Sporadic SES light and exotic codes - friend's 2004 DTS
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 1 of 13 1 2 3 4 5 6 7 8 9 10 11 ... LastLast
Results 1 to 15 of 185
Cadillac DeVille 1985 to 2005 including:
1985-1992 Fleetwood, 1993 Sixty Special, All FWD Forum Discussion, Sporadic SES light and exotic codes - friend's 2004 DTS in Past Cadillac Vehicle Discussion; ...
  1. #1
    c_d
    c_d is offline Cadillac Owners Fanatic
    Automobile(s): 06 Beetle 2.5L Manual, 08 Audi A3 TDI, 04 DeVille DTS
    Join Date
    Feb 2012
    Location
    SAT, BER
    Posts
    152

    Question Sporadic SES light and exotic codes - friend's 2004 DTS

    Here I was thinking my Cadillac troubles are over but ... A friend owns a '04 Deville DTS and was complaining to me about the SES light coming on and off randomly. He asked me to have a look since I went through so much trouble with my old Seville. During a test drive I didn't notice anything strange but a rough idle with slightly elevated rpm that totally goes away the warmer the engine got. The Deville also has abyssal gas mileage of below 13 MPG. After a couple of miles the SES light indeed came on and stayed on until we parked the car. 10 minutes later we got back in the car and drove the same route back with the light not coming on at any point in time.

    Strangely, it is not throwing any code that can be read out with the internal code reader but two codes concerning the front seat adjustment motor. One remains of my old Seville was an external code reader that threw out the following:

    Trouble Code: P0174
    ABSLT TPS(%): 14.5
    ENG SPEED(RPM): 2027
    CALC LOAD(%): 50.2
    MAF(gr/S): 29.45
    MAP(KPa): 71.0
    COOLANT(°C): 94
    IAT(°C): 27
    IGN ADV(°): 39.0
    SECOND AIR: ATMOS
    ST FTRM1(%): 8.6
    ST FTRM2(%): 0.0
    LT FTRM1(%): 21.1
    LT FTRM2(%): 24.2
    VEH SPEED(KPH): 78
    FUEL SYS 1: CLSD
    FUEL SYS 2: CLSD

    After some quick research through this board, it could be a vacuum issue. We did a quick check of all apparent vacuum lines and the only one showing clear signs of degradation is the one circled yellow in the picture below. The rubber hose part is cracked by an inch (on the bottom) and the hole connection is very shaky and loose.

    photo.JPG

    Unfortunately, I have no idea what that particular part is or what it's supposed to do - and therefore does not know whether this could be a/the cause for the SES light. I also read here on the boards that I should just get a can with some carb cleaner or so, carefully spray the vacuum lines, and listen for rpm changes to isolate any vacuum leaks. I'd like t do that but was unable to find a picture or diagram clearly marking all candidate spots. Is such a treasure hidden deeply somewhere?

    EDIT: I didn't notice this at first with the code reader: P0174 is marked as "pending" while P0171 was "confirmed". Don't know how that translates into the H/C marks with the in-dash reader.

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    Submariner409's Avatar
    Submariner409 is offline If it won't run, chrome it
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    74
    Posts
    44,513

    Re: [?] P0174 on a 04 Deville

    That's a 2004 ignition system - The piping connector indicated is the "clean air" supply for the PCV system - that particular connection will not cause lean mixture codes - only the vacuum side of the system - and that comes out of the right (rear) cam cover and snake around to a nipple at the tunnel in the front (passenger0 end of the intake manifold.

    P 0171/0174 lean mixture codes are caused by vacuum leaks. Get a mechanic's stethoscope and start searching. Look for plenum leaks. Google "cadillac forums northstar manifold plenum" or something close. It's the rubber/steel connector between the throttlebody and intake manifold. Many pictures/diagrams in my albums. The Community tab ^^^, albums, the red Seville.

    His car has its own built-in code system (I think). Use the sticky ^^^ post "How to pull codes" section for the car, year, model. Use the link with "obd2" in the address to get to the Master Index of code definitions. Be sure to post whether each code is Current or History - it makes a difference.

    Gas mileage - check the Fuel Pressure Regulator nipple and vacuum line for the presence of raw fuel. ANY fuel there is cause for replacement.

    (Your 1999 is a VERY different engine from his 2004 ....................)

