Last post on Sep 11, 2012 at 3:39 AM
You are in the Cadillac DeVille
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Cadillac DeVille, Lights, Electrical, Sedan
#29 of 191 Re: 97 Deville service engine soon light on [stealerman]
Apr 20, 2006 (7:33 pm)
After holding down on the warmer and off buttons,the computer will open up and start running the various system circuits,it will stop on any trouble code that is currently present for a few seconds and then continue on,until it runs the whole system.
The system will also stop on trouble codes that are history.
Be sure to write down the current number code,so you will be able to look it up,and find which circuit the trouble is in.Once you find the problem and repair it,you will have to clear that code,by either using a code scanner,which you probaly dont have or by disconnecting the positive lead on the battery for five minutes and then reconnecting.If the code comes back again you have not corrected the problem and if it dont come back I would consider your repair a success.You will have to reset certain settings,like the clock and radio settings.To find a list of trouble codes for your caddy,enter in keyword 1997 cadillac Deville trouble codes,ther you will find the code lists.
#30 of 191 Re: 97 Deville service engine soon light on [vic8]
Apr 21, 2006 (2:54 pm)
Thank you so much one more thing if the car runs a complete scan does it end up pcm? on screen if so i have figured it out Thanks in advance for all the help Robert.
#31 of 191 Re: 97 Deville service engine soon light on [stealerman]
Apr 22, 2006 (9:44 am)
Yes,I have the same PCM? on my 1997 Deville after running the system.I do not know what the question mark represents,I'm trying to find out,But I did repair my problem,which was an Oxygen sensor (trouble code P1139)which I did replace. If I was unable to access the on board
computer and find the trouble code,that was causing the problem,I would of been at the mercy of my Cadillac dealer and you know what that would of cost.
#32 of 191 Re: 97 Deville service engine soon light on [vic8]
Apr 22, 2006 (5:49 pm)
Thank you for your time God Bless.
#33 of 191 Service Engine Soon Light is back on again
Apr 11, 2006 (6:13 pm)
About 4 months ago my Service Engine Soon Light came on,on my 1997 Cadillac Deville.I found out how to access the on board computer and found the trouble code,which was causing the light to come on. The trouble code was P1139,which was the oxygen sensor located behind the catalytic converter.I purchased a new sensor and installed it. After the installation,I disconnected the positive lead
to the battery and cleared the trouble code. Now after 4 months of operation and no incidents,the same code has suddenly reappeared.Now what?
#34 of 191 Re: Service Engine Soon Light is back on again [vic8]
by MrShift@Edmunds HOST
Apr 12, 2006 (8:05 am)
YOu were fooled by the code. The code doesn't identify the defective part. No onboard computer can yet do that. It just identifies the circuit with the problem. So you need to start a diagnostic "tree" on that circuit and eliminate each component in the circuit by testing. Your 02 sensor was probably stressed out by some other defective function, so putting in a new one was possibly just providing a fresh victim for the real culprit.
#35 of 191 Re: Service Engine Soon Light is back on again [Mr_Shiftright]
Apr 12, 2006 (1:55 pm)
Thank you for getting back to me.When I originally read the trouble code it pointed to the oxygen sensor,but after it finished running through all the other systems it came to the end and left me with a PCM?.Could this be that, the problem is somewhere in the PCM circuit?
Today I had a friend of mine put his code meter on and came up with the same P1139 code oxygen sensor,his meter did show another code that was not showing up on the cars computer.The code he read said #6 cylinder has miss fired.
Could this possibly be the problem,thats causing the oxygen sensor to go bad?Thanks Again!
#36 of 191 Re: Service Engine Soon Light is back on again [vic8]
by MrShift@Edmunds HOST
Apr 12, 2006 (2:29 pm)
Hmmm....tricky question, like the chicken and egg question...if the 02 sensor is bad, it can't tell the computer how to adjust the fuel mixture, so THAT could cause a misfire....but can a misfire cause a bad 02 sensor....I don't think directly, but a bad misfire could overheat the catalytic converter and THAT could eventually cause the 02 sensor to become contaminated I believe.
So the short answer....I don't know for sure. This is where thorough diagnostics comes in.
#37 of 191 Re: Service Engine Soon Light is back on again [Mr_Shiftright]
Apr 13, 2006 (11:35 am)
Thanks again for your help.I think I'm going to change the plugs,take out the new sensor I installed four months ago clean it up,put it back in, then clear the sensor code and cross my fingers,arms,legs,eyes and what ever else you can cross ha ha! Thanks again Buddy!
#38 of 191 95 DeVille just won't start
Jun 08, 2006 (4:39 pm)
This is a 95 Cadillac DeVille with the 4.9L V8 that was running well and then one morning it would not start. It will turn over strong when the key is turned but it won't fire. Pulled the fuel line just before the fuel regulator and the fuel comes out strong when turning key to start. Checked the fuses that had to do with the ignition and fuel injectors and they check good. I pulled the plastic cover off the distributor and found what looked like the coil. Checked the plug and contacts and there is no voltage to the coil when turning key to start position. I went ahead and made a guess to change out the ignition module inside the distributor housing and that did not fix it. I have checked the codes and the codes I have recorded are as follows:
Could someone give me an idea where to go from here????
Thanks in advance for any ideas.