: Real unhappy with (my new) used caddy - Can't ID the DTC's



ggevaart
11-28-03, 09:54 PM
Hello and Help:

Just bought a 96 DeVille with 105k miles today. Always loved the styling of the mid 90's caddy and fell in love with it on the lot. Should have been more cautious about signing on the dotted line on this one. Emotions got the best of me. Anyway-
Drove it home from out of state. Ran ok for the first 100 miles (not with the power a Northstar V8 I thought should have - I was thinking tune-up perhaps?). Stopped to gas up (premium), started again and the thing could barely get out of its own way on the highway. Anything more than 1/8 throttle and she bogged down and sputtered like the 76 Mustang II I had with the choke stuck full closed (easy to fix). Shifting to 3rd helped gain a little more throttle on the highway. Had to shift from 1st on up from a stop to get 'er moving.

Too far and late in the day to turn around so I limped it home ( another 75 miles). Went right on the internet to find out what needs to be fixed. Search led me here and eleventy-million other places.

Couldn't ID the current DTC's here or on the AWH site. So here they are. I hope somebody can help.


Current DTC's (so far) are:

PC1133
PC1660

They don't show up in either list of OBD-1 or OBD-2 codes.

I have a large list of history codes in the same 2 - letter, 4-digit format I would also like to know more about.

the Sandman
11-28-03, 10:10 PM
DTC P1133: Heated O2 Sensor Insufficient Switching Bank 1 Sensor 1
DTC P1660: Cooling Fan Control Circuits

Sounds like you might need one or two new O2 sensors. And was the car running hot?

BTW - Welcome to the CadillacForums! :welcome: Thanks for registering.

onecad
11-29-03, 09:14 AM
Have now worries!
The guys here are great, and have lots of experience. Your problem is not likely to be anything serious, in these cars, like many other cars, the smallest thing can make it seem like the engine needs major repairs when it doesn't. These cars rely on many sensors, and have the best onboard diagnostic to help you solve problems yourself.

I just recently bought a 1994 eldorado, the car spat and sputtered. It even seemed to me like the transmission was acting up because of the way the car accelerated and jumped intermittently.
The answer....was new spark plugs. Runs like almost new now, and it has 223,000 km's on it.

Just for the hell of it, I know your problem is different from mine, but check your plug wires, these things almost never get changed cause many people think that because the casing looks ok, that they are fine.
Plus, if yours have never been changed, they are way passed due.

As mentioned above one of the codes was an O2 sensor, if these sensors are not working properly your car will not run properly. They play an important role in the air fuel mixture, and quite often the hotter the motor gets the worse it will run.

Welcome to the forum.

I

ggevaart
11-29-03, 10:27 AM
Thanks so far for the help guys.

This forum is great and the members go out of their way to help a guy out. Hope once my knowledge increases, I'll be able to return the favor.

I'll start with the plugs, wires and the O2 sensor and see if this helps.

Regarding the motor running hot - I didn't notice. No mil was displayed, the fan is running. Is there some other way of knowing?. Also, is the 02 sensor avail. aftermarket? If I go to AutoZone and ask for the "Bank 1 Sensor 1 heated O2 sensor" will they throw the part to me or give me that head-cocked, vacuous-eyed look, followed by raucous laughter as I exit the store empty handed?

elwesso
11-29-03, 10:43 AM
You have 2 things that are easy to fix but make it seem like the engine is gonna die!

First, if the o2 sensors are shot (like cant detect anything) it goes on a very conservative AF mixture... Youll have bad gas mileage and even worse performance.... OBDI was much less conservative, but with OBDII the o2 sensors are much more complex, and many more things are detected with the oxygen sensors (like misfires, injector failures to name a few).....

You have 3 (correct me if im wrong) and youll want to replace them all at the same time!! Because when one fails inevitably the others arent gonna be far behind....

Are both of the fans coming on?? I know there is a way to check the temp via OBD, but im not sure how..... Do a search here.... The car should be running in the 210-250 range (hotter than most).... Anything much higher than that and the engines computer begins to retard the timing even more...... When the engine runs hot (above a certain temp), the engine retards the timing to make the engine run less hot.... And for the most part, it works but its really annoying.... For that youll want to check the Tstat, and if thats ok (IE replaced) then you radiator may be shot.....

