2021-2023 Audi Brake Noise TSB 2034181/19

Symptoms

Owners of affected Audi vehicles, including the Audi e-tron, may experience various brake noises from the front or rear brakes. These noises can be described as a "squeal, squeak, grinding, groaning, thumping, or creaking."

Why Your Audi's Brakes Are Noisy

Technical Service Bulletin (TSB) 2034181/19 identifies several common reasons for brake noise. Understanding these can help diagnose the specific Audi e-tron brake noise you might be hearing.

Potential causes include:

• Wear and tear: Brake discs or pads may be close to or below their wear limit.
• Improper bedding: New brake pads and/or discs might not have been properly embedded after installation.
• Aftermarket components: The use of aftermarket pads or discs can sometimes contribute to noise.
• Debris: Small stones, grit, road salt, or sand can get trapped between the brake disc and brake pad.
• Rust: Discs can develop rust, especially if the vehicle has not been driven for a long period.
• Grooved discs: Brake discs can become grooved over time.
• Chemical contamination: Chemical residue from wheel or tire cleaner sprayed directly onto the brake disc can cause discoloration and noise.
• Pad marks: Material transfer from brake pads to discs can occur if the vehicle is parked for extended periods in wet or snowy conditions.

Important Warnings for Owners

• Do not use this TSB if another brake noise TSB is applicable to your VIN. Always ensure the correct bulletin is being followed for your specific vehicle and issue.
• Warranty coverage: If your vehicle is outside of its warranty period (typically 48 months/50,000 miles), this Technical Service Bulletin is for informational purposes only, and any repairs may not be covered.

Diagnosis and Repair Process Summary

Diagnosing and resolving Audi e-tron brake noise involves a systematic approach by technicians. The process begins with a thorough inspection and may include specialized tools.

1. Initial Inspection: Technicians will first check the overall condition of the brakes against the common causes listed in the technical background. If the noise isn't directly attributable to these causes, further steps are taken.
2. Locate the Noise: Determining the exact location of the brake noise (e.g., left front, rear axle) is crucial. An assistant may be needed to listen from inside or outside the vehicle.
3. Record and Document: Technicians are instructed to obtain a sound or video recording of the noise, preferably using the Audi analysis app (as referenced in TSB 2051095: 46 Audi frequency analysis). A questionnaire must also be filled out, providing detailed information about the conditions under which the noise occurs. Customer-provided recordings are acceptable.
4. Brake Cleaning Procedure: This involves a specific sequence of actions to clean the brake pads and discs:
   • Perform up to five ABS stops from speeds above 50 mph, allowing the brake components to cool for over a minute at speeds greater than 50 mph between each stop.
   • Allow the vehicle to sit for two hours to cool down completely.
   • Conduct a test drive to check if the noise has been eliminated.
5. Technical Assistance: If the noise persists after the cleaning procedure, a Technical Assistance Center (TAC) ticket must be opened. This ticket should include the completed Brakes Acoustic Questionnaire, the sound/video recording (preferably from the Audi frequency app), a screenshot of the frequency analysis showing the peak frequency, and photos of the affected brake discs and pads (Figures 7-11) to clearly show their condition.

Known Brake Noise Frequencies and Suggestions

This TSB provides reference information on specific noise frequencies and corresponding inspection points for different brake systems. Technicians are advised to always review the ELSA Repair Manual and VIN-specific TSBs for the most accurate information.

For ATE-TEVES Brake Systems (PR codes: 1LF, 1LG, 1LL, 1ZK, 1LJ, 1LP):

• 1.6 KHz from front brakes: Inspect the front pads.
• 3.2 KHz / 11 KHz from front brakes: Inspect both front discs and pads.

For TRW Brake Systems (PR codes: 1LA, 1LB, 1LD, 1LT, 1ZT, 1J):

• 1.6 KHz to 1.7 KHz from front brakes: Inspect the front discs.
• 3.2 KHz from front brakes: Inspect, clean, and lubricate the guide pins in the caliper carrier using anti-seize paste G052560A2.
• 7.8 KHz from front brakes: Inspect the front pads.

Required Tools or Parts

• Audi analysis app: Used for recording and analyzing brake noise frequencies.
• Anti-seize paste G052560A2: Specifically recommended for lubricating guide pins in TRW brake systems.

Warranty Information

Warranty claims for this type of repair (Damage Code 0020, Labor Operation 4617 8099) are typically covered for vehicles up to 48 months or 50,000 miles. The labor operation includes cleaning brake pads and discs, road tests, and submitting an audio file and questionnaire. Diagnostic time for GFF and road tests are generally not allowed for reimbursement.

Related Technical Service Bulletins

This TSB may reference or be used in conjunction with other bulletins for a comprehensive diagnosis:

• TSB 2022584: 46 Brake pulsation diagnostic guidelines: For concerns related to brake pulsation.
• TSB 2051095: 46 Audi frequency analysis: Provides guidelines for using the Audi analysis app for noise diagnosis.

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Source: NHTSA ID: 10207121