What will my audi do if i have a bad tcm? - 1997 Audi A6

The cost to replace the transmission control module (TCM) on a 2003 Audi A4 can vary depending on several factors, such as the location of the repair shop, the extent of the damage to the TCM, and the cost of the replacement part.
On average, the cost of replacing the TCM for a 2003 Audi A4 can range from $500 to $1,500. This cost includes the cost of the replacement part and the labor involved in the repair. However, depending on the extent of the damage to the TCM or if other parts need to be replaced along with the TCM, the cost can go up significantly.
It's always a good idea to get a quote from a reputable repair shop before proceeding with any repairs. They can provide you with a more accurate estimate based on the specific details of your situation. Additionally, if your Audi A4 is still under warranty, the cost of the repair may be covered, so it's worth checking with your dealer to see if this is the case.

Question edited for clarity, 'year make model' FIRST.

Larry provides a great answer (as always :>)

Larry Ng Sep 20, 2022

3.0l V6 IN FRONT? 7 GEARS BOX.
the $64,000 question asked a zillion times
there is no hard fast answer on automatics!
see all those seals inside the box.
and if just 1 or more leaks ATF, pressures fall, and will not shift correctly.
so you scanned the PCM/TCM first, and got errors, not told?

on modern boxes the pressure from the pump is modulated (EPC) by the TCM and if the sensor reads wrong;, the sensor is bad or the modulator is bad or you have HUGE leaks inside.
got 400kmeters? odometer on this car/box/
the book on the transmission

read the page on pump pressure testing
we do the tests, first. (after scans)
the test for pressure is done in all gears
PRNDL , and checked top spec.
if reads ok the pressure sensors is fibbing
if reads wrong the pressure sensor is telling truth.
do that test in the tranny book
I use ATSG manual (books).
On Some boxes we have bank if pressure switches that verify each gear actually select.
by pressure each.
even 7 of them for 7 gears.
not scanning the TCM first is a bad act.
do all the tests in the
DSG-7 DL501 0B5 S-Tronic

first, TCM errors matter first, even blow fuses.

CVT FAILURE
GET IT SERVICED, p17XX ALL TRANSMISSION, CAUSED OR TCM PROBLEMS OR SENSOR TO IT DEAD.
OR WIRING PROBLEMS TO IT
CVT
P1757 - Supply Voltage Open CIRCUIT - Intermittent
NEWS FLASH 2014

Audi has confirmed the continuously variable transmission (CVT) is now dead,(SMOG REASONS)
A FULL FLUID CHANGE TOO GOOD, FOR BAD.ATF. IT GETS DIRTY VERY FAST.

Where is the TCM on 2003 Audi A4 1 8t located

IN ANOTHER post I read
Remove the RH seat, rear seat bottom, and plastic trim holding the right side carpet down, unbolt the seatbelt from the floor, and the carpet will pull up easily. Transmission computer is in a plastic box under the carpet there.

code p 1625 refers to CAN databus, TCM--incorrect signal===causes --TCM trouble code/s stored---TCM incorrectly coded---wiring---matching resistor in ECM
I don't have a listing for code p 1749 but codes 1748 and 1750 are concerned with TCM defective and voltage supply low
so after you check the wiring and connections form the transmission you have 2 options
use a known good ECM to replace yours ( will eliminate any ECM faults)
and/or replace the TCM module on the transmission

Dealer price is around $2500 for the TCM and installation.

2003 Audi A6 Misc Electrical Parts 01 02 03 04 AUDI A4 A6 Transmission Control Module TCM REPAIR KIT WE...

with all those symptoms you will be able to get some codes about the problem. once you get the codes you can get a follow up proses by knowing what part or system is no working.
you need to find a scanner that is capable to read transmission codes.

Your automatic gearbox is going in "limp home mode". You need to check first the oil level. Change oil if necessary.

If the problem still occurs you shoud access the Transmission Control Module (TCM) using diagnostic equipment connected to the Data Link Connector (DLC) of the car. Then you will be full informed about the root cause of the problem, and you can replace bad pieces & reset the TCM electronic unit.

Trouble code identification:
VAG type 5-digit fault code 18034 = EOBD type P1626 fault code:
Fault location = CAN data bus, TCM - no signal
Probable cause = TCM trouble code(s) stored, TCM incorrectly coded, wiring, matching resistor in ECM.