P0741 on 2000-2002 Audi S4 2.7T: Torque Converter Failure Causes and Fixes

What's Unique About the 2000-2002 Audi S4

The 2000-2002 Audi S4 (B5 generation) with the Tiptronic automatic uses a ZF 5HP19FLA transmission. For this specific powertrain, P0741 is a notoriously common code that almost always points to a single, well-documented failure: a bad internal seal within the torque converter. While on other vehicles this code might suggest a faulty solenoid or fluid issue, on the B5 S4, these are rare causes and often misdiagnoses. The problem is so common that Audi issued a Technical Service Bulletin (TSB 32-07-02 / 2010879) acknowledging the internal torque converter failure as the root cause for this code on this transmission family. Another TSB (32-08-05) also addresses an improved torque converter oil seal.

Symptoms You May Notice

• Check Engine Light (MIL) is on
• Engine RPM fluctuates or 'bounces' slightly (200-300 RPM) at steady highway speeds (50-70 mph)
• Reduced fuel economy
• A shuddering or vibration felt during acceleration or at highway speeds, sometimes described as driving over rumble strips.
• In some cases, the transmission may feel like it's slipping or shifting may be delayed.
• Transmission may overheat, especially under load, which can lead to more severe internal damage.

Most Likely Causes

1. Failed Internal Torque Converter Seal 🔴 High Probability → Shop Automatic Transmission Torque Converter The ZF 5HP19FLA transmission used in this vehicle has a known design weakness where the internal seal for the lock-up clutch assembly becomes brittle and fails, preventing the system from building enough hydraulic pressure to engage the clutch. This is a mechanical failure inside a non-serviceable part.
   How to confirm: Use a diagnostic tool like VCDS to monitor Measuring Blocks in the Transmission controller (02-Auto Trans). Go to Group 007 and observe the second field, which shows TCC slip RPM. While driving at a steady highway speed, if the slip is high (over 100-200 RPM) when lock-up is commanded, the converter is failing. 🎬 Watch: Troubleshooting a 5HP19 torque converter on a B5 S4 A visual inspection of the transmission fluid may show it is dark or burnt.
   Typical fix: Replace the torque converter. This requires removing the transmission from the vehicle. Some owners have had to replace the converter multiple times, suggesting that even replacement parts can fail.
   Est. part cost: $400-$800
2. Low or Degraded Transmission Fluid ⚪ Low Probability → Shop Transmission Assembly
   How to confirm: Check the transmission fluid level and condition following the correct procedure (fluid must be at a specific temperature, typically 30-40°C). If the fluid is very low, dark black, or smells burnt, it indicates a problem.
   Typical fix: Perform a transmission fluid and filter service. However, this is rarely the final fix for this code on this car and often only a temporary measure if it helps at all. Some owners report that changing old, thick fluid can sometimes make slipping worse.
3. Faulty Torque Converter Clutch (TCC) Solenoid ⚪ Low Probability → Shop Automatic Transmission Torque Converter
   How to confirm: The solenoid (also known as N218 or EDS 4) can be tested for proper electrical resistance with a multimeter. This requires dropping the transmission pan and valve body to access it. The expected resistance is between 6.2 and 7.8 Ohms.
   Typical fix: Replace the TCC solenoid. This is a very common misdiagnosis for this platform. Forum users report replacing the solenoid only to have the P0741 code return, confirming the issue was the converter itself.

Rare But Worth Checking

• Worn Valve Body: → Shop Transmission Valve Body On the broader ZF 5HP19 family, a worn pressure regulator valve bore in the valve body can cause pressure spikes that contribute to the failure of the torque converter seal. Some specialists recommend installing an aftermarket repair kit (e.g., from Sonnax or TransGo) in the valve body when replacing the converter to prevent repeat failures. One owner on Reddit reported trying this upgrade after multiple converter failures.
🎬 Watch: How to install a ZF 5HP19 pressure regulator upgrade