Welcome to the forums, thanks for signing up :wave:

DaveSmed
11-29-03, 01:22 PM
Part of the fan control circut involves the A/C. Turn your A/C on and see if the fans come on. This is to help pull more air across the condensor. If they come on, the fans, fuses, and relays are OK.

mcowden
12-01-03, 01:31 PM
You have 3 (correct me if im wrong) and youll want to replace them all at the same time!! Because when one fails inevitably the others arent gonna be far behind....
Actually, there are 4 O2 sensors. Two in the engine compartment area in the manifolds on either side of the engine and two under the car on either side of the catalytic converter.

The one that usually goes bad first is the one before the converter. I'm not sure how to translate "Bank 1 Sensor 1." Anyone know which one that is? Whatever that is, I would replace that one first and see what you get. At about $65-$80 a pop, I prefer to save the cash and only replace what's necessary at the moment.

At AutoZone, tell them you need a rear O2 sensor for a '96 Deville and they'll give you a Bosch sensor with the right wiring harness. The two sensors under the hood are called "front" sensors at AutoZone and the two under the car are called "rear" sensors. The difference is that the front ones are unheated and the rear ones are heated. The wiring harness is different as well. Don't get the "generic" sensors if you can avoid it because you have to splice the wiring harness together and that's not usually a good idea with O2 sensors.

ggevaart
12-01-03, 10:21 PM
The one that usually goes bad first is the one before the converter. I'm not sure how to translate "Bank 1 Sensor 1." Anyone know which one that is? Whatever that is, I would replace that one first and see what you get. At about $65-$80 a pop, I prefer to save the cash and only replace what's necessary at the moment.


Searched and found that the bank 1 sensor 1 is on the rear bank. So I guess the sensor I need is the one at the converter from the rear bank. Strange, but I didn't find out anything described as "bank 2 sensor1" intuitively being able to regard this as the front bank then. But I'll start here and keep spanking O2 sensors into it unitil she decides to behave.

Now onto codes again. I have PCXXXX codes ACxxxx, TCxxxx PZxxxx and IRxxxx codes displayed (current and history) when running the self diagnostic. Any more help for a site which fully lists these codes would help.

Also, ran across a site when originally doing my research that talked about how to take a daignostic snapshot but ultimatley lost track of that page in an all- night Red Bull-induced, double-click-mouse-finger-calcifying search fiesta.
Anybody?

mcowden
12-02-03, 11:20 AM
Any more help for a site which fully lists these codes would help.
For quick reference, I use this site to look up codes:

http://209.145.176.7/~090/awh/dtcobd2.html

There are lots of others I think if you just search for the code in Google with something like "PC1520 diagnostic code" or similar. It seems to me that Cadillac codes are strikingly similar to Corvette codes. Hmm. Puzzling. Great. If you're in a spending mood (and who's not?!) consider a $25 annual subscription to Alldata DIY (www.alldatadiy.com (http://www.alldatadiy.com)). It's a service run by AutoZone I think and they seem to have very good code references and even diagnostic action charts for the codes so you know right where to start. I've had very good luck with the site.

Oh yeah, and also about those code thingees, consider clearing them all out and starting over from scratch with what's a CURRENT code and what's HISTORY.

ggevaart
12-02-03, 11:53 PM
[QUOTE]For quick reference, I use this site to look up codes:

http://209.145.176.7/~090/awh/dtcobd2.html


Yeah, I've been to this site numerous times. Very helpfull, but it doesn't reveal the complete mystery of the codes. Many codes are not listed and many codes are duplicated under different prefexes.

If there is anyone out there who can lead us to the land of diagnotsic code comprehension - show yourself now!! (or at least give me an interesting URL link where I can lose myself in for another few precious hours)

If anybody on the forum already has this wisdom , please hook us up. If not I'll spend the clams to get into the ALLDATA DIY site and post any info they are willing to share with me regarding the code cunundrum.

Again, this forum is great! Thanks for all the input.

ggevaart
12-03-03, 12:16 AM
Part of the fan control circut involves the A/C. Turn your A/C on and see if the fans come on. This is to help pull more air across the condensor. If they come on, the fans, fuses, and relays are OK.


Both fans turn on (even at 28deg F) so I'll have to look elsewhere for the fix for the 1660 code. Worried about other things right now rather than the "must use additive- forget the additive" cooling problem debate, among the host of other cooling system potential problems on this forum that I may have to research.

Thanks for the input.

elwesso
12-03-03, 04:18 PM
If you post the meaning of the code, sometimes we can interprit them....

However, a FACTORY SERVICE MANUAL will tell you what they really mean and how to fix them..... www.helminc.com

GET ONE!!!!! Unless you take the car to the dealer for everything, GET THIS!!!