p1520 Trans Circuit
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
Results 1 to 7 of 7
Northstar Engines and System Technical Discussion Discussion, p1520 Trans Circuit in Cadillac Engine Technical Discussion; I've got a '97 SLS that was having trouble shifting the last time I drove it. I did a WOT ...
  1. #1
    digitalcaddie is offline Cadillac Owners Fanatic
    Automobile(s): '02 Escalade
    Join Date
    May 2005
    Posts
    201

    p1520 Trans Circuit

    I've got a '97 SLS that was having trouble shifting the last time I drove it. I did a WOT to get to 80mph on the interstate, but then the rpms stayed at 3000+ when I started cruising like the overdrive never kicked in or it never shifted to 4th gear. The car continued to shutter and was having problems finding the proper gear. The SES light came on from code p1520 transmission range switch circuit. There are a lot of posts on here from people tripping that code, but there is very little about how to fix it or what the problem is. A couple people went to the dealership...is that my only option? Should I go to the dealership or a tranny shop? Can someone post about how/what they did to fix this issue?

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    digitalcaddie is offline Cadillac Owners Fanatic
    Automobile(s): '02 Escalade
    Join Date
    May 2005
    Posts
    201
    Thread Starter

    Re: p1520 Trans Circuit

    Different question...where do you check/add transmission fluid?

  4. #3
    Submariner409's Avatar
    Submariner409 is offline If it won't run, install a sound system
    Automobile(s): 2002.5 F55 STS/65500mi, 2004 Ford F150 SuperCab4x4
    Join Date
    Feb 2006
    Location
    MD Eastern Shore - Kent Island
    Age
    74
    Posts
    45,589

    Re: p1520 Trans Circuit

    The transmission dipstick is (standing in front of the car looking down into the engine compartment) on the right side of the engine assembly, down under parts of the intake tract and maybe an air intake resonator....not sure about your model.....The stick is a black twist cap with a red (?) line across the finger handle. Just right of the coolant crossover housing and upper hose outlet........

    The 4T80E is a dry sump transmission: there will be no fluid on the stick with engine off, cold. The correct level is in the middle of the hot hashmark, engine running, hot, shift cycled through P-R-N-D and back several times, back to P and check.

    If you have had no service done to the transmission recently, you can use either DEXRON-III or the new synthetic DEXRON-VI which is backwards-compatible. (GM TSB on this earlier this year.)

    Exactly in the center of the pic.......

  5. #4
    digitalcaddie is offline Cadillac Owners Fanatic
    Automobile(s): '02 Escalade
    Join Date
    May 2005
    Posts
    201
    Thread Starter

    Re: p1520 Trans Circuit

    Great, thanks. Maybe I'm just a little low on fluid. I did notice a small amount of red fluid hanging on underneath the car when I changed the oil two weeks ago. I'll have to pull the air intake and check the dipstick.

  6. #5
    digitalcaddie is offline Cadillac Owners Fanatic
    Automobile(s): '02 Escalade
    Join Date
    May 2005
    Posts
    201
    Thread Starter

    Re: p1520 Trans Circuit

    So my fluid isn't low. Its brown and smells kinda burnt which probably isn't good, but the level is right in the middle of the dipstick. I guess I'll keep searching...

  7. #6
    digitalcaddie is offline Cadillac Owners Fanatic
    Automobile(s): '02 Escalade
    Join Date
    May 2005
    Posts
    201
    Thread Starter

    Re: p1520 Trans Circuit

    So to follow-up, it appears like I've got one of the P0741 Torque Converter Clutch problems. After I cleared the codes, this code was the only one that came back. I'm not exactly sure what I'm going to do now. I was thinking about selling the car, and while I'd only like to get about $3k for it, I think I'd be lucky to get $1500 with the idiot light on due to this problem. Too bad...this car seemed to not have headgasket problems or the previous owner had the engine replaced.

  8. #7
    hnettles's Avatar
    hnettles is offline Cadillac Owners Member
    Automobile(s): '00 Deville DTS
    Join Date
    Jun 2005
    Location
    Alvin, TX
    Age
    63
    Posts
    40

    Re: p1520 Trans Circuit

    I'm dealing with the same issue on a 1999 DeVille. How exactly did you determine that you had a "P0471 Torque Converter Clutch" problem? Did your car show that code or did you take it to the dealer or a transmission shop or ???

    I'm getting P1520 and P1527 codes, 4 times in the last 3 months, but no P0471. Also, the Service Engine light has never come on.

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