: P0101 and P0741 -2000 Deville



00 Deville
03-22-11, 11:01 AM
I have had the SES light in my 2000 Deville come on 3 times in the last 3 months. Immediately pulled the codes and had the following...

12/08/10
P0101 MAF Performance (current)
P0741 TCC Stuck Off (current)

12/20/10
P0101 MAF Performance (current)
P0741 TCC Stuck Off (current)
-Swapped MAF and ductwork from TB to airbox with my 02 Deville
-Replaced Plenum (cracked)
-Did a drain and fill of transmission fluid to new Dexron VI

01/17/11
P0101 MAF Performance (current)
P0741 TCC Stuck Off (current)
-Fixed a couple of small vacuum leaks (PCV valve cover grommet & a poor fitting vacuum line)


I found it odd that each of the 3 times the SES light came on I had both the P0101 and the P0741 set as current. I was hoping that the P0101 was somehow causing the P0741 to trip also. After searching this forum I could find no occasions of the these 2 codes being related in other posts. After reading the FSM I found this interesting...

-The 1999 Deville FSM states in the conditions for running DTC P0741... "No MAF DTC's P0101, P0102, or P0103" (set)

-The 2000,2001,2002 Deville's FSM in the conditions for running DTC P0741... makes no mention of any MAF codes (DTC's P0101, P0102, or P0103) inhibiting the P0741 from being set.

-The 2003 Deville FSM states in the conditions for running DTC P0741... "No MAF DTC's P0101, P0102, or P0103" (set)

Could this be possible that a P0101 code is or was tripping the P0741 or am I just off my rocker hoping the 2 are related??? :hide:

I haven't had either code trip since repairing the 2 small vacuum leaks back on 01/17/11. My plan before my HG recently failed was to have the dealer update my PCM software for a TSB that effects the 2000 N* to eliminate nuisance P0101 codes (they loosened the parameters that trip the code) if the codes reappeared. Since the engine will be coming out of my car soon should I try to replace any parts for the P0741 and if so what?

Thanks in advance for any advice or if just want to tell me that I'm a freak'in genius or I've lost my mind thinking these 2 codes are somehow related...

Ranger
03-24-11, 01:36 AM
Logically speaking I don't see any relationship between those two codes. Can't explain the FSM though. That's strange.

mhamilton
03-24-11, 11:44 AM
I don't think there is any relationship. The 741 is based on slippage % between the trans input and output.


Since the engine will be coming out of my car soon should I try to replace any parts for the P0741 and if so what?

Perfect time to fix that. The P0741 by itself indicates the seals between the trans and torque converter have started to leak and TCC lockup is slipping. Somewhere here in this forum is a thread on that job. If I remember, the seals and the torque converter bearing get replaced. Then you also have to replace the torque converter itself. And while you have the trans open, replace the TCC solenoid ($20) just for insurance against a future failure.

00 Deville
03-24-11, 02:45 PM
I don't see any relationship between the 2 either... but, why would the PCM software engineers inhibit a P0741 code when a P0101 is present on the 99 and earlier and the 03 and later unless there was some relationship between the 2 that where not seeing. :hmm: Then allow a P0741 to trip with a P0101 being present on the 00-02's assuming the FSM 's are correct.

mhamilton, Thanks... I do have a copy of the TSB that deals with the P0741 and the leaking seals. I just wish I had more time to experiment with testing a few theories before the cradle is dropped. What part of NC do you call home?

mhamilton
03-24-11, 03:14 PM
Not sure what their thinking was. Maybe if a MAF error is present the PCM inhibits lockup or something (since it might be getting inaccurate engine load information). But if you have the 741, I think that's pretty much out there by itself and just the transmission seals. I think GM moved the MAF on the 2000s, so may have been a different setup or something.

I'm just outside of Durham, but I'm actually moving down to Charlotte tomorrow for a new job. Was hoping to stay in the Raleigh area, but not much luxury of choice in this economy!

