1998 Cadillac  STS.
North Star V8
Check Engine Light on
GM Computer codes = P0741 TCC stuck off.

Question = I just got back from the GM Dealer as I had my car in because the
check engine light was on for 5 days. He came up with codes stored P0741, AND
P1611. Also P1599. P1611 is related to SES light Code P0741 is Transmission
code and there was no time to take it to transmission Department for Diagnosis
for code P0741.
When I picked the car up and paid for diagnose the Light was still on .
Drove back in to be told that it is possible I might need a new transmission !!!
Want me to bring the car back.
The car runs beautifully and it shifts as smooth as a babies bum .
Can you help with this information. Do not worry about the code P1599 as
supposedly air cleaner baffle leak.


JK:
Thank you for your tip / donation.
Code p0741 is Torque Converter Clutch (TCC) excessive slip. There is actually
a service bulletin for this code that usually fixes it. The trans would have to come
out and disassembled to look for worn seals from slippage of the drive sprocket
bearing inner race on the drive sprocket. With nearly 100k miles on it, then an
overhaul would most likely be needed, since the trans. Would be out and apart.
For you reference, the bulletin # is 04-07-30-034.P1611 is a problem in the
Continuous Variable Real Time Damping (CVRTD) serial data from the
Continuously Variable Road Sensing Suspension (CVRSS) system to the PCM.
This code usually points to another problem. Being that it is a communication
code with no other related codes, it most likely not something to worry about.
There are sometimes communication codes stored in these cars computers
when there is no problem. So i would not to be concerned with it.
1998 Cadillac Deville.
Warning lights = check engine light P0741 and P1258.
Question = Does any one know what I have to do for the following codes on a 1998 Cadillac Deville 1)P1258 -
Engine Coolant Over temperature - above 268°F - Protection Mode Active  2) P0741 - TCC System Stuck Off.
Answer: For the TCC stuck off- see above.
P1258 is set because the engine is overheating, or the Powertrain control
Module (PCM) thinks the engine is overheating. You need to diagnose a
basic engine overheating condition.
1. Low coolant caused by a leak.
2. Head gasket problem.
3. Radiator fans don't go on.
ETC.
2000 Cadillac Deville Northstar V8
Replaced thermostat and water pump.
Question = my car has 125thousand miles on it its been babied its whole 11yr life and stored in a garage
also anyway it started overheating so i repaired the thermostat that didn't fix it so I figured the next logical
step would be replace the water pump so i did that and its STILL overheating  every time i drive i have to
put between a gallon and a gallon and a half of coolant in it I've been told i mite have a pinhole in the
head gasket I'm not convinced though i love my car so PLEASE help direct me on what to do next.
Answer: If you are losing that much coolant, and don't see it on
the ground, you could definitely have a bad head gasket. Even
worse, you could have a cracked cylinder head or block. This
type of condition would really need to be checked out. The
cooling system can be pressure tested to see if any leaks are
found that way. There is also a cylinder leak down test that can
be done. Either of these would need special tools and a
qualified technician. Even though you say your car has been
well taken of, the Northstar engines are notoriously bad for oil
leaks and cylinder head problems. If you end up needing head
gaskets or more, be prepared for it to be very expensive!