1999 Cadillac DeVille - Page 5 - Answered Questions & Fixed issues

When was the last time you change the thermostat and do a coolant flush?
The regular schedule is every 2 years or 24,000 miles.

Do not drive the car because over heat can warp the Northstar V8 aluminum head and blow the headgasket.
Do the thermostat change + flush and fill ASAP.

Hi there. Sounds like it could be fuel pressure. Did you try unscrewing the cap on the fuel rail to see if fuel sprays out or just drips? I'd check that first..

No reset - there is a problem with the traction control system which turns the light on. Check the trouble codes (DTCs) to find out what the problem is.

Hello Bridy, It is telling you to make sure the gas cap is tight. If that does not help, I would try a new gas cap.

Hello Jamal, I had a catalytic converter go bad. I took it to a muffler shop. They put the car on a hoist while engine was running and used a cutting torch to blow a small hole before and after the converter to compare back pressures. My converter was plugged up .

That may be an optional function. You may have to reprogram that option. Some doors lock when the car is put in "Drive" others when the car exceeds a certain speed ...and you may have the option on the Caddy to do either or ...not have the locks do anything. How, exactly, you do it on your Cad I don't know. Check the owners manual if you have it. Here's a downloadable .pdf for the manual: http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CB8QFjAA&url=http%3A%2F%2Fwww.vadengmpp.com%2Fowners-manual%2Fcadillac%2F1999-Cadillac-Deville.pdf&ei=dT0MVcW8AvX_sATo-4GYCg&usg=AFQjCNFNsFM9dRUiUZBbRmRAk2MFFIqt3w&bvm=bv.88528373,d.cWc Check out some Caddy-specific forums...yours is not the only car with this problem. A quick Google search hopefully to get you pointed in the right direction: https://www.google.com/search?q=%2799+deville+door+lock+settings&ie=utf-8&oe=utf-8#q=%2799+deville+door+lock+problems

When its cold remove the rad cap, start it up, put your heater blower on full and full heat on, then when the engine gets hot look inside the rad you should see the water flowing. If its not flowing feel the top of the thermostat housing/rad hose it should be nice and hot, it its not your stat is not opening. Are you sure you got the correct temp stat for this car? Was it properly installed and is the system full with no air in it? You can also get a melt stick from your local Napa, making sure its the right temp stick for your car, put it on the stat housing and see if it melts. If it does and you still have no flow either its stuck closed, or its the wrong temp stat.

It means there is a leak in the evaporative emission system . P0442 OBD II Trouble Code

If the cable is broken or the latch is stuck, you will probably have to remove the lower air shield at the front of the car and reach up and manually release it. If it is just stuck, you can try gently bouncing the front of the hood while pulling up on it while someone is pulling on the release. When you get it open, lubricate the latch assembly.

The powertrain control module (PCM) doesn't like the information it is getting from the ignition control module (ICM), and the PCM controls shifting, traction control, etc.If these are the only codes you are getting and the car moves, then you could assume the sensors connected to the ICM are working properly. That leaves why the PCM thinks there is a problem. I would certainly replace the ICM first, and then if the problem still exists, the PCM.

Here is a short video of the process

That is an easy fix, it is one of two issues. (1) Check the fuse for the dash lights. If the fuse is ok , it will be (2) burnt out bulbs. For #2 - you have to remove the bezel surrounding the dash cluster. Then look to see if the bulbs are good or have burnt out. The new bulbs are available at almost any auto parts store.

Someone has to drop the gas tank to access the pump assembly inside.

poor choice if purchased. The head bolts tend to break and to have it repaired is very costly for they are slender and long. . A 99 Cadillac is too old for they have many modules operating this vehicle and the shocks themselves run nearly $1000 each. Back off on this deal

Take a good look at the alternator plug. The tabs on the inside should all look the same. Also a lot of corrosion can cause no contact. Replace the plug if necessary.

You will have to wait the three minutes. During that time clean the key with an alcohol pad. Works for me.

Sea Foam will clean your engine - intake, injectors, combustion chamber, etc. "Hi Test" will not. Higher octane fuel actually has higher resistance to exploding. High compression engines need higher octane to prevent 'pre-combustion' or detonation (explosion). Diesel engines do not have a spark plug and rely on diesel fuel detonating due to the very high compression (sometimes 2.5 times what you see in gasoline engines). When octane is not high enough, just the compression stroke will cause the gasoline to detonate on its own prior to the spark plug firing, causing pinging or knocking. So, DON'T USE 'HI-TEST' gasoline to clean out your engine - it will NOT perform that function for you!!!

I think an auto parts store or dealer has to program it.

Do you have the dash light dimmer control turned off by mistake? If not test the dimmer control with a volt meter.

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