the service engine light stays on on my 84 eld, the code that is shown is 39. book says a tcc engagement problem. what does that mean? the car seems to shift and drive fine. book says to check conectors at trans. did it looks ok. also said to check wire between trans. and ecm. ,but after they go into a main wire harness how do you follow them?
any help appreciated
also to let you know solved my hesitation, backfire problem with a rebuilt dist.
thanks, DNE

book says....does that mean the Cadillac FSM? If so: have you gone through the diagnostic tree? There are a number of problems that can make the 39 show up. The ECM monitors the VSS/CTS/TPS/MAP/CTM/brake switch operation......
Have you performed the ECM Switch tests?

dave, thanks for repley
at this time I only have a hanes manual.
so am not sure how to do the other test.
any other way to get information other than a FSM?
thanks,DNE

Those haynes and chilton manuals are a waste of money because they do not cover the car like the FSM. Another way? Maybe your local library? The diagnostic tree for the 39 code is lengthy due to the number of sensors/etc involved. ebay has '84 Cadillac FSMs for sale and the publisher, Helm Inc., still has brand-new manuals for sale #H2112. Having the FSM is owning the best tool a DIY'er can have and they pay for themselves almost immediately.

With the factory service manual in hand, you can monitor the TCC engagement/ disengagement thru the climate control head in on board diagnostics. An amber icon lights up and turns off whenever TCC works. If you drive above 60 MPH and lightly touch the brake pedal with your left foot, you should hear and/or feel the engine RPM difference as the TCC solenoid unlocks, then relocks the torque converter. If you do not feel the difference, then inspect the brake light switch on the brake pedal for proper adjustment first. You will have 2 switches on the pedal support. The one with the large vacuum hose is only for cruise control. The other switch enables brake lights but also disengages the TCC as brakes are applied. The pedal should keep the switch fully retracted until the pedal is depressed.

any other way to get information other than a FSM?
A subscription to alldatadiy.com

If you ever get insomnia you could search the archives here for TCC lockup problems. There are cases of people getting rid of those codes by doing tune ups and fixing vacuum lines and other simple off the wall things. You may get lucky.

Another thought. If you are in the habit of driving in 3rd then putting it in D on the freeway, you could cause the code to set yourself. This code usually sets because the engine speed and true road speed are outside the ECM parameters. The ECM memory is for a specific RPM for that road speed. If out of range 39 will set. Also does this code display two times or three while in diagnostics?

I beg to differ on those Haynes and Chilton manuals not being useful, if you are not planning to keep the car long or are working on some one elses car they are certainly better than nothing at all and as I have recently discovered the Cadillac FSM is not always 100% accurate.

Yes, better than nothing. But the haynes nor chilton will provide trouble trees and diagnostic paths to diagnose fault codes. They are designed for normal maintenence by the average car owner with minimal tools. The FSM assumes a better than average person with better than average diagnostic skills.

thanks for all sug.
the car is a weekend cruiser only and after a couple of drives the light went off no further trouble so far.
another question I have is that I need to replace back shocks, do not think the level ride system is working. can I just put on regular shocks?
all help appc.
thanks DNE

Sure you can but it will not sit level and ride badly. The rear springs were designed so that the shocks should always have 10 to 15 lb of air in them helping to support the car unlike regular cars where the spring supported the car with no help from the shock. This level ride system is fairly simple in design. On the left rear frame rail sits a level ride sensor with an arm attached to the lower A frame. As the rear goes down the lever goes up, sending a completed circuit to the air supply pump under hood. Assuming the plastic lines are not melted or cut, air is pumped into each rear shock leveling the car. So, with the key on, car off, reach under the left rear tire and with a flat blade screwdriver, pop the link off the A frame. Then push the lever fully up. Within 20 to 30 seconds you should hear the pump run and if the lines are good, the car will raise. Pull the lever down, you will hear the shock boots deflate. Common on a 25 yr old car to have cracked, leaking boots on the rear shocks and/ or cut, leaking supply lines to them.

I have newer Gabriel shocks on mine and I simply got a brass threaded TEE that allows 2 lines to be run. I TEE'd it by the rear crossmember and ran a line from there to each shock. As you know one line now goes to the left rear shock, then a line goes from that shock over to the right rear. Finding NOS DELCO air shocks is tough and price will be too high. Early 82 thru 84 Eldos with no options had regular shocks but also had springs designed for that as well.