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Audi · Known Issues

2006 Audi A4 Problems: 4 Known Issues

2006 model year · NHTSA recalls, manufacturer TSBs, and owner forum reports · Updated September 2026

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Issue summary

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2006 Audi A4 has 4 documented known issues, with 3 rated critical. The most serious are Broken Crank Sensor Harness Behind the Bellhousing Mimics a Dead Sensor ($100-$400 repair), 2005-2007 A4 2.0TFSI Cam-Follower / HPFP Diagnosis - TSB 2013147/12 and 2002-2006 A4 Factory-CVT Settlement History - Component-Specific Diagnosis. Across all issues with published estimates, repair costs range from $100 to $1,800. DIY maintenance guides at au7o.io.

In This Article

  • A4 Electrical1
  • A4 Fuel System1
  • A4 Transmission1
  • A4 Suspension1
  • Recalls6
  • FAQ
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In This Article

  • Electrical1
  • Fuel System1
  • Transmission1
  • Suspension1
  • Recalls6

All 4 Known Issues

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On the 2002-2008 Audi A4, b6/B7 A4 owners who set P0322 almost always buy an engine speed sensor (G28) first, and a share of them are back on the forums a week later with the same code and the same no-start. The reason is that on this platform the failure is often the circuit rather than the pickup. The G28 lives at the bellhousing above the flywheel ring gear, and its lead runs up the back of the engine through a zone that sees exhaust heat, oil weepage and constant vibration from engine rock. Insulation hardens and chafes, a conductor breaks inside the loom, or the connector's female terminals spread and oxidise - and any of those gives the ECM the same result as a dead sensor: zero pulses, and P0322 stored as no signal. Ross-Tech's guidance for 16706/P0322 is explicitly to check the wiring to and from the sensor and the ECM before condemning the part, and at least one documented case traced the fault to a broken signal wire far from the sensor, up in the main loom near the ECU under the scuttle panel. Owners describe an engine that cranks at normal speed and never fires, sometimes preceded by weeks of hot-restart hesitation or a stall pulling into a parking space. Both the 1.8T and the 2.0T FSI are affected, and the code often shows up alongside P0321 (implausible/erratic signal) when the circuit is intermittently making contact rather than fully open - that pairing is a strong hint that the problem is a connection, not the sensor element. On the A4 there is also a purely mechanical version of the same complaint: a replacement sensor that is not pushed fully into its bore, or whose retaining bolt is left loose, sits at too large an air gap and reproduces the no-signal fault straight after the repair. What makes this pattern worth calling out separately is the money it wastes - the sensor is cheap, but diagnosis by parts substitution is not.

Common Symptoms

  • Cranks but will not start
  • Code returns after a new crankshaft position sensor is fitted
  • Stalling when hot
  • P0321 stored alongside P0322
  • Zero RPM on scan tool while cranking

How to Fix

Start at the connector, not the parts counter. Raise the car, find the G28 at the bellhousing and unplug it. Inspect the pigtail along its whole visible run for chafe, heat damage and oil soaking, and look at both halves of the connector for spread pins, corrosion or green film; a terminal that has lost tension can be re-tensioned or the connector body replaced with a repair pigtail. With the sensor unplugged, measure its resistance across the signal terminals - an open reading condemns it - and then check continuity and insulation on the harness side back to the ECM connector, plus the shield and grounds. Wiggle-testing the loom while watching engine speed on a scan tool during cranking will usually expose an intermittent break; note that on documented cases the break was not near the sensor at all but up in the main loom by the ECU, so do not stop at the engine bay. If the wiring is good and the sensor is open, fit a Bosch or genuine Audi replacement rather than a bargain unit; poor-quality sensors are a recurring theme in the threads on this code. Whichever part you fit, seat it all the way to its shoulder in the bore and tighten the retaining bolt properly - a common "new sensor didn't fix it" outcome is nothing more than a sensor that was not fully seated. If the harness is the culprit, repair it with soldered and heat-shrunk joints or a factory repair lead, and re-route the section away from the exhaust so the same chafe point does not come back. Clear the fault, then verify with the scan tool that engine speed reads correctly while cranking and that the code does not return after several heat cycles. Parts run roughly $40-$150 for the sensor and very little for a repair pigtail; a shop will typically bill an hour of diagnosis plus an hour of labour, putting the whole job in the $150-$400 range.

Typical repair cost:$100 - $400

Research This Issue

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Community Reported
Low ConfidenceVerifiedReviewed Sep 2026

On the 2005-2007 Audi A4, audi TSB 2013147/12 applies to 2005-2006 A4 vehicles with the BPG engine and 2007 A4 vehicles with the BWT engine when the MIL is on and P2293 is stored; P0087 or P1093 may accompany it. Audi’s procedure checks fuel pressure and wear at the cam follower, intake camshaft lobe and high-pressure fuel pump. The documents do not publish a universal inspection interval and state the covered condition does not cause stalling.

This issue also affects: Audi A3, Audi A5, Audi Q7

Common Symptoms

  • MIL caused by the diagnosed camshaft/cam-follower/HPFP wear condition

How to Fix

Verify BPG or BWT engine fitment, record the MIL faults and measured fuel-pressure behavior, then follow TSB 2013147/12. Inspect the cam follower and cam lobe and replace only the follower, camshaft and/or high-pressure fuel pump selected by the bulletin’s conditional tree. The 10-year/120,000-mile extension is historical and generally expired; do not promise coverage or buy a parts kit from this record.

Research This Issue

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Manually Verified
High ConfidenceVerifiedReviewed Jul 2026

On the 2002-2006 Audi A4, the 2013 settlement covered U.S. 2002-2006 A4 vehicles originally equipped with a factory-installed CVT. It used component-specific branches: TCM for 2003-2006; valve body for 2003-2004; and transmission without valve body/TCM for 2002-2004, subject to maintenance proof. Plaintiffs alleged improper function, while defendants denied defect, wrongdoing and liability and the court did not decide the merits. The notice does not establish every CVT symptom as a failed transmission.

This issue also affects: Audi A4 Avant, Audi S6, Porsche 718 Boxster

How to Fix

Verify the VIN, original U.S. factory-CVT equipment, transmission code, faults, fluid/maintenance records and reproducible behavior. Diagnose the TCM, valve body and mechanical transmission separately and replace only the confirmed component. The historical 10-year/100,000-mile terms and November 18, 2013 reimbursement deadline are expired; do not promise coverage or buy a TCM, valve body or transmission from this record.

Research This Issue

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Manually Verified
High ConfidenceVerifiedReviewed Jul 2026

On the 2002-2008 Audi A4, the multi-link front suspension used on B6/B7 A4 models is well known for premature wear of upper and lower control arm bushings/ball joints and, in many cases, outer tie-rod ends. Owners commonly report front-end clunking over bumps, looseness in steering, shimmy at highway speeds, and abnormal inner-edge tire wear. The issue is widely documented in owner forums and repair databases because multiple arms can wear at once, making the front end feel unstable even when alignment is repeatedly corrected.

This issue also affects: Audi TT, Audi A6

Common Symptoms

  • front-end clunk over bumps
  • steering looseness
  • highway vibration or shimmy
  • uneven front tire wear
  • wandering alignment
  • knocking noise during low-speed turns

How to Fix

Diagnosis usually involves checking each front control arm ball joint and bushing for play with the suspension loaded, along with inspecting tie rods and verifying alignment. The durable fix is replacing the worn arms as a matched kit rather than one-by-one, followed by a proper four-wheel alignment. If pinch bolts are seized, additional labor is often required, and sway bar links should be inspected at the same time.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

  • Suspension Control Arm and Ball Joint Assembly
    Cross-refRK100092

    Fitment confirmed against the ShowMeTheParts catalog for this vehicle's year and engine.

    Amazon

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$700 - $1,800

Research This Issue

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Community Reported
High Confidence
NHTSA Recalls6 recalls

AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE

Volkswagen Group of America, Inc. (Volkswagen) is recalling certain 2005-2008 Audi A4 Sedan, A4 Avant, S4 Avant and S4 Sedan, 2007-2008 RS4 Sedan, 2004 RS4 Cabriolet, 2007-2009 A4 Cabriolet and S4 Cabriolet, 2005-2011 A6 Sedan, 2006-2011 A6 Avant, and 2007-2011 S6 Sedan vehicles. These vehicles are equipped with certain air bag inflators assembled as part of the passenger frontal air bag modules used as original equipment or replacement equipment. In the event of a crash necessitating deployment of the passenger frontal air bag, these inflators may explode due to propellant degradation occurring after long-term exposure to absolute humidity and temperature cycling.

Campaign #18V42700022/06/2018

AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE

Volkswagen Group of America, Inc. (Volkswagen) is recalling certain 2009 Audi A4 Cabriolet, S4 Cabriolet, A6 Avant, A6 Sedan and S6 Sedan vehicles originally sold, or ever registered, in Arizona, Arkansas, Delaware, the District of Columbia, Illinois, Indiana, Kansas, Kentucky, Maryland, Missouri, Nebraska, Nevada, New Jersey, New Mexico, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, and West Virginia, or "Zone B." Additionally, unless included in "Zone B" above, Volkswagen is recalling certain 2005-2008 Audi A4 Avant, A4 Sedan, A6 Sedan, S4 Avant and S4 Sedan vehicles, 2007-2008 A4 Cabriolet, RS4 Sedan, S4 Cabriolet and S6 Sedan vehicles, and 2006-2008 A6 Avant and 2008 RS4 Cabriolet vehicles originally sold, or ever registered, in Alaska, Colorado, Connecticut, Idaho, Iowa, Maine, Massachusetts, Michigan, Minnesota, Montana, New Hampshire, New York, North Dakota, Oregon, Rhode Island, South Dakota, Utah, Vermont, Washington, Wisconsin, and Wyoming. These vehicles are equipped with certain air bag inflators assembled as part of the passenger frontal air bag modules used as original equipment or replacement equipment. In the event of a crash necessitating deployment of the front air bags, these inflators may rupture due to propellant degradation occurring after long-term exposure to absolute humidity and temperature cycling.

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Frequently Asked Questions

What are the most common Audi A4 problems?

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2006 Audi A4 has 4 documented issues. The most frequently reported are: Broken Crank Sensor Harness Behind the Bellhousing Mimics a Dead Sensor, 2005-2007 A4 2.0TFSI Cam-Follower / HPFP Diagnosis - TSB 2013147/12, 2002-2006 A4 Factory-CVT Settlement History - Component-Specific Diagnosis. Of these, 3 are rated critical and should be addressed promptly.

Is the Audi A4 reliable?

The 2006 Audi A4 has 4 known issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports. 3 issues are rated critical: Broken Crank Sensor Harness Behind the Bellhousing Mimics a Dead Sensor and 2005-2007 A4 2.0TFSI Cam-Follower / HPFP Diagnosis - TSB 2013147/12 and 2002-2006 A4 Factory-CVT Settlement History - Component-Specific Diagnosis. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common Audi A4 problems?

Repair costs for known Audi A4 issues range from $100 to $1,800, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Broken Crank Sensor Harness Behind the Bellhousing Mimics a Dead Sensor, typically costs $100-$400 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What is the 2002-2008 Audi A4 Broken Crank Sensor Harness Behind the Bellhousing Mimics a Dead Sensor?

B6/B7 A4 owners who set P0322 almost always buy an engine speed sensor (G28) first, and a share of them are back on the forums a week later with the same code and the same no-start. The reason is that on this platform the failure is often the circuit rather than the pickup. The G… Repairs typically run $100-$400. Severity: high.

What is the 2005-2007 Audi A4 2005-2007 A4 2.0TFSI Cam-Follower / HPFP Diagnosis - TSB 2013147/12?

Audi TSB 2013147/12 applies to 2005-2006 A4 vehicles with the BPG engine and 2007 A4 vehicles with the BWT engine when the MIL is on and P2293 is stored; P0087 or P1093 may accompany it. Audi’s procedure checks fuel pressure and wear at the cam follower, intake camshaft lobe and… Severity: high.

Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.

Data compiled from NHTSA recalls, manufacturer TSBs, automotive forums, and AI-assisted research. No aggregated owner-report counts available for this vehicle yet.

  • FAQ
    • Campaign #17V03200011/01/2017

    AIR BAGS:FRONTAL:PASSENGER SIDE:INFLATOR MODULE

    Volkswagen Group of America, Inc. (Volkswagen) is recalling certain model year 2004-2008 Audi A4, and 2005-2011 Audi A6 vehicles originally sold, or ever registered, in Alabama, California, Florida, Georgia, Hawaii, Louisiana, Mississippi, South Carolina, Texas, Puerto Rico, American Samoa, Guam, the Northern Mariana Islands (Saipan), and the U.S. Virgin Islands, or "Zone A." Additionally, unless included in "Zone A" above, Volkswagen is recalling certain model year 2004-2008 Audi A4, and 2005-2008 Audi A6 vehicles originally sold, or ever registered, in Arizona, Arkansas, Delaware, District of Columbia, Illinois, Indiana, Kansas, Kentucky, Maryland, Missouri, Nebraska, Nevada, New Jersey, New Mexico, North Carolina, Ohio, Oklahoma, Pennsylvania, Tennessee, Virginia, and West Virginia, or "Zone B." Lastly, unless included in "Zone A" or "Zone B" above, Volkswagen is recalling model year 2004 Audi A4 vehicles originally sold, or registered, in Alaska, Colorado, Connecticut, Idaho, Iowa, Maine, Massachusetts, Michigan, Minnesota, Montana, New Hampshire, New York, North Dakota, Oregon, Rhode Island, South Dakota, Utah, Vermont, Washington, Wisconsin, and Wyoming. These vehicles are equipped with certain air bag inflators assembled as part of the passenger frontal air bag modules, and used as original equipment or replacement equipment. In the event of a crash necessitating deployment of the front air bags, these inflators may rupture due to propellant degradation occurring after long-term exposure to absolute humidity and temperature cycling.

    Campaign #16V38200001/06/2016

    ENGINE AND ENGINE COOLING:ENGINE

    The Gates Corporation (Gates) is recalling certain aftermarket Tru-Flow Water Pumps, part number TFW 41127, sold at certain NAPA Auto Parts and/or installed by automotive service technicians after November 1, 2013 (and manufactured August 2013 through October 2013) that have a black-colored pulley/sprocket or do not have 'US9377' stamped on the water pump housing. These service replacement parts were sold for use in model year 1999-2005 Audi A4, 2000-2006 Audi TT, 1998-2005 Volkswagen Beetle, 1999-2006 Golf, 1999-2008 and 2011-2013 Volkswagen Jetta, and 2000-2005 Volkswagen Passat. In the affected water pumps, the pulley or sprocket that turns the timing belt may develop microfractures causing the timing belt to fail.

    Campaign #14E00700007/03/2014

    AIR BAGS

    Volkswagen Group of America, Inc. (VW) is recalling certain model year 2008-2009 Audi A4, A5, and Q5 vehicles. In the affected vehicles, the air bag control units may corrode and fail.

    Campaign #16V37600027/05/2016

    + 1 more recalls. Check all on NHTSA.gov

    Enter your VIN at NHTSA.gov to check recalls specific to your vehicle.

    What is the 2002-2006 Audi A4 2002-2006 A4 Factory-CVT Settlement History - Component-Specific Diagnosis?

    The 2013 settlement covered U.S. 2002-2006 A4 vehicles originally equipped with a factory-installed CVT. It used component-specific branches: TCM for 2003-2006; valve body for 2003-2004; and transmission without valve body/TCM for 2002-2004, subject to maintenance proof. Plaintif… Severity: high.

    What is the 2002-2008 Audi A4 B6/B7 Front Suspension Control Arm and Tie-Rod Wear Causing Clunks, Vibration, and Uneven Tire Wear?

    The multi-link front suspension used on B6/B7 A4 models is well known for premature wear of upper and lower control arm bushings/ball joints and, in many cases, outer tie-rod ends. Owners commonly report front-end clunking over bumps, looseness in steering, shimmy at highway spee… Repairs typically run $700-$1,800. Severity: medium.