P1743 on Audi: How to Diagnose & Fix
Torque Converter Clutch Solenoid Failed On
1 Audi model · 1 documented issue · 1 critical
P1743 on Audi by model: symptoms, diagnosis and fix
Audi TSB 2013280/4 addresses a specific loss-of-pressure condition in Multitronic transmissions produced from May 2005 through May 2006. The vehicle may not move or may engage Drive or Reverse only after a delay and increased engine speed; P1743/18151 may be stored. Audi attributes the covered condition to production-damaged axial seals, but its repair depends on the selected direction and measured transmission values. The previous card incorrectly treated every 2005-2011 C6 A6 transmission complaint as inevitable chain/hydraulic failure, claimed complete replacement was usually the only economical repair, mixed transmission families, and linked a generic rebuilt-mechatronic search. This corrected record applies only when the vehicle actually has the front-wheel-drive 01J Multitronic and falls in the bulletin's production window.
Common Symptoms
- No movement or delayed movement after Drive is selected
- No movement or delayed movement after Reverse is selected
- Engine speed must be raised before the vehicle begins to move
- P1743/18151 clutch-slip-monitoring fault may be stored
How to Fix
First identify the transmission code and vehicle production date; Quattro/09L and other transmissions are outside this repair. Scan the TCM and retain the printout. For P1743/18151, Audi directs the technician to inspect MVB 44/1 and 45/1: 1000 mA with pressure above 12 bar points to the axial seals, while pressure below 12 bar indicates a different hydraulic problem. If no fault is logged, Audi specifies an adaptation drive with ATF temperature above 90 C, then assessment of MVB 10/1. For a Drive complaint with MVB 10/1 above 380 mA, the bulletin calls for four valve-body axial seals 01J301547F. For a Reverse complaint, it calls for those four valve-body seals plus input-shaft seal 01J301547A and the corresponding transmission work. If the production range, direction, DTC, temperature, or measurements do not match, continue Guided Fault Finding instead of buying seals or a transmission. These are internal, condition-dependent parts; verify current Audi supersessions and quantities through the VIN before repair.
Owner tips & cautions
- WarningDo not assume an A6 has Multitronic from the model year alone. Confirm front-wheel drive, transmission code 01J, and the May 2005-May 2006 production window before using this bulletin.
- TipAsk for the TCM scan, ATF temperature, complaint direction, and MVB 10/1, 44/1, and 45/1 values in writing. Those values determine whether the seal repair applies.
- WarningThe old rebuilt-mechatronic search was removed. Audi's bulletin does not authorize a mechatronic unit or complete transmission merely from delayed engagement, and ShowMeTheParts has no axial-seal candidate for this YMME.
Sources for this issue (2)
P1743 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P1743 mean on a Audi?
P1743 stands for "Torque Converter Clutch Solenoid Failed On." A manufacturer-specific transmission code used by Ford (and Ford-built Mazda applications). The powertrain/transmission control module commanded the torque converter clutch off but the monitored solenoid circuit indicated it stayed in the applied (on) state. Because the converter can stay locked, the engine may not decouple from the transmission at low speed, so the car can shudder or stall when coming to a stop, and the transmission may go to a failsafe strategy. Ford uses the neighboring code P1742 for the mechanical/hydraulic version of the same 'failed on' condition, so read both codes together before condemning a part. On Audi it is documented across 1 model: A6.
What are the most common causes of P1743?
The most common causes of P1743 are: Failed or stuck-on torque converter clutch (TCC) solenoid, Low or contaminated transmission fluid affecting solenoid operation, Shorted or open wiring / connector corrosion in the solenoid circuit, Debris or a stuck valve in the valve body, Clogged transmission filter, Failed torque converter clutch itself, Faulty TCM/PCM solenoid driver circuit. The specific cause varies by vehicle.
How much does it cost to fix P1743 on a Audi?
Repair costs vary widely with the root cause and Audi model; each issue on this page carries its own estimate where one is published.
Looking for P1743 on a different make?
View P1743 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.