Diagnosis Steps

1. Scan the Transmission Control Module (TCM, Address 02) with an OBD-II scanner (preferably VCDS) to confirm P0741 (or 17125) is present and to check for any other related codes.
2. Check the transmission fluid level and condition. This must be done with the engine running and the fluid at a specific temperature (use a scan tool to monitor temp), with the vehicle level. Fluid that is black, smells burnt, or full of debris indicates a serious internal problem.
3. Perform a road test with VCDS or a similar scan tool connected. Select the Transmission controller (02) and go to Measuring Blocks (08).
4. Enter Group 007. The second data field displays the real-time Torque Converter Clutch Slip in RPM.
5. At a steady cruising speed (e.g., 55-65 mph in 5th gear), observe the slip RPM when the TCC status shows 'Locked'. If the slip is consistently above 50-100 RPM, it confirms the clutch is not holding and the torque converter has failed internally.
6. Given the high probability of torque converter failure on this specific vehicle, if significant slip is confirmed, the diagnosis is complete. Further electrical testing of the solenoid is usually unnecessary and likely a waste of time and money.

Parts You'll Likely Need

• Torque Converter (OEM #01V323571F (or superseding part numbers)) — This is the primary point of failure for code P0741 on the B5 S4 due to a well-documented internal seal failure.
  Trusted brands: ZF (OEM), Sachs, LuK, TC Remanufacturing
  OEM price range: $600-$900
  Aftermarket price range: $350-$700
• Automatic Transmission Fluid and Filter Kit — The transmission fluid (Audi P/N G052162A2 or equivalent) and filter must be replaced when the torque converter is serviced.
  Trusted brands: ZF, Vaico, Febi, Pentosin
  OEM price range: $150-$250
  Aftermarket price range: $80-$150

Related Codes That Often Appear With This One

• P0740 — P0740 is a more general 'Torque Converter Clutch Circuit Malfunction' code. They often appear together as they relate to the same system.
• 17125 — This is the VAG-specific (Volkswagen/Audi Group) equivalent of the generic P0741 code. An Audi-specific scan tool like VCDS will display this code.

Technical Service Bulletins (TSBs) & Recalls

• TSB 32-07-02 (also listed as 2010879/10): Confirms that DTC 17125 (P0741) on the 01V (5HP19FLA) transmission is caused by an internal torque converter failure, requiring replacement.
• TSB 32-08-05 (2018239/2): Mentions an 'improved torque converter oil seal' as a production solution, further acknowledging the seal as a weak point.

Platform-Specific Known Issues

• The ZF 5HP19FLA automatic transmission is known for this specific P0741 failure mode across multiple VAG vehicles that use it, not just the Audi S4.
• Ignoring this code will lead to transmission overheating, which can cause clutch pack and other internal component damage, turning a torque converter job into a full transmission rebuild or replacement.

Mechanic-Grade Diagnostic Values

• Torque Converter Clutch Solenoid (EDS 4 / N218) Resistance — expected: 6.2 - 7.8 Ω. Failure: A reading outside this range (open or shorted) indicates a failed solenoid. However, passing this test does not rule out a mechanical failure in the torque converter.
• Shift Solenoid (MV 1, MV 2, MV 3) Resistance — expected: 30 - 34 Ω. Failure: A reading outside this range indicates a failed shift solenoid. These are less relevant for P0741 but are useful for general transmission health checks.
• Pressure Regulating Solenoid (EDS 1) Resistance — expected: 5.2 - 6.8 Ω. Failure: A reading outside this range indicates a failed pressure regulator solenoid.

Wiring & Ground Locations

• Transmission Case Connector — On the transmission housing, typically on the side. It's a large, round, multi-pin connector.. The TCC solenoid (EDS 4) is controlled via Pin 11 and Pin 12 of this connector. Resistance can be checked between these pins from outside the transmission, without dropping the pan, to quickly test the solenoid's electrical integrity.
• Engine/Chassis Ground Points — Main grounds are located on the frame rail near the driver-side fuse box and on a bolt attaching the throttle body to the intake manifold.. While not a primary cause for P0741, poor ground connections can cause a variety of electrical issues and voltage drops that may affect TCM operation, though it's highly unlikely to be the root cause of this specific, mechanical-failure-prone code.

Real Owner Repair Stories

• AudiSRS.com forum user (Audi S4 with ZF 5HP19FLA transmission) — P0741 code, burnt ATF
  ❌ Tried (didn't work) Replacing the TCC solenoid (N218), Changing the transmission fluid
  ✅ What actually fixed it The issue persisted after replacing the solenoid. The final fix required replacing the torque converter itself due to a worn internal clutch that would slip under load, confirming the mechanical nature of the failure.