  4. #3
    c_d
    c_d is offline Cadillac Owners Fanatic
    Automobile(s): 06 Beetle 2.5L Manual, 08 Audi A3 TDI, 04 DeVille DTS
    Join Date
    Feb 2012
    Location
    SAT, BER
    Posts
    152

    Re: [?] P0174 on a 04 Deville

    Quote Originally Posted by Submariner409 View Post
    That's a 2004 ignition system - The piping connector indicated is the "clean air" supply for the PCV system - that particular connection will not cause lean mixture codes - only the vacuum side of the system - and that comes out of the right (rear) cam cover and snake around to a nipple at the tunnel in the front (passenger0 end of the intake manifold.
    Thank you so much - one more question if I may: is it normal that the connector is slightly greasy/oily? I observed some brown substance on both, the hose and the metal connector.

    Quote Originally Posted by Submariner409 View Post
    P 0171/0174 lean mixture codes are caused by vacuum leaks. Get a mechanic's stethoscope and start searching. Look for plenum leaks. Google "cadillac forums northstar manifold plenum" or something close. It's the rubber/steel connector between the throttlebody and intake manifold. Many pictures/diagrams in my albums. The Community tab ^^^, albums, the red Seville.
    Will do - lots of very helpful pictures. Do I have to use a stethoscope or can I try the carb cleaner can spray trick? I seem to remember that the success of a stethoscope is closely tied to one having a rather quite garage and good ears - I lack both.

    Quote Originally Posted by Submariner409 View Post
    His car has its own built-in code system (I think). Use the sticky ^^^ post "How to pull codes" section for the car, year, model. Use the link with "obd2" in the address to get to the Master Index of code definitions. Be sure to post whether each code is Current or History - it makes a difference.
    Sir, no offence intended but ... I really don't understand why in every answer on this boards refers to this link. We (I) may be amateurs in car mechanics but that doesn't mean that we did not already follow that procedure to the letter. I once had the same issue in my Seville, the SES light came on with no code being fired/displayed. That was exactly the reason why I bought the external code reader.

    The on-board built-in code reader is merely showing a memory seat system code as written above. The P0171/0174 code is only retrievable with an external OBD-II reader. The way I am catching those codes since my first time on this boards is: activate all code display, capture a video with my smart phone, and assess the information at my desk by playing the video. That way no potential code gets lost. Anyway, I called him up to capture a video as well, here's the result:

    MSM B1860 H - driver lumbar vert sensor circuit malfunction
    MSM B1850 H - driver lumbar horiz sensor circuit malfunction
    PCM P1585 C - cruise control inhibit output circuit - This one is new and wasn't there yesterday.

    Quote Originally Posted by Submariner409 View Post
    Gas mileage - check the Fuel Pressure Regulator nipple and vacuum line for the presence of raw fuel. ANY fuel there is cause for replacement.
    I assume the FPR is the little silver silver distributor thing that says made in germany?

  5. #4
    basscatt's Avatar
    basscatt is offline Cadillac Owners Master
    Automobile(s): 89 Coupe DeVille, 95 Sedan DeVille, 03 SLS, two 02 DHS's
    Join Date
    Feb 2004
    Location
    Minnesota
    Age
    63
    Posts
    9,824

    Re: [?] P0174 on a 04 Deville

    Quote Originally Posted by c_d View Post
    Thank you so much - one more question if I may: is it normal that the connector is slightly greasy/oily? I observed some brown substance on both, the hose and the metal connector.



    Will do - lots of very helpful pictures. Do I have to use a stethoscope or can I try the carb cleaner can spray trick? I seem to remember that the success of a stethoscope is closely tied to one having a rather quite garage and good ears - I lack both.



    Sir, no offence intended but ... I really don't understand why in every answer on this boards refers to this link. We (I) may be amateurs in car mechanics but that doesn't mean that we did not already follow that procedure to the letter. I once had the same issue in my Seville, the SES light came on with no code being fired/displayed. That was exactly the reason why I bought the external code reader.

    The on-board built-in code reader is merely showing a memory seat system code as written above. The P0171/0174 code is only retrievable with an external OBD-II reader. The way I am catching those codes since my first time on this boards is: activate all code display, capture a video with my smart phone, and assess the information at my desk by playing the video. That way no potential code gets lost. Anyway, I called him up to capture a video as well, here's the result:

    MSM B1860 H - driver lumbar vert sensor circuit malfunction
    MSM B1850 H - driver lumbar horiz sensor circuit malfunction
    PCM P1585 C - cruise control inhibit output circuit - This one is new and wasn't there yesterday.



