Cadillac Owners Forum banner

1 - 20 of 21 Posts

·
Registered
2003 Cadillac CTS 3.2L V6
Joined
·
275 Posts
Discussion Starter #1
I have 2003 3.2L CTS. I keep getting the following codes:

C1278 - TCS Temporarily Inhibited by PCM (what does PCM mean?)
P0121 - TP (Throttle Position?) Sensor Circuit Insufficient Activity
P2135 - Throttle Position (TP) Sensor 1-2 Correlation
P2176 - Minimum Throttle Position Not Learned
P0700 - Transmission Control System Malfunction (this stays on no matter how many times i clear out the codes)

When driving, the car shifts really rough. When at a light or in park, the idle is moving up and down, at times (not too often) reaching almost 3000 RPM. It usually revs itself between 600 and 1200 RPM. Then I get a message on the radio screen that reads "Service Idle Control." Also while driving, It will randomly stop working. I get an "Engine Power Reduced" message and the car barely stays on.

At times, like this morning, it works fine. I erase the engine codes (P0700 is always on) and it runs smoothly and idles well. Then, the check engine light starts flashing and the process starts over again. I'll even get a "Service Engine Soon" message.

Any suggestions? Please help!!! I do not want to take to the dealership because they will charge too much and not even fix the problem.

P L E A S E H E L P! ! !

I've tried replacing the Throttle Body (sensor was attached to the throttle body) and nothing really changed. It does the same thing.
 

·
Registered
05 CTS
Joined
·
434 Posts
I dont' 'REALLY' know..but that almost sounds like the Torque Converter.......Mine kinda sorta did the same kinda thing. Really just the hard hard shifting, and it acted as if it didnt know when to shift...

Honestly...about a $1200 job I think........but I'm Caddy Certified..thank god.......
 

·
Registered
2003 Cadillac CTS 3.2L V6
Joined
·
275 Posts
Discussion Starter #3
would the torque converter cause the idle to get out of control? The car shifts smoothly when the it is idling well.
 

·
Registered
Cadillac
Joined
·
1 Posts
My son also owns a 2003 CTS, 80,000 miles

We've been fighting rough idling, starting, and "Power Reduced" messages.

Had the following trouble codes.
P0700

P2101
P2119
P0121
P2176
P0507

The vacuum line (hose) under the throttle body was disconnected. Plugged it back and fixed all of the codes except the P0700. The same happens here, no matter how many times I clear the codes, the P0700 comes back on. So now, for lack of experience, I'm disconnecting the negative battery cable in hopes it will reset the P0700 code.

Plan B, take it back to the mechanic (non-dealer) had a transmission installed at 71,000. The yoke broke inside the tranny and took out the whole thing. The mechanic installed a factory rebuilt with a 3yr/100,000 mile warranty. Things I learned, this tranny is made by BMW.
 

·
Registered
2003 Cadillac CTS 3.2L V6
Joined
·
275 Posts
Discussion Starter #5
"Re: 2003 CTS 3.2L "Service Idle Control" "Reduced Engine Power"

--------------------------------------------------------------------------------
My son also owns a 2003 CTS, 80,000 miles

We've been fighting rough idling, starting, and "Power Reduced" messages.

Had the following trouble codes.
P0700

P2101
P2119
P0121
P2176
P0507

The vacuum line (hose) under the throttle body was disconnected. Plugged it back and fixed all of the codes except the P0700. The same happens here, no matter how many times I clear the codes, the P0700 comes back on. So now, for lack of experience, I'm disconnecting the negative battery cable in hopes it will reset the P0700 code.

Plan B, take it back to the mechanic (non-dealer) had a transmission installed at 71,000. The yoke broke inside the tranny and took out the whole thing. The mechanic installed a factory rebuilt with a 3yr/100,000 mile warranty. Things I learned, this tranny is made by BMW
."

Let me know how it goes. Mine is still shifting rough and working fine at times. Its driving me nuts.
 

