[Cadillactica12]

Can anyone offer insight on getting rid of these codes?

F13 - In-Car Temperature Sensor Circuit
F15 - Solar Sensor Circuit Failure
E48 - EGR System Problem

I understand cleaning out the EGR Valve/Stack Tubes as I cleaned the throttle body recently, but if you have advice on doing it and what tool to use I'd like to hear that as well.

Thanks in advance. I recently bought this '91 Deville and it has some problems I've already been working on, and a bunch I've yet to squash like the rear struts being gone and some other issues.

 

[dchavezo]

E48- you can attach an old speedometer cable to your drill and use that to clean em out. Works really well. Also replace any broken/worn/damaged/leaky vacuum lines. If the EGR valve or solenoid is leaky or stuck replace those puppies too. Other than the codes what other issues are you having?? Post some pics of you have some, I'd love to see your 91!!

--------

not quite sure about the others but I'll read up on em. Do you have a FSM?

 

[basscatt]

Can anyone offer insight on getting rid of these codes?

F13 - In-Car Temperature Sensor Circuit
F15 - Solar Sensor Circuit Failure
E48 - EGR System Problem

I understand cleaning out the EGR Valve/Stack Tubes as I cleaned the throttle body recently, but if you have advice on doing it and what tool to use I'd like to hear that as well.

Thanks in advance. I recently bought this '91 Deville and it has some problems I've already been working on, and a bunch I've yet to squash like the rear struts being gone and some other issues.

================================
here is EXACTLY what you need -

the FSM - Factory Service Manual -

it will be the BEST $25 you'll ever spend -
http://www.ebay.com/itm/1991-Cadill...023?pt=LH_DefaultDomain_0&hash=item25a33d0c5f

 

[ehall]

Can anyone offer insight on getting rid of these codes?

F13 - In-Car Temperature Sensor Circuit
F15 - Solar Sensor Circuit Failure
E48 - EGR System Problem

Looks like you already found the codes page.

F13 is probably the internal temperature sensor that the climate control module uses to control heat and AC. These cars don't have manual controls but instead you set the target temperature and then the controller takes over from there. I don't know where this sensor is, or it could just be a bad ground or something.

F15 is probably the day/night optical sensor for the automatic headlight module. On my 85 the light sensor is in the dash near the left speaker but I don't know much beyond that.

E48 is a generic code that the system isn't working and could mean anything from solenoid failure to clogged ports on the exhaust to clogged tubes in the intake or anything in between.

Best advice if you want to fix this stuff yourself is buy an FSM. If you don't want to mess with the complicated systems, you will need a good garage, maybe the dealer for some of it. I had to get an electrical specialty shop to do some of the work on mine because modules were no longer available and he had to replace parts like diodes and such.

 

[dchavezo]

Can anyone offer insight on getting rid of these codes? F13 - In-Car Temperature Sensor Circuit F15 - Solar Sensor Circuit Failure E48 - EGR System Problem I understand cleaning out the EGR Valve/Stack Tubes as I cleaned the throttle body recently, but if you have advice on doing it and what tool to use I'd like to hear that as well. Thanks in advance. I recently bought this '91 Deville and it has some problems I've already been working on, and a bunch I've yet to squash like the rear struts being gone and some other issues.

Yeah the solar sensor on my 92 is on the dash near the right side vent. Chances are you might not have to worry too much about this one if you aren't using the twilight sentinel

 

[basscatt]

Looks like you already found the codes page.

F13 is probably the internal temperature sensor that the climate control module uses to control heat and AC. These cars don't have manual controls but instead you set the target temperature and then the controller takes over from there. I don't know where this sensor is, or it could just be a bad ground or something.

F15 is probably the day/night optical sensor for the automatic headlight module. On my 85 the light sensor is in the dash near the left speaker but I don't know much beyond that.

E48 is a generic code that the system isn't working and could mean anything from solenoid failure to clogged ports on the exhaust to clogged tubes in the intake or anything in between.

Best advice if you want to fix this stuff yourself is buy an FSM. If you don't want to mess with the complicated systems, you will need a good garage, maybe the dealer for some of it. I had to get an electrical specialty shop to do some of the work on mine because modules were no longer available and he had to replace parts like diodes and such.

==========================
F15 is probably the day/night optical sensor for the automatic headlight module.
no - has nothing to do with the Twilight Sentinel system -

The Electronic Solar Sensor is part of the Electronic Climate Control System.
It is located on top of the instrument panel speaker grill.
The sensor monitors the sun's solar radiation
by telling the Electronic Climate Control system
what angle and the intensity the sun is at.
The Electronic Climate Control then can automatically
make the necessary temperature adjustments

 

[dchavezo]

You're right. Here it is from the horses mouth

 

[ehall]

Interesting

 

[basscatt]

You're right. Here it is from the horses mouth

=========================
gotta LOVE the FSM -
but it takes all the fun out of guessing -

 

[dchavezo]

========================= gotta LOVE the FSM - but it takes all the fun out of guessing -

not gonna stop me from shooting off my mouth haha

On a side note - one question. What sensor controls the twilight sentinel? I always thought it was the one in mention on that right dash speaker grill

 

[mc_marto]

not gonna stop me from shooting off my mouth haha

On a side note - one question. What sensor controls the twilight sentinel? I always thought it was the one in mention on that right dash speaker grill

It's another sensor located in the left speaker grille on top of the dash. Is your twilight sent. not working?

