The Oldsmobile Connection

91parkave · Joined: 29 May 2007 Posts: 525

"safe mode" or "limp mode"

..... depending on the problem the computer will go into "Limp Mode" which are factory settings for different sensors. This also changes your shift settings. Limp Mode will allow the vehicle to continue on its way but will run bad enough to make you get it fixed. The trouble codes should be stored. When retrieved may lead you to the main problem. When problem is fixed clear all trouble codes.

thats not open loop in any kind of way brando and andrew k :wink:

andrewk wrote:
You told him that testing with a VOM was not the way to do it, that "it can't predict (I can only assume you mean it cant tell you) when its bad" which is wrong.
heres what i said: using a volt meter cant predict a bad TPS/MAF sensor per say, Theres been times where they will work fine and times when they will stop working, they can do some very starange things....
only speaking from my experience.
andrewk wrote:
The FSM wouldn't tell you to use it if it wasn't going to work. You told him that his MAF goes into safe-mode,
a said a maf gone bad can cause the "limp" mode, dont know where you got that frrom
andrewk wrote: which it does not. I am correcting your piss poor information, nothing more, nothing less. You can stop the diversions anytime.

your whole post was the diversion

Brando · Joined: 06 Jun 2003 Posts: 3069 Location: Michigan, USA

Yea...I scan my ECM all the time to check that it's not in limp mode... :roll:

It's a slang term....the proper term is Open Loop. When something goes wrong (one of the sensors or more isn't working right), the computer opens the circuit to the sensors and relies on it's tables of data to run the engine. Closed loop being when the circuit is "closed" and all sensors are being read by the ECM.

Open Loop: A control system that does not have a feedback loop and thus is not self-correcting.

TOC Admin
Brando

88 Coupe

buickman wrote: ........ only speaking from my experience ........
Yes, we know.

buickman wrote: andrewk wrote: ........ You told him that his MAF goes into safe-mode,
a said a maf gone bad can cause the "limp" mode, dont know where you got that frrom ........
We do.

Here it is, again:

buickman wrote: ........ if so then those are tell tale signs of a bad MAF sensor basicly is "safe mode" where the car runs pig rich. and retards timing at a certain throttle position. ........
It was hard to find, because it is hidden in another of your BS statements.

Norm

andrewk · Joined: 18 May 2005 Posts: 1263 Location: Ames, IA

Brando and Norm have most of this covered but this:

91parkave wrote: using a volt meter cant predict a bad TPS/MAF sensor per say, Theres been times where they will work fine and times when they will stop working, they can do some very starange things....
only speaking from my experience.

You said this in contrary to the recommendation that he use a VOM to test his TPS, seen here-

88 Coupe wrote: Faulty TPS would cause idle, possibly off idle, problems. Not the symptoms you describe.

TPS test, using a VOM, is an easy one. Your FSM should show how it's done.

If the TPS were malfunctioning, the voltage readings would be out of spec, or close to spec. You are wrong to tell him that a VOM will not work.

Funny you should mention your experience-

91parkave wrote: only speaking from my experience.

91parkave wrote: I didnt say it happened to me this is your problem because it happened to me. No no i didnt.

Which is it?

91parkave wrote: your whole post was the diversion

Diversion to the correct information. You can stop being childish anytime now.

myfathersoldsmobile · Joined: 15 Sep 2007 Posts: 41

I was thinking of installing a new oxygen sensor anyway, so that will be step 1 for me. I am definitely interested in testing the coil, too.
But there's something I forgot to mention. :blush: Two years ago, long before the head gasket and valve job this car would lose spark for no apparent reason. It stranded my wife once, I towed it to a shop and it started right up in the parking lot. For awhile this would happen and it seemed to be just a shaky connection at the ignition module. I took off the connection and blew out a decent amount of dust from it. After that there were no other apparent problems. I wonder if that past problem and this new one are connected.
I will pull that plug off again and blow it out when I install an 02 sensor. I'll let you all know what happens. Thanks!

91parkave · Joined: 29 May 2007 Posts: 525

I seriously doubt its ignition related but take the coil pack assy off and bring it into autozone. They can test the ICM (ignition Control Module) free of charge. That way you help eliminate that from a possibility, IIRC it should be 3 11/mm nuts holding it to the plate and a 7mm bolt should be holding the harness to the ICM

Edit: its free by the way and id test both if i were your first check thee ICM as stated above then check your coil packs.

andrewk · Joined: 18 May 2005 Posts: 1263 Location: Ames, IA

As posted before, here is a tech article from Bonneville club that will show you how to test the ignition yourself.

Coil Test

myfathersoldsmobile · Joined: 15 Sep 2007 Posts: 41

Thanks for the additional advice. As I drove it home today , the check engine light came on for the first time. If this stays on can I take the car to Auto Zone so they can pull code from the car? I wonder if this might allow for a clearer diagnosis by code now that the check engine light has come on.

91parkave · Joined: 29 May 2007 Posts: 525

absolutley either way though if it goes off the code might still be stored in the computer so have them scan it anyway.

88 Coupe

myfathersoldsmobile wrote: ........ can I take the car to Auto Zone ........
Not my first choice. If it is your only one, note what is done during the test. Then post the procedure, along with all codes, here.

Do not buy any parts at that time, as the test results will only show where to look, not the actual cause.

Norm

myfathersoldsmobile · Joined: 15 Sep 2007 Posts: 41

Here is the latest update. I took the car to Auto Zone. When they tried to scan it, the display read "link error", so I wasn't able to get it scanned. I bought an O2 sensor,(not from Auto Zone) and installed it this morning. Though it seems to run a little better, the old symptoms still exist. It hesitates during acceleration and especially at 2000 rpm or lower. If I punch the accelerator it will overcome the hesitation, but maybe that's just a side benefit to the resulting downshift and rpm increase. I guess I'll check the coil next, unless you guys think I should try to get code by using a paper clip. I am only vaguely familiar with that procedure and I searched for that information in the forums here. Brando indicated that 16 pin OBD's can't be read by the paper clip method, and I have a 16-pin connector. I assume that I can't read it by using that method. I wonder if Auto Zone used the correct method to scan my car or if my connector is in some way defective.

91parkave · Joined: 29 May 2007 Posts: 525

you have the 16 pin obd 1 connector which wont work with either of the two methods (paper clip,OBD2 scanner) you need a autotron scanner that does the obd 1 equiped cars. I doubt its the coils still but i guess we will have to wait and see.

87Delta · Joined: 15 May 2005 Posts: 686 Location: Mississippi

94-95 cars are OBD 1.5.

myfathersoldsmobile · Joined: 15 Sep 2007 Posts: 41

I just confirmed with Auto zone that thay can't scan either OBD-1 or OBD 1.5, only OBD2. I guess I'll need to look elsewhere for a scan.

91parkave · Joined: 29 May 2007 Posts: 525

Dealership or a some performance shops will have the obd 1.5 scanners. just ask around, a performance shop would be my first stop though.