanner has the ability to force the TCC into the on position. The one I have now won't. In addition, I do not have access to a hoist, which is a necessity to drop the subframe.

there is no drop s-frame in the service post - why are you hung-up on the dropping - check the wiring first - follow very professional looking instructions and you may have joy.

The TCC and its wiring/connector are located inside the side cover of the transmission. Hence the requirement to drop the subframe/transmission in order to access to them.

[CMNTMXR57]

I would be very surprised if a $200 scanner has the ability to force the TCC into the on position. The one I have now won't. In addition, I do not have access to a hoist, which is a necessity to drop the subframe.

there is no drop s-frame in the service post - why are you hung-up on the dropping - check the wiring first - follow very professional looking instructions and you may have joy.

There actually is, you have to remember in the actual service program I get this from, there are links that don't get copied in a copy and paste unfortunately. This program isn't user friendly in terms of extracting information, particularly useful pictures.

In step 4;

Refer to Control Valve Upper Body Disassemble in the 4T80-E section of the Transmission Unit Repair Manual.

and

Refer to Torque Converter and Oil Pump Drive Shaft Removal and Drive Sprocket, Driven Sprocket, and Drive Link and Assemble in the 4T80-E section of the Transmission Unit Repair Manual.

Both link to a service procedure, which in order to do, requires the transaxle being removed from the car, which requires subframe dropping.

[300sflyer]

Both link to a service procedure, which in order to do, requires the transaxle being removed from the car, which requires subframe dropping.

Here is a video showing its removal, without dropping the subframe. https://www.youtube.com/watch?v=gtOvzj4rEBE Granted this is in Cadillac, but the basics should be the same.

What do you think the chances are that just changing the TCC, would solve the problem?

[CMNTMXR57]

It can be done. Problem is, sometimes it doesn't work that easy as the video looks. I would imagine that there is some cutting/editing because I'm sure lots of expletives were used.

It could work. Not going to give a 100% case solved without following the diagnostics in step 3 and 4 above. But knowing you don't have access to the scan tool, Again "it could work".