    I assume the FPR is the little silver silver distributor thing that says made in germany?
    -----------------------
    Sir, no offence intended but ...
    I really don't understand why
    in every answer on this boards refers to this link.


    the reason is simple -
    if there is a code stored -
    the built-in - on-board code reader WILL display it -

    so there is no reason to use an external reader - AND
    some cheap external readers won't display ALL stored codes -

    there is ONE exception - the generic P0300 - misfire code -
    the on-board code reader will NOT display which cylinder is misfiring -
    where as an external code reader will display P0301 for cylinder #1 -
    P0302 for cylinder #2 - etc -

    that is the ONLY code I can think of -
    where the external reader is superior to the on-board reader -

    I once had the same issue in my Seville,
    the SES light came on with no code being fired/displayed.


    IF the SES light came on - a code was set -
    and if a code is set - the on-board code reader WILL display it -

    you might not have selected "ALL CODES" -
    or you might have missed it - they do flash by fairly quickly -
    but I have never heard of a stored code not being displayed -

  6. #5
    c_d
    c_d is offline Cadillac Owners Fanatic
    Automobile(s): 06 Beetle 2.5L Manual, 08 Audi A3 TDI, 04 DeVille DTS
    Join Date
    Feb 2012
    Location
    SAT, BER
    Posts
    152

    Re: P0174 on a 04 Deville

    I repeat, I capture a video/pictures on my phone for all codes so that it does not matter how quick they fly by. Since there are two different code categories, I guess he selected all codes. I am sure that I did.

    Anyway, when I tried to locate the FPR today, I made an observation. The hose identified by Submariner409 as "clean air" supply for the PCV system was not only cracked as shown by my picture yesterday but totally cracked in two (rubber elbow and plastic hose where physically separated - leaving about half an inch of empty air in between) on the other side (see picture 1):

    crackedHose1.JPG

    About half an inch of the of the plastic pipe remained in the rubber elbow. The rest was cut off clean and pretty much obstructed by the bigger hose above it. IMHO this would also explain a slight whiff of exhaust-like smell in the Deville from time to time. The friendly auto part store next door provided us with about a foot of thick rubber hose (it says fuel vapor on the hose) and I built two new connectors: one elbow

    elbow.JPG

    and one hose for the part connecting to the front:

    front.JPG

    I put the adjusted hose/piping in and the car started up purring like a car. No rough idle, not the slightest shake, and the SES light did not light up. However, since he had to drive to me, the engine was already hot so I might celebrate too early.

    Strangely for me was to learn that the elbow and plastic tube had some goo in it, it looked like dirty oil and fuel. If this was just a clean air intake, I assume this shouldn't be the case?

    Could the total separation have been the reason or am I'm not getting off that easy?

  7. #6
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    73,267

    Re: P0174 on a 04 Deville

    Any vacuum leak could have caused the problem, be it a cracked hose fitting or an unplugged hose. If you have all the hoses tight, connected and leak free I think you have solved the problem.

  8. #7
    Submariner409's Avatar
    Submariner409 is offline If it won't run, chrome it
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    74
    Posts
    44,513

    Re: P0174 on a 04 Deville

    The PCV system is subject to some really nasty oil/moisture/acid vapor movement. When you shut down or when piston ring blowby (extreme power demand operation) exceeds the flow rate of the PCV orifice (no rattle valve in your particular engine) there will be some reversion of crankcase vapors > back into the atmospheric side of the throttlebody - leading to some goo and slippery snot in the lines. Normal. Along with your annual throttlebody cleaning maintenance you might want to soak those 2 PCV lines in mineral spirits to clean them out a bit.

    EVERY one of these engines should have a vacuum line/connector inspection occasionally - PPPPPP (Prior Planning Prevents Piss Poor Performance)

  9. #8
    c_d
    c_d is offline Cadillac Owners Fanatic
    Automobile(s): 06 Beetle 2.5L Manual, 08 Audi A3 TDI, 04 DeVille DTS
    Join Date
    Feb 2012
    Location
    SAT, BER
    Posts
    152

    Re: P0174 on a 04 Deville

    Thanks, Submariner409 and Ranger. He drove the car for about 30 miles today and the SES light did not come on at all. I also observed a strange starting/idling though - just after start the car is idling at 1200 rpm which goes down a notch by the second until resting stable at 700 rpm. We'll clean the TB as instructed tomorrow. Let's see how that goes then.

    One tiny question though: I am not putting the utmost trust in the new hoses I built yesterday in the dark with a carpet knife. So when I checked my work today at daylight, he had the car running and switched it off while I inspected the stuff. The second he turned it off, I heard a noticeable hiss from around the PS reservoir or coolant reservoir (upper passenger side of the engine compartment). It stayed there for about 10 seconds. Is that normal?

