: Odd Check Engine Light.....



DopeStar 156
08-09-07, 12:14 AM
After driving my Fleetwood around for about two hours doing errands today I noticed the car at highway speeds going up an incline, the Check Engine light would come on for a few seconds then go out. Something like 5-10 seconds and everytime I went up a hill at like 63-65 MPH. Also Cruise was on, what's with the CE light? The performance didnt change or anything......

Help!

danomac
08-09-07, 07:40 PM
Did you check the codes? Even intermittent failures should show up for several start cycles before it's cleared.

jayoldschool
08-09-07, 09:08 PM
The codes will tell you, but that sounds like EGR to me. I remember I used to get that on my old 88 Caprice with the TBI 4.3 V6...

DopeStar 156
08-09-07, 09:13 PM
I don't have a code puller to check the codes and my car lacks a built in one. My EGR should be fine it's only a year old! I just replaced it! Looks like I need the codes pulled, huh?

Cadillac Giovanni
08-09-07, 10:51 PM
I recall there being a way to do it involving jumping two of the pins in the computer harness under the dash. I can't say which ones. This causes the check engine light to flash the codes to you, however.

RocketFast321
08-10-07, 01:40 AM
The top two on the right.

DopeStar 156
08-10-07, 01:57 AM
Someone actually hinted that it might be a "Running Rich" code. I remembered this happening once before right after I had my new carb put on and the settings were all screwed up. I've been suspecting my carb's settings are off. Anyone agree?

Also how do I decipher the CE light blinks?

Night Wolf
08-10-07, 04:23 AM
All GM OBDI cars.....

The Secret Code Puller (SCP) is very hard to come by, and when you do find one, they'll usually go for a hefty price....

Finding one consits of locating a used (or new) paper clip, or other fine metal wire (paper clip is easy tho)

step 1: acquire paper clip

step 2: unfold paper clip so it is in a [somewhat] stright line

step 3: bend paper clip in a U shape, so the ends are 1/3" apart.

Locate the Assembly Line Data Link (ALDL) connecter under the dash, should be near drivers right foot, or in the center, jump pins A and B, they are right next to each other, as RocketFast said, the top two on the right.

Leave the custom SCP installed in the ALDL and perform the Ignition to On Position (IOP) procedure, without starting engine.

Once the SCP is installed in the ALDL and IOP is performed, count the number of Check Engine Light (CEL) Blinks (B) [CELB for short]

The CEL will B code 12, that means the On-Board Diagnostics (OBD) is working, and system is ready. Each code is repeated 3 times, and code 12 is done at the start of the OBD cycle, and once all, if any codes are stored.

Codes work as follows:

Code 12 = 1 Short Blink (SB), Pause (P), two Fast Blinks (FB), then a Slightly Longer P (SLP), followed by the code two more times.

Once code 12 has flashed 3 timesm, there will be a slightly longer P, it will flash any stored codes, 3 times each, going thru the codes starting with the lowest numbers, then going up, until there are no more codes, then the code 12 will flash again.

So code 12 will be this:

*flash* P *flash-flash* SLP *flash* P *flash-flash* SLP *flash* P *flash-flash*

With the CEL performing the *flash* AKA CELB.

If no codes were store, it would repeat 12 over again, but if a code is stored, then you'll get the codes next, each flashed 3 times before the next, or code 12 is flashed again.

If its like my car, the CEL will always be on, for the last 9 years.... Its for the TPS sensor, even tho the TPS sensor has been replaced and adjusted... and I'm sure its for the speed sensor too since the speedo isn't working... I haven't checked since I got it actually.

Hope this helps! :)

DopeStar 156
08-10-07, 01:07 PM
A complicated set of instructions, but I think I got it. I think I'm gonna video record this so I can watch it a few times......

Night Wolf
08-10-07, 02:27 PM
lol... its really not THAT difficult......

casciomichael
08-10-07, 09:04 PM
Arent the 81-92 deville/broughams diagnosed by simultaneously pushing off and warmer buttons on the climate control. Then having the codes displayed on the climate control display. I have a FSM for a 84 cadillac tucked away, I will double check for the instructions.

Mike

DopeStar 156
08-10-07, 09:35 PM
The 307 powered cars won't do it which I don't understand why not. It only requires two digits to display a measly OBD1 code and the ECC display is capable of showing three......

Night Wolf
08-10-07, 09:37 PM
The 307 powered cars won't do it which I don't understand why not. It only requires two digits to display a measly OBD1 code and the ECC display is capable of showing three......

Its a completly different system. The HT4100 with the TBI had a bunch of stuff the 307 dosn't.... its not like they were like... hmmm... check engine light flash or digital readout?

Anyway, its not hard at all to count flashes... really, it takes about 30seconds.....

MadCaddie69
08-11-07, 11:33 AM
Might be your MAP sensor. Mine is doing the same thing.

DopeStar 156
08-11-07, 01:56 PM
I did the paper clip blinking CE light thing and if my understanding of reading the codes is correct (first comes the tens place, then the ones place) then I got 21, 44, and 45. I found a site (http://www.troublecodes.net/cadillac/cadbrom.shtml) and looked under the PCM Codes since mine don't come from the ECC.

According to this site the codes translate as follows:

21: Open throttle position sensor circuit fault
44: Lean O2 signal
45: Rich O2 signal

Lean/Rich O2 signal I understand has something to do with the carb settings but what about the code 21? What does that one mean and what needs to be fixed? Also will fixing the code 21 automatically repair the code 44 and 45? I need help!

jayoldschool
08-11-07, 02:10 PM
I did the paper clip blinking CE light thing and if my understanding of reading the codes is correct (first comes the tens place, then the ones place) then I got 21, 44, and 45. What do these codes mean?

21 (E21) Shorted Throttle Position Sensor Circuit (DFI)
Wide Open Throttle (WOT) Position Sensor Circuit (all others)

44 (E44) O2 Sensor Lean

45 (E45) O2 Sensor Rich

From: http://myweb.accessus.net/~090/81cfb.html

I would start by checking the TPS. This would cause the 44 and 45, I beleive, as well. Get a FSM is you don't have one: it will have all the steps to diagnose and fix stuff like this.

EDIT: just realized you don't have a TPS. Try a new AC Delco (not Bosch or other) O2 sensor. Even if this isn't the problem, it will give much better mileage than the old one.

Here is a FANTASTIC deal for your FSM!!! Don't even check other prices, just go buy it now!

http://cgi.ebay.com/ebaymotors/1989-CADILLAC-BROUGHAM-SHOP-SERVICE-MANUAL-BOOK-89_W0QQcmdZViewItemQQcategoryZ34230QQihZ001QQitemZ 110130164568QQrdZ1QQsspagenameZWD1V

DopeStar 156
08-11-07, 10:11 PM
I did some research on what a TPS does and this is what I got.

Throttle Position Sensor (TPS)
The throttle position sensor responds to the accelerator pedal movement. This sensor is a kind of potentiometer that transforms the throttle position into output voltage, and emits the voltage signal to the ECM. In addition, the sensor detects the opening and closing speed of the throttle valve and feeds the voltage signal to the ECM. The ECM receiving the signal from the throttle position sensor determines idle position of the throttle valve. This sensor controls engine operation such as fuel cut. On the other hand, the "Wide open and closed throttle position switch", which is built into the throttle position sensor unit, is not used for engine control.

Would this thing's failure be the reason why my car sucks going up hills, doesn't downshift at the right time, shifts a little roughly sometimes, and has such crappy take offs? I price checked a TPS at Auto Zone and they quoted me $27 but there's some adjustments I wouldn't know how to make so I might have to turn to a shop for this one.....

Night Wolf
08-12-07, 12:18 AM
The CCC 307 does indeed have a TPS.

No it woudln't have anything to do with shifting... no part of any shifting is controlled by the computer, the only part of the entire transmission that is computer controlled is the torque converter lockup.

What would cause sloppy, or early shifts, or late shifts... GRANTED the trans isn't going out, and the fluid is clean...

#1 vaccum modulator. Cheap and easy to replace, good to replace even if good

#2 Adjusting the TV cable. I think you said the carb was replaced recently? I dunno, but if the TV (throttle valve) cable isn't adjusted right, that will control the shifting, basically make it shift too early, and not downshift.

The TPS is easy to replace, yes it does need to be adjusted, you are looking for a given value, in volts (using a multi memter) to adjust it.

Basically, as on my '93 Coupe, instead of a multi meter, I used the cars on-board diagnostics, becuase it told me the value in volts... the TPS is held on by 2 screws... think of it as a volume control on your stereo, but instead min volume means idle and max volume means wide open throttle... thats how the computer knows how much thorttle is being appiled to the engine.

Well, what needs to be adjusted is that min volume setting. You can loosen (but not remove) the 2 screws, and the TPS will kinda rotate. There is a value in the book for what the TPS *should* be at idle (IIRC, its idle) so you hook up your multi-meter and simply turn the TPS until it is, well, in the middle of the range of values, then tighten the screws up.... thats it.

BTW, TPS is a common failure on these things... and O2 sensors usually go as a car ages anyway.

Night Wolf
08-12-07, 12:37 AM
Alright, here is a little more about the TV cable and stuff....

When Rich was still using his '87 Brougham, it was running like crap... no power at all, and he just had the brand new engine put in.

Well, we spent a few hours looking at it... found a few things...

So after checking everything else.... I thought about timing... maybe its off? So I got a timing gun and we checked the timing... it was right at 20* and we coudln't figure out what the heck was going on.

First up, Olds runs a pretty aggressive timing... 20* BTDC, the distrubutor is a computer advanced.

Well, I forgot what pins ont he ALDL connector you jump, it may even be A&B (it was on the Olds CCC website thing tho) but you jump the pins and it forces the computer to cancel any timing advance.

So we did that, idle died down... and THAT is when you adjust timing... before any mechanical or electronic advance takes place... and... sure enough, the timing was right around 10 or 12*... bascially when the shop put the new engine in, the adjusted timing with the computer already electronically advancing the timing... so we set it to 20* BTDC witht he pins jump.... man, when we shut it down, pulled the pin and started it back up, it sound really good... so we took it for a drive... it ran soo much better, it really did, it sound better too... but it was still shifting wayyy too soon under WOT, like shifitng into 2nd at 20 or 25mph.

So we brought it back, checked out the TV cable, we adjusted it out all the way one way.... just driving thrut he parking lot it would shift into 2nd way too soon, so we adjusted it all the way the other way....

Man, getting out and accelerating on the highway (I lived right next to it) that car took off like it never did before (hold on tho, its still a 307) I mean, it really wanted to spin the tires, it did (but it didn't) but it ran really nice, and shifted around redline, cause the 1-2 shift didn't happen until 40 or 45 mph... and it sound strong too... so we left the TV cable at that.

So for anything with shifting, play with the TV cable, there really isn't any secret thing needed, just play with it and drive it, moving it one way will make it shift sooner, the other will make it shift later, and also control how much throttle input is needed until it downshifts (quick to downshift when you hit the gas or slow)

How does the engine run when you run it wide open? This problem with it loosing power on hills, does it still do that under WOT?

Reason I ask is because all the computer controll stuff only controls the carburator (engine) from idle until about 80% throttle.... when you run the engine wide open, the computer and all the sensors don't do a darn thing and it is just a classic 4bbl carb doing its job.... why I mention that is because if it is still stumbling and loosing power when ran wide open... then it isn't a TPS or O2 sensor thing, and probably a problem with the carb itself.... but... if it runs good wide open, but bad under part throttle, then it is probably a sensor or part of the computer system.

Keep in mind tho, TPS is known to go on these cars, and... most any car when they get older, same as the O2 sensor, I'd replace both of them just to be safe.

BTW, remove your air cleaner, stand on the passenger side of the car, look at the carb, you'll see a hinged metal plate that covers the secondaries (2 larger bores to the rear of the car/carb) That is there, so, if the system is working, it prevents them from opening until the engine is fully warmed up... well, move them with your hand.... see that metal prong thing that hits the lip on the carburator? Notice the secondaries still aren't fully open (vertical) and only about 70% of the way open? Get some pliers and bend that tab out... now open them.... they'll open all the way....

It'll give ya a little more power under WOT... why it was there... no idea.. it is just limiting the amount of air that can enter the carb, which thus limits the fuel entering the engine... in turn limiting the power output.... it'll make a little noticeable difference too.

DopeStar 156
08-12-07, 01:44 AM
All good info, unfortunately I'm not with the car and won't be until Monday but I'm gonna look back on this and make all the proper observations. Let's see if I can provide a little more background on my problem(s).

My shifting issues aren't anything catastrophic, just not right. My car jumps to second gear at 20 MPH at partial throttle and when it shifts to third, there's a reduction in power right after the shift. The shifts just seem to be at the wrong time and if the RPM's are off then the shift doesn't feel right. It's not a slip or a bang but it feels like it wasn't on the mark. At highway speeds the shifting is almost unnoticable and there's no disturbances.

When going uphill if I get the proper momentum and hit the hill at WOT it's fine. The car holds a good 40 MPH all the way up. Partial throttle it's a different story. The car stays in whatever gear it's in and no matter how far I push the pedal nothing seems to change, it creeps around 25 the whole way.

When stopped in Drive at a light or stop sign the car is shaky due to a low idle. This happens 85% of the time I've noticed and when I take off from that stop there's plenty of hesitation unless I hammer the gas. The car only runs crappy when it's not moving (no gas pedal applied) and when it takes off the shifts are off the mark. The car needs the pedal hit once if it's been sitting for longer than an hour and if I have a few unsuccessful starts, it idles poorly in Park and just as bad in Drive if it doesn't stall, which it rarely does. This isn't how I remember the car when I first bought it. I remember having to pump the pedal only if it had been sitting for like 8 hours. Anything earlier than that I just had to flick the key and everything started right up and ran fine. No shifting issues either, they used to be seamless and for the most part unnoticable. We're only talking three years ago......

It's because of this it lead me to believe the carb settings were wrong. However if the TPS is messed up I guess it would throw off the idle from the computer's end causing all kinds of issues. When everything is functioning mechanically as you put it, nothing seems amiss but when the computer is messing around things seem wrong. I have a feeling the TPS is what's throwing everything off because of what it's job is, and that's what appears to not be happening. As for the adjustments, I don't have a scanner nor do I have a multimeter so I don't have any confidence in setting it right myself. I might want professional help on this one since I don't wanna screw it up. If I had the scanner though I'd be more inclined to do it myself.

Night Wolf
08-12-07, 02:41 AM
dude, the shifting sounds TV cable related... maybe its broke? I dunno, but atleast play witht he adjustment.

And replace the vaccum modulator while you are at it, its cheap.

You've got 2 seperate issues going on, the rough engine, and the wierd shifting.

Once the shifting is figured out, floor it from a stop until like 60mph or something.... like I said, if its ok, its probably cmoputer related.

But only going 40mph up a hill at WOT? thats not right... I dunno tho without seeing it...

The Ape Man
08-12-07, 07:06 AM
2004R does not have a vacuum modulator. That's why it has a detent cable.

Night Wolf
08-12-07, 07:18 AM
ahhh...... alrighty... that makes sense :)

I actually don't have much first hand experience with it... For whatever reason I was getting the 200R4 confused woth the 440T4 that my FWD Olds had... heh....

DopeStar 156
08-12-07, 11:36 AM
But only going 40mph up a hill at WOT? thats not right... I dunno tho without seeing it...

Actually what I meant was it holds the speed whatever that may be, 40 was just what I was doing at the moment when I recalled an example.....

You think it's the TV Cable? Well that's a relief, I had a problem with it a couple years ago, apparently it had become disconnected so my shop reconnected it during an oil change. Perhaps it was never adjusted correctly. I'll have to play around with it.....

As for the TPS I'll have to have it looked at, I'm pretty sure the shop I frequent won't even charge me just to check the voltage and make an adjustment. I've been going there for like 4 years......

Night Wolf
08-12-07, 06:49 PM
Actually what I meant was it holds the speed whatever that may be, 40 was just what I was doing at the moment when I recalled an example.....

You think it's the TV Cable? Well that's a relief, I had a problem with it a couple years ago, apparently it had become disconnected so my shop reconnected it during an oil change. Perhaps it was never adjusted correctly. I'll have to play around with it.....

As for the TPS I'll have to have it looked at, I'm pretty sure the shop I frequent won't even charge me just to check the voltage and make an adjustment. I've been going there for like 4 years......

You want to check the voltage and make the adjustment AFTER you put the new one on....

tomc65
09-09-07, 02:03 PM
My 94 deville engine light & security light comes on after about 10miles driving
The code is PO39 my auto not subject to 1995 bulletin for a change in chip .Car runs fine but I would sure like to get rid of warnings on dash.