JimD
03-24-11, 04:40 PM
This was gathered from my '04 Service Manual re P0101. If there are no wiring problems or connector mating problems, I would begin to question the accuracy of the coolant temperature sensor and possibly the inlet air temperature sensor. The Service Manual emphasizes wiring and connections time after time. And since you get P0101 with two different MAFs, that leaves your chassis wirng/connectors and PCM.

Deeper diagnosis requires a TECH II and or the ability to read freeze frame data. And the '04 manual does have some voltage and resistance spec's plus a frequency spec of 5 KHz for the MAF (the Service Manual says to connect a "signal generator" to the MAF but common sense tells me that really should say "frequency meter").

Regarding P0741, the '04 Service Manual says nothing about P0101 related to or inhibiting P0741. If you are satisfied there is no crud circulating in the transmission that could cause the CONVERTER CLUTCH CONTROL VALVE to "stick" from time to time, you are probably in the torque converter and seal replacement business.

Ranger
03-25-11, 12:20 AM
I don't think there is any relationship. The 741 is based on slippage % between the trans input and output.



Perfect time to fix that. The P0741 by itself indicates the seals between the trans and torque converter have started to leak and TCC lockup is slipping. Somewhere here in this forum is a thread on that job. If I remember, the seals and the torque converter bearing get replaced. Then you also have to replace the torque converter itself. And while you have the trans open, replace the TCC solenoid ($20) just for insurance against a future failure.
This might be the thread you speak of.
http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/149834-information-p0741-p1860-1998-a.html

billdish82
03-03-13, 02:24 PM
Logically speaking I don't see any relationship between those two codes. Can't explain the FSM though. That's strange.



Could this be possible that a P0101 code is or was tripping the P0741 or am I just off my rocker hoping the 2 are related??? :hide:

I haven't had either code trip since repairing the 2 small vacuum leaks back on 01/17/11. My plan before my HG recently failed was to have the dealer update my PCM software for a TSB that effects the 2000 N* to eliminate nuisance P0101 codes (they loosened the parameters that trip the code) if the codes reappeared. Since the engine will be coming out of my car soon should I try to replace any parts for the P0741 and if so what?

Thanks in advance for any advice or if just want to tell me that I'm a freak'in genius or I've lost my mind thinking these 2 codes are somehow related...


I don't think there is any relationship. The 741 is based on slippage % between the trans input and output.

I am a total newbie here so forgive my boldness in replying, but when I was searching for this p0101 on here I came across this post that might be of interest to those involved in this discussion.



Document ID# 237042
1998 Cadillac DeVille
DTC P0101 Mass Air Flow (MAF) Sensor Performance

Object Number: 244383 Size: SF
Click here for detailed picture of above image.
Circuit Description

This diagnostic test is used to determine if the Mass Air Flow sensor is providing proper readings to the PCM. The MAF sensor is a high frequency device that measures the rate of air flow through the throttle body. The MAF sensor outputs a series of pulses that vary in frequency with air flow. This signal is used by the PCM for fuel control. MAF readings during acceleration will be much higher than those during deceleration or idle. The PCM calculates what MAF reading should be received from the sensor under certain conditions. When the test conditions are met, the PCM will compare its calculated MAF value to the actual value received from the sensor. The calculated MAF reading is done by comparing MAP, RPM and Intake Air Temperature. The allowable difference between calculated MAF and actual MAF varies depending upon flow. If this difference is too great DTC P0101 will set.
Conditions for Running the DTC

* DTCs P0102, P0103, P0106, P0107, P0108, P0121, P0122, P0123, P0560 and P1108 not set.
* Ignition voltage between 11 volts and 16 volts
* DTC P0101 has not previously failed this ignition cycle.
* In closed loop fuel control.
* Canister Purge Duty Cycle is less than or equal to 99.6%.
* EGR rescaled pintle position is less than or equal to 240 counts.
* DTC P0401 not testing EGR.
* Traction control not active.
* TPS is less than or equal to 50 degrees.
* 100 msec delta MAP is less than or equal to 5 kPa.

