2001 Cadillac Deville Codes

For what it takes to remove the transmission, you do only want to do it once. P0741 is TCC stuck off, and it is due to excessive TCC slip speed. This is a common problem with this era of Cadillacs. What you are going to need is a torque converter, and all the seals for the TCC hydraulic circuit, most critical is the teflon seals that are in the channel plate. It is best to get a complete seal/gasket kit, as you will pay close to about half of it's price, or more, to piece all the seals together. Replace the TCC solenoid, as it is probably the cause of the P1860 as well. The engine is going to need supported with a fixture from above, as you will be removing the frame, to then remove the transmission. The two 18mm bellhousing bolts on the top are well hidden under the water pump housing and wire harness, so you will need to gain access to them. You can remove the upper valve body, and pump assembly in individual units with the side cover removed. Don't separate the pump exposing the gears, or at least if you do, pay attention to marks on the gears. If they are installed incorrectly, you will break pump shafts for no apparent reason. As far as the other codes, p0410 relates to secondary air injection, could be air pump connector, air pump, or vacuum lines in most cases. P0420 is catalyst efficiency, and usually if it is present or returning, you may need a catalyst. Also, if you have oil leaking from the lower crankcase, you may opt to make that correction at the same time.

Not certain on the cluster flashing out, there are fuel gauge concerns that usually relate to faulty sending unit cards.

It won't cause any damage, it is basically letting you know that damage would occur if it were to continue operating the TCC, therefore it is disabled.

WHEN THE CAR IS FULL IT WILL FLASHS E UNTIL U DRIVE IT AND THE GAUGE READS PROPERLY. REMOVE THE FUEL TANK AND REPLACE THE SENDING UNIT AND THE FUEL PUMP WHILE YOUR IN THERE. THE PUMP HOOKS TO THE SENDING UNIT. DRIVE IT ITS OK TOO.