OEM Part Supersession History

• 01V323571F → This is a common base part number. Subsequent letters (like 'G', 'K', etc.) indicate revisions. It's critical to use a part number compatible with the specific transmission code (e.g., 'FAU' for the S4). — Revisions often aim to improve the internal seals that are the known failure point.
  Heads up: While many ZF 5HP19 torque converters look similar, stall speed and mounting can differ. Using a converter from a different engine (e.g., a 3.0L A4) can cause performance issues or may not fit. Always verify the part number against the vehicle's VIN and transmission code.

Model Year Variations Within This Range

• 2000-2002: There are no significant documented mechanical differences within the 2000-2002 B5 S4 Tiptronic transmission (ZF 5HP19FLA) that would alter the diagnosis or cause of P0741. The issue is consistent across the entire B5 S4 automatic production run.

Diagnostic Flowchart

Other Known Issues on This Vehicle

Issues unrelated to this code that are worth knowing about as an owner of this generation:

• Stock K03 Turbocharger Failure 🔴 High — Common, especially on vehicles over 100k miles or those that have been tuned. Failures are often due to heat soak from their location between the engine and firewall.
• Front Control Arm Bushing Wear 🟠 Medium — The multi-link front suspension has numerous bushings that wear out, leading to clunking noises, poor alignment, and sloppy handling. Replacement is a common maintenance item.
• Timing Belt Service 🔴 High — This is a critical maintenance item, not a failure. The timing belt, water pump (with failure-prone plastic impeller), and tensioners require replacement. It is a labor-intensive job requiring the front of the car to be disassembled.
• Valve Cover and Cam Tensioner Gasket Oil Leaks 🟠 Medium — The 2.7T engine is notorious for oil leaks from the valve cover gaskets, half-moon cam plugs, and the seals for the cam chain tensioners.
• Auxiliary After-Run Coolant Pump Failure/Leaks 🟡 Low — The small electric pump that circulates coolant to the turbos after shutdown is prone to leaking or failing. Due to its location under the intake manifold, it is difficult to access. Many owners opt for a delete kit.
• Instrument Cluster Center Display (DIS) Fading 🟡 Low — The pixels in the central digital display in the instrument cluster commonly fail, making it difficult or impossible to read.

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: For this specific P0741 failure, a used torque converter is NEVER a smart choice. The failure is a known design and wear issue, so a used part is highly likely to have the same defect or fail shortly after installation. A used complete transmission assembly from a low-mileage, documented donor car can be an option if the cost is comparable to a torque converter replacement job, but it carries the same inherent risk.

Donor-vehicle mileage cap: roughly under 60000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• For a complete transmission: verify the donor vehicle's mileage and history if possible.
• Inspect the fluid from the donor transmission. If it's dark, burnt, or contains metal, reject the part immediately.
• Ask for a warranty, even if it's just 30-60 days, to protect against an immediate failure.

OEM-only on this vehicle (don't cheap out):

• Torque Converter: Given the high failure rate, a new or professionally remanufactured unit from a reputable source (ZF, Sachs, or a specialist rebuilder) is strongly recommended over a generic, cheap aftermarket part.

Aftermarket brands forum-validated for this vehicle:

• Torque Converter: ZF (OEM), Sachs, LuK.
• Valve Body Repair Kit: Sonnax, TransGo.
• Fluid: Pentosin ATF 1, Febi, Vaico, Ravenol (must meet G052162A2 spec).

Brands owners have reported issues with on this vehicle:

• Unnamed, 'white box' or suspiciously cheap remanufactured torque converters from online marketplaces are a significant gamble.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• 17125 — This is the VAG-specific factory fault code that is equivalent to the generic OBD-II code P0741, indicating torque converter clutch circuit performance or stuck off.
• P0740 — Related to the Torque Converter Clutch (TCC) circuit; often mentioned alongside P0741 when diagnosing electrical vs. mechanical lock-up failures.
• P0730 — Incorrect gear ratio; may appear if the transmission fluid is severely degraded or if internal slipping is detected beyond the torque converter.

Frequently Asked Questions