Conditions for Setting the DTC

The difference between the actual and calculated MAF has been too great.
Action Taken When the DTC Sets

* PCM disables the EVAP control solenoid.
* PCM disables long term fuel trim.
* PCM substitutes calculated MAF value, based on engine speed and throttle position, for actual MAF.
* PCM disables torque management.
* PCM maintains transaxle shift adapts at their current levels.
* PCM disables TCC.

.

Submariner409
03-03-13, 02:39 PM
Welcome aboard !!!! ............. :highfive:

Good find - One more piece to try and fit into the TCC puzzle.

As you'll learn, there is LOT of information in these threads and forums that has been swept under the rug.

billdish82
03-03-13, 04:55 PM
Thanks for the welcome! I just got lucky to put these two together. BTW U rock. Ive been poking around here and you are very active. The forum communities need more people that are passionate and quick to respond to posts like you.

Welcome aboard !!!! ............. :highfive:

Good find - One more piece to try and fit into the TCC puzzle.

As you'll learn, there is LOT of information in these threads and forums that has been swept under the rug.

Submariner409
03-03-13, 05:25 PM
73, retired (3 times), gearhead, past Navy instructor, hobbyist car mechanic, winter explains the time spent in CF. Spring, summer, early fall - different altogether.

CadillacLuke24
03-03-13, 08:25 PM
73, retired (3 times), gearhead, past Navy instructor, hobbyist car mechanic, winter explains the time spent in CF. Spring, summer, early fall - different altogether.

Translation: One COOL dude :D :thumbsup:

Ranger
03-03-13, 10:53 PM
I still do not see any relationship between P0101 and P0741.

Manic Mechanic
03-03-13, 11:56 PM
There's not one. Here's the deal, the P0101 will not set if the P0741 is current. Why? Look closely at how the PCM determines the MAF is faulty:
"The PCM calculates what MAF reading should be received from the sensor under certain conditions. When the test conditions are met, the PCM will compare its calculated MAF value to the actual value received from the sensor. The calculated MAF reading is done by comparing MAP, RPM and Intake Air Temperature. The allowable difference between calculated MAF and actual MAF varies depending upon flow. If this difference is too great DTC P0101 will set."

Without the torque convertor locked to the crank the rpm fluctuations can/will happen so quickly that the MAF readings will be spiky. That is not enough consistency in readings to allow for a condemnation of readings out of specs.
Any time you see conditions for setting a code that lists other codes not previously set it is because if there was a code already set that signified a problem somewhere else that would also cause false readings here. That would lead to more codes based on faulty information upstream somewhere. This is also why you start fixing to lowest number codes first, they are the most fundamental to engine operation.

The only link to these two codes is that if your trans convertor won't lock and your MAF goes bad you won't receive a code because the PCM stopped checking when it couldn't lock the convertor. Otherwise one doesn't care what the other is doing.

Also even though he wants the world to stop using the word "warped" to describe brake rotors with surfaces that are no longer flat, and yet still advocates putting motor oil into engines :D, I will also vouch that Sub is a pretty cool dude. If it wasn't for guys like Sub and Ranger, Basscat etc. (there's a bunch here but they are just the most prolific) I don't think I would have fixed my Caddy, if I did it would have been much harder. You guys are a lot of help.

Vernon

mhamilton
03-04-13, 01:24 PM
The only link to these two codes is that if your trans convertor won't lock and your MAF goes bad you won't receive a code because the PCM stopped checking when it couldn't lock the convertor. Otherwise one doesn't care what the other is doing.

That makes a lot of sense. There's many PCM checks that don't occur until other conditions are met. Off the top of my head, the Evap system leak check won't occur unless the fuel level is between X and Y, the secondary air injector tests don't run if the engine is warm or ambient is above a threshold, etc.

Submariner409
03-05-13, 01:54 PM
No, "he" doesn't want the world to stop using "warped" in reference to brake judder - the people that build the brakes do ..........

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

http://ebcbrakes.com/products/automotive/

Jesda
12-05-13, 07:46 PM
Dealing with this on an 03. What's the short answer? Do I replace/clean the MAF or do I rebuild the trans?