Mine hasn't worked for some time. It worked for a year and a half after I bought it, then stopped, and few months after that it started working again (mysteriously) for another couple of months. It hasn't worked ever since and it's been awhile. I replaced that sensor with a junkyard one, but nothing changed. There is a dedicated module involved as well, which might be bad, but it is stuck in a mysterious spot behind the dash, so... I haven't tried to fix the twilight any further.

 

[dchavezo]

It's another sensor located in the left speaker grille on top of the dash. Is your twilight sent. not working? Mine hasn't worked for some time. It worked for a year and a half after I bought it, then stopped, and few months after that it started working again (mysteriously) for another couple of months. It hasn't worked ever since and it's been awhile. I replaced that sensor with a junkyard one, but nothing changed. There is a dedicated module involved as well, which might be bad, but it is stuck in a mysterious spot behind the dash, so... I haven't tried to fix the twilight any further.

I actually never use mine. At night it seems to work perfectly but during the day I can never seem to get it to keep my headlights or running lights on. That's probably by design, or my dash cover blocks the sensor. Either way I don't bother with it

 

[mc_marto]

I actually never use mine. At night it seems to work perfectly but during the day I can never seem to get it to keep my headlights or running lights on. That's probably by design, or my dash cover blocks the sensor. Either way I don't bother with it

Yes, that's by design. I believe the Canadian export Devilles were the only ones to have DRL as it's mandatory there. Nowadays most cars have the DRL because more and more countries are requiring you to drive with your headlights on during the day, but I don't think any state in the US mandates such a thing yet.

 

[dchavezo]

Yes, that's by design. I believe the Canadian export Devilles were the only ones to have DRL as it's mandatory there. Nowadays most cars have the DRL because more and more countries are requiring you to drive with your headlights on during the day, but I don't think any state in the US mandates such a thing yet.

sounds about right. I didn't like the idea of not being in control of my lights. I'm a control freak like that ha

 

[Cadillactica12]

E48- you can attach an old speedometer cable to your drill and use that to clean em out. Works really well. Also replace any broken/worn/damaged/leaky vacuum lines. If the EGR valve or solenoid is leaky or stuck replace those puppies too. Other than the codes what other issues are you having?? Post some pics of you have some, I'd love to see your 91!!

--------

not quite sure about the others but I'll read up on em. Do you have a FSM?

Previous owner did some sketchy stuff to it. Some weird toggle/switch under the dash, not sure what it's for, and he ripped the headliner off, and has improperly sized tires on her. Bought the Cadillac with just under 100,000 Miles for $950- But it's been used in NY State through the entirety of it's life so there's some significant rust. Rear air suspension does not work at all, compressor ran often, so I unplugged it. I'd really like to fix this somehow, but leaving it stock. Unfortunately I'm more of a computer guy than a car guy. Cruise control doesn't work, and the inflatable restraint light is on. Only get's about 16 MPG Avg, which I think is pretty low.. Rear and dash speakers were blown, only replaced the dash speakers so far and the head unit keeps causing weird noises intermittently. The trunk button in the glove box doesn't work, no heat (defrost works) or A/c and service A/C lights comes on also. This is most of it's issues, and I've done a lot to it already. The exhaust pipe hangs low, I had to rip off the heat shield, and it's pretty loud.

Replaced and repaired so far:

Serpentine Belt
Idler & Tensioner Pulley
Syn Oil Change
Wheel Cylinder
Leak coming from rear windshield, flooding interior with water


In process of replacing:

Spark plug wires
Spark Plugs
Fuel Filter

Any advice any of you guys can offer would be greatly appreciated. The semester is about to end so I should have more free time to work on it.

 

[Cadillactica12]

Especially advice, opinions and suggestions towards repairing the rear air suspension or maybe converting to gas or something.

 

[dchavezo]

Especially advice, opinions and suggestions towards repairing the rear air suspension or maybe converting to gas or something.

if the rear shocks are leaking they'll need to be replaced. A lot of people here like the monroes. Monroe makes a cheap manual full kit that hooks up so you don't need the compressor to adjust for you.

Glove box might be a fuse issue. I'll look into it and hopefully someone can answer with a fuse number to check. I wouldn't worry about the headliner or stereo too much till the engine and suspension are all refreshed

----------

In the words of basscat:

Hold off and warmer on the climate control and write down all the codes that appear. Post them and definitions here and we can help.

----------

Ac light is probably an f47 or something related to low freon. That one is pretty common. If you press auto on the climate control does it switch to Econ relatively rapidly??

----------

(Replace the cap and rotor too and your ignition system should be all set)

 

[davester]

sounds about right. I didn't like the idea of not being in control of my lights. I'm a control freak like that ha

You'd hate my '04 Sierra 3500. It's light switch has three positions "off", parking and headlights. Except:

-the 'off' position is the same as parking, and the switch is spring-loaded, so moving it to off and releasing the knob, it automatically returns to parking (and holding it there doesn't actually turn the lights off)
-parking automatically switches between DRL and headlights being on, depending on how dark it is
-headlights, the only mode that actually does what it says, puts the all the lights on

Course, for me, it's fine, the system seems to be in the right mode whenever I'm driving.

 

[Cadillactica12]

Now I'm having issues shutting the vehicle off, it's become extremely hard turn turn the key to the off position now, and progressively got worse through the day until I finally made it home.

 

[cadillac_al]

Spray some WD40 in there and hope for the best. If that doesn't help you may have to change the switch or at least take it apart.