·
Registered
2003 CTS
Joined
·
5 Posts
Someone who feels my pain. I've had similar problems where the car will rough downshift sometimes and it will give me the "reduced engine power" message and then it will only go about 3 mph. I get the P0700 code which doesn't go away. I also get a couple codes about the throttle position sensor. I was thinking of replacing the throttle position sensor but wasn't sure if that would do it. From what I've researched, faulty wiring could also be the problem but I can't seem to find a throttle body wiring harness online. Anyone have any suggestions on what could be the problem or where I could get the parts?

For the first poster, I hear that idling problems like you described are caused by the PCM getting a reading from the throttle position sensor that is wrong or is inconsistant with the cars rate of speed. The PCM is just trying to adjust to the right level of fuel to deliver and cannot. Not that this is an answer, just passing on what I read somewhere.
 

·
Registered
2003 CTS "Ebony Maria" 2005 Cadillac STS "Grace"
Joined
·
6,414 Posts
joshuaaap...have you ever cleaned your throttle body? and changing the throttle body sensor wont hurt, but the only thing is if it doesnt fix it then you could look at it as wasted money...but i would personally start with the easy stuff, then go a little more in depth every time that it doesnt fix the problem
 

·
Registered
Joined
·
37,297 Posts
I doubt it is the torque converter. I am on my third TC, and I have had none of those symptoms.

Mass airflow sensor maybe? I had one go bad on my Maxima, and I had all kinds of misfiring, reduced power, crazy idle etc. And it was all intermittent.
 

·
Registered
2004 3.6 auto
Joined
·
140 Posts
I didn't notice your odometer reading or if you have a oiled air filter, but I suggest you go to autopart.com and get a new MAF. Got one from them for my 2004 3.6 and it fixed my problem. Car would die out and wouldn't even run after several starting attempts. Best $50 I ever spent.
 

·
Registered
2004 3.6 auto
Joined
·
140 Posts
I forgot to add that after the re-man maf was installed, I still had a high (but stable) idle. To cure that high idle I did:

1. With COLD engine, turn key to ON position for over a minute, but do not start engine
2. Turn key off for 10 seconds
3. Turn key to ON position for 10 seconds, but do not run engine
4. Turn key off.
5. Start your engine


Here's the 2003 maf
http://autopart.com/partsout/2003/CADILLAC_CTS/5128.htm
 

·
Registered
2003 CTS
Joined
·
5 Posts
joshuaaap...have you ever cleaned your throttle body? and changing the throttle body sensor wont hurt, but the only thing is if it doesnt fix it then you could look at it as wasted money...but i would personally start with the easy stuff, then go a little more in depth every time that it doesnt fix the problem
I looked at the inside of the throttle body by taking off the two large air intake hoses and it looked pretty clean. I also looked at the wiring connection at the throttle body and everything looked fine. Do I need to take the throttle body off and clean it out anyway? I'm leaning toward replacing the wiring harness to the throttle body but I don't know if I should or where I can get the harness at a reasonably price.
 

·
Registered
2003 CTS "Ebony Maria" 2005 Cadillac STS "Grace"
Joined
·
6,414 Posts
i would take it apart and clean it personally...along with the electrical connections with electrical cleaner
 

·
Registered
2003 CTS
Joined
·
4 Posts
Okay, so I am just a girl and don't know much about cars but here is what happened to me.
I was getting that exact message and it was driving me nuts and I had made two trips to the dealership paying over $400 in service charges. They never found or solved the problem but of course they weren't lettin me out without a charge so they found something else that supposedly needed fixing. My husband started nosing around in my glove compartment and figured out that something I had in the glove box door was intermittently pressing on the traction? button in the glove box. He removed the offending object and I haven't had any problems since and that has been over 2 months ago. Seems like a silly solution but check it out. My husband claims he is from another planet and that is how he found the problem. Hope this might help someone.
 

·
Registered
2007 CTS White Diamond - 1997 Deville Silver Mist
Joined
·
289 Posts
I have 2003 3.2L CTS. I keep getting the following codes:

C1278 - TCS Temporarily Inhibited by PCM (what does PCM mean?)
P0121 - TP (Throttle Position?) Sensor Circuit Insufficient Activity
P2135 - Throttle Position (TP) Sensor 1-2 Correlation
P2176 - Minimum Throttle Position Not Learned
P0700 - Transmission Control System Malfunction (this stays on no matter how many times i clear out the codes)
PCM = Powertrain Control Module - aka the Electronic or Engine Control Module. This is the main engine computer - the brains of your car that interacts with and controls all other systems in your car. The PCM probably inhibited the Traction Control due to the problem with the Idle Control System.

Did you change the Throttle Position Sensor? After you do this, I believe there's an adjustment and an idle relearn procedure, so just changing the sensor will not fix the problem.

The rough shifting is due to the P0700 code. Your transmission is electronically controlled and if there's a problem with one of the transmission systems, the PCM commands an overide mode. It does this so that the transmission still operates. However, it's no longer electronically controlled, so you will get the rough shifting that you're describing. It could be the Transmission Control Module. It could also be one of the Shift Soleniods - although a seperate code will usually be set to identify which solenoid is malfunctioning. This is a common problem that just requires replacement of the applicable solenoid. There are several that control shifting between 1-5 and one that controls Torque Converter Clutch activity. Depending on which solenoid it is, it can either be a messy, but not too expensive job. If it's the TCC Solenoid, that's a bit more involved as the transmission has to be dropped to change that solenoid.
 

·
Registered
Joined
·
37,297 Posts
Did you change the Throttle Position Sensor? After you do this, I believe there's an adjustment and an idle relearn procedure, so just changing the sensor will not fix the problem.
That consists of turning the key to run (without starting the engine) and leaving it there for about 10 minutes. Then you turn the ignition off, remove the key, and then it should be good to go.
 

·
Registered
Cadillac
Joined
·
32 Posts
In my experience with other GM cars and bad throttle position sensors, this puts the PCM into some sort of "limp in" mode where the transmission shifts at set points (speed dependent, not throttle position dependent), and rather roughly at that. This is because the computer has no idea what the throttle position is, and makes sure there's no transmission slip during the shifts (which would be bad if it was shifting during a wide-open throttle).

It is extremely doubtful that both the TPS *and* the transmission controller went bad simultaneously. It's much more likely that the bad TPS is causing the rough shifting, and this isn't necessarily an indication of a transmission problem.
 

·
Registered
None
Joined
·
1 Posts
I got the same exact problem with my 03 CTS. I took it to the dealer they kept charging me but couldn't fix it..so now my own mechanic just told me what is the problem..I'll have to change the whole complete throttle body - not only the sensor the whole throttle body -and after I get it changed then go to the dealer and get the system reprogrammed because the computer is losing memory. thanks
________________________________________________________________

Good afternoon - Your CF account is activated. please use the profile and Settings tabs to update your profile to reflect proper birthday, approximate location, car owned and time zone - or do you really live in London - GMT ?
 

·
Registered
Cadillac
Joined
·
93 Posts
you might want to check the hose in the pic i attached. i was getting the P0700 and P2119. car would stall, say reduce
engine power and shift hard. i was about to change my ECM and PCM based on everything i read. I found this hose disconnected. good thing i found it and connected it back. after i connected the hose back and cleared all codes by disconnecting battery. i never had any problems since

BTW its the hose without the clamp

20140513_094411_resized_1.jpg
 

·
Registered
Joined
·
6 Posts
I was getting 'reduced engine power' and 'service idle control'. My cts would stall out randomly and did it 8 times in 3 days. I cleaned the throttle body with 'throttle body cleaner' and a small brush from autozone. Next I did a pull test on the electrical wire connections to see if any were loose, they were all good. Then I cleaned the connection with 'electrical cleaner' from autozone. The problem went away and hasn't come back.

In my opinion these should be the first steps taken, as the cost of cleaners is under $10 and your investing 30 minutes. If you take it to a shop they will want to replace something that probably wont fix the problem.
 
1 - 20 of 21 Posts
Top