  10. #9
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    73,267

    Re: P0174 on a 04 Deville

    Your cold idle is normal. 1200 RPM at cold start for about 40 seconds. Once the air pump shuts down it drops to about 900. Then at a predetermined temperature (I forget what that is) it will drop to 650.

    No, the hiss is not normal. It could be the manifold over pressurization valve not sealing. Has it backfired recently? The valve (spring loaded flapper door) is in the tunnel behind the P/S pump.





    P.S.
    This is for a pre 2000 engine as in your profile. Not a post 2000 as in your title.

  11. #10
    c_d
    c_d is offline Cadillac Owners Fanatic
    Automobile(s): 06 Beetle 2.5L Manual, 08 Audi A3 TDI, 04 DeVille DTS
    Join Date
    Feb 2012
    Location
    SAT, BER
    Posts
    152

    Re: P0174 on a 04 Deville

    Again, thank you Ranger. I have cleaned out my TB today as well as the vacuum lines. I would suggest that the guides here are - despite the experts probably being used to that - updated with a comment or two on the first minutes after a TB clean being quite rough. Today, the SES light blinked for about 8 seconds and the owner was almost having a stroke because of that.

  12. #11
    MoistCabbage's Avatar
    MoistCabbage is online now Cadillac Owners 10000+ Posts
    Automobile(s): Crimson 2001 Seville STS, 1990 Seville (RIP)
    Join Date
    Sep 2010
    Location
    East Boston MA.
    Age
    26
    Posts
    21,328
    A severe misfire after a TB clean is not normal. It was probably caused by too much cleaner ending up in the intake.

  13. #12
    Manic Mechanic is offline Cadillac Owners Fanatic
    Automobile(s): 2001 DeVille
    Join Date
    Sep 2011
    Location
    Magnolia, TX (NW of Houston)
    Age
    44
    Posts
    405

    Re: P0174 on a 04 Deville

    After any throttle body cleaning or chemical sprayed into intake you should start the engine as follows. Turn key to "on", press throttle pedal to floor, crank engine until it starts, release pedal. If the engine immediately stalls then repeat. This will prevent back fires and rough running from pooled chemical.

    Vernon

  14. #13
    MoistCabbage's Avatar
    MoistCabbage is online now Cadillac Owners 10000+ Posts
    Automobile(s): Crimson 2001 Seville STS, 1990 Seville (RIP)
    Join Date
    Sep 2010
    Location
    East Boston MA.
    Age
    26
    Posts
    21,328
    FWIW, a Northstar (and most other GM engines) won't start under full throttle. The injectors are disabled if the TPS reads anything over 80% throttle - "clear flood mode".

  15. #14
    Ranger's Avatar
    Ranger is offline Cadillac Owners Member
    Automobile(s): White Diamond '03 DHS (with DTS floor shift)
    Join Date
    Jun 2004
    Location
    Woodstock Ill.
    Age
    66
    Posts
    73,267

    Re: P0174 on a 04 Deville

    Hehe, I can imagine that may have put you in the OMG, WTF did I do mode. I usually stuff a rag back in the TB and just into the manifold to sop up as much of the solvent as I can after the TB cleaning to prevent that. Just about as far as I can reach with my finger (not doable on all engines). You could also use a brake bleeder to suck some out or just block the throttle plate open for an hour or so to let it evaporate if you are concerned about it. More than one way to skin this cat.

  16. #15
    c_d
    c_d is offline Cadillac Owners Fanatic
    Automobile(s): 06 Beetle 2.5L Manual, 08 Audi A3 TDI, 04 DeVille DTS
    Join Date
    Feb 2012
    Location
    SAT, BER
    Posts
    152

    Re: P0174 on a 04 Deville

    Good morning - personally, I was not too concerned - my Seville trained me well in that regard. I can confirm that there was a lot of cleaner in the system - the Deville has 130k on its back, all city, and the TB was never cleaned (according to the owner). There was a lot to clean to say at least. However, I was amazed how easy the procedure was though, totally non-Cadillac :-)

    I just recalled another question I wanted to burden you guys with: I observed that the gas pedal pull line was sitting tightly in that little throttle rotor but the cruise line (?) was sagging a lot. Could that cause the other code with the cruise control? PCM P1585 C - cruise control inhibit output circuit

+ Reply to Thread
Page 1 of 13 1 2 3 4 5 6 7 8 9 10 11 ... LastLast

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting