My check coolant light comes on every now and then. One morning I checked it was at 1/3 tank. The next time I checked it it was an inch from the top of the tank. Am I crazy. The check coolant light has been coming on more frequently this week but every time I check it is an inch from the top.
What is going on?

By the way ** How much coolant should be in the tank **. I dont see a line on the tank to pour to.

Also how do I check codes on my 01 deville? I did a search but I did not find for my year & model.





01' Deville
Dex-Cool 50/50

Based on comments on the forum, this appears to be a relatively common problem. In my case, I believe the sensor in the overflow/surge tank is bad. The level has remained about an inch from the top for the past three months, regardless of the "Check coolant" light on the DIC.

The sensor is an integral part of the surge tank. I just haven't gotten around to replacing it. As long as you KNOW the coolant level is OK, I'd either ignore it, or replace the tank.

I use the "can my fingertip touch coolant" method - take off the surge cap (when cold) and stick the ol' index finger down the neck. If I can touch coolant, it's OK.

I believe the DIC code entry process is to simultaneously press the (climate control) OFF button and the PASSENGER WARM(er) button, or passenger temp UP button.

....
Also how do I check codes on my 01 deville? I did a search but I did not find for my year & model.





01' Deville
Dex-Cool 50/50

Here is more than you wanted to know about DTC display for your year/model.

************************************************** ********

DTC display; 1998-2004 Seville and 2000-2005 Deville


Use the 3 switches located to the right of the Driver Information Center (DIC) to activate and respond to the OBD prompts on the DIC.

ON/OFF = YES
INFO RESET = NO
INFO DOWN or INFO UP = manual toggle


Ignition ON, acknowledge any warning messages; press ON/OFF and INFO UP together for 2 to 3 seconds. Everything in front of you lights up for 4 or 5 seconds, then you will see:

Display shows "ALL?"

Answering YES will display "ALL CODES?"
Answering YES will run automatic test sequence and display codes, if any. Systems and codes will scroll faster than I am able to read them and write them; not to worry.
"ALL CLEAR CODES?" will display at the end of the automatic test. If you are satisfied you have the information you need, answer YES to clear/erase all error codes.


Answering "ALL?" with INFO DOWN will toggle systems test manually in order.
Answering "ALL?" with INFO UP will toggle system test manually in reverse order.

Press INFO RESET to reset DIC to "ALL?" to start again.

Ignition OFF to exit.


SYSTEMS: (as of 1998)

ABS (Antilock Brake System)
AMP (Amplifier)
DDM (Door Driver Module)
DIM (Dash Integration Module)
IPC (Instrument Panel Cluster)
IPM (Instrument Panel Module)
IRC (Integrated Radio Module)
PCM (Powertrain Control Module)
RFA (Remote Function Actuation)
RIM (Rear Integration Module)
SDM (Sensing and Diagnostic Module) Includes airbag crash data. Under RF seat of Seville.
VTD (Vehicle Theft Deterrent)
MSM (Memory Seat Module)
TTM (Tilt/Telescoping Module)
RSS (Road Sensing Suspension)

last edited 12/27/04 jwd

Jim that is a relief to know, I was under the impression that Caddy's 2004 and up did not come with Self Diagnostics that the customer can read, I am pretty sure the CTS does not come with any. Thanks for clearing up that little mystery.

Yeah, someone just posted in another thread that '03 was the last year for onboard diagnostics (readable via the dash, that is).