Advanced Driver Assistance Systems (ADAS) are now present on nearly every late-model vehicle, yet calibration requirements remain one of the most misunderstood areas.

At ADAS Depot, we regularly work with shops that are either entering the ADAS space or refining existing calibration workflows. The following questions reflect the most common technical and procedural issues we get asked in real-world shop environments. These answers are based on OEM service information, industry best practices, and hands-on calibration experience. Please note: OEM instructions should always take precedence over scan tool prompts.

“When is a calibration required?”

Almost any repair that disturbs an ADAS sensor or its mounting location requires calibration, as defined by OEM service information.

The most common triggers:

Windshield cameras

• Windshield replacement
  
  
• Camera bracket replacement
  
  
• Camera R&I (Replace and Install)
  
  
• Dash removal
  
  
• Airbag deployment
  
  
• Roof repairs on some OEMs
  
  

Front radar

• Bumper removal
  
  
• Grille replacement
  
  
• Radar bracket replacement
  
  
• Collision damage (even light)
  
  
• Alignment that significantly changes thrust angle
  
  
• Ride height changes
  
  

Blind spot radars

• Rear bumper removal
  
  
• Corner repairs
  
  
• Quarter panel replacement
  
  
• Inner bumper support changes
  
  
• Wheel offsets/ride height changes on some models
  
  

Surround view / bird’s-eye cameras

• Mirror replacement
  
  
• Door removal
  
  
• Trunk lid removal
  
  
• Front or rear camera changes
  
  
• Wheel/tire size changes
  
  

Parking sensors

• Sensor replacement
  
  
• Bumper cover replacement
  
  
• Bracket adjustment
  
  

In practice:
If the OEM mentions calibration in the FSM, you must do it. If the system uses a camera or radar, calibration is typically required.

“Why won’t my calibration complete?”

A common refrain in the industry is “calibration is the final 5% of the job, but it requires 100% of the prep work.” The vast majority of calibration failures boil down to preconditions not met.

Common contributing factors include:

• Floor slope > 1° (some OEMs require <0.5°)
  
  
• Vehicle not at correct ride height
  
  
• Alignment out of spec
  
  
• Steering angle sensor not initialized
  
  
• Poor lighting / shadows on camera targets
  
  
• Target placed at wrong distance
  
  
• Crooked calibration frame
  
  
• Uneven tire pressure
  
  
• Vehicle not loaded per OEM (fuel level, empty trunk, driver weight, etc.)
  
  

For radar:

• Radar bracket bent a few millimeters
  
  
• Fascia aftermarket / repainted and blocking radar
  
  
• Radar tilted vertically because bumper not clipped properly
  
  

For dynamic calibrations:

• Poor lane markings
  
  
• Heavy traffic
  
  
• Speed not met (many require 45+ mph for several minutes)
  
  

The majority of calibration failures are caused by physical setup issues rather than scan tool limitations.

“Do I need a perfectly level floor for ADAS calibrations?”

Mostly yes, but “perfectly” depends on OEM:

OEM	Floor Requirement
Honda	< 1° slope; ideally < 0.5°
Toyota	“Level surface” (practically < 0.5°)
Subaru	Very sensitive — < 0.5° advised
Hyundai/Kia	Often allow slight slope; Autel compensates, OEM does not
VW/Audi	Strict; < 0.5°
GM	Less sensitive but still requires < 1°

Can aftermarket systems compensate?

• Autel: Yes, uses laser leveling + software compensation. Still needs reasonably flat floors (< 1°).
  
  
• Topdon & Launch: Some compensation; less sophisticated.
  
  
• OEM targets: Almost always require the surface itself to be level.
  
  

Can you shim (i.e. put a piece of plastic or wood beneath) the vehicle?

Technically yes, but never recommended unless OEM explicitly allows. You are changing the suspension geometry. The car is no longer sitting at its natural "curb height."

“Is a post-scan + test drive enough?”

No. A system that appears to work can still be misaligned by several degrees, enough to cause:

• Lane departure inputs too early or too late
  
  
• ACC following distance errors
  
  
• Blind spot false negatives
  
  

Only an OEM-approved calibration resets the sensor to known geometry.
Functionality does not mean accuracy.

“Why do OEM service instructions contradict my aftermarket scan tool?”

Common reasons:

1. OEM updated their procedures; aftermarket hasn’t caught up.

Autel is usually fast, but still lags 3–12 months behind some models.

2. Aftermarket tools sometimes add a static calibration even when OEM uses dynamic-only.

They do this to cover variations across global markets.

3. Sometimes the aftermarket tool simply mislabels the procedure.

Example: some Autel menus say “Static + Dynamic” but the static step simply verifies sensor initialization.

Always follow OEM instructions over the scan tool.

 

“How accurate does target placement need to be?”

Modern ADAS targets are extremely sensitive, especially for camera-based systems.

Typical tolerances:

• ±2 mm target center
  
  
• ±1 mm on height
  
  
• ±0.5° yaw / pitch
  
  
• ±3 mm front-to-back distance
  
  
• ±2 mm left/right offset
  
  

Even being 5 mm off can cause:

• Pulling during lane keep
  
  
• Early/late lane departure warnings
  
  
• Poor road sign detection
  
  
• Reduced ACC distance accuracy
  
  

Laser measurement is preferred for anything camera-based.

 

“What’s the correct test drive procedure?”

Varies by OEM, but the typical requirements:

Speed

• 25–45 mph minimum
  
  
• Some require >55 mph (Subaru, Mazda radar)
  
  
• Toyota often needs several miles at >35 mph
  
  

Lane Markings

• Clean, continuous white/yellow
  
  
• No construction zones
  
  
• No heavy shadows
  
  
• No rain or low sun glare
  
  

Traffic

• Light to moderate
  
  
• Enough vehicles for ACC to lock onto
  
  

Duration

• 5–20 minutes depending on system
  
  
• Some require two separate conditions (straight road + curves)
  
  

If lane lines are poor, the dynamic calibration may never complete.

 

“Can aftermarket scan tools be trusted for ADAS?”

Autel

 

• Widest coverage
• Mimics OEM procedures closely
• Widely used in professional environments
• Commonly relied upon by calibration-focused shops

 

Launch / Topdon / XTool

• Good as secondary systems
  
  
• Inexpensive
  
  
• Strength is convenience, not OEM-level precision
  
  
• Radar alignment less reliable
  
  
• Camera target detection less consistent
  
  

Texa

• Excellent for Euro cars
  
  
• Very OEM-like processes
  
  
• Limited US tech penetration
  
  

General rule:
Autel or Texa for professional shops; others for convenience or light-duty work.

 

“Does ride height really matter?”

Yes, dramatically.

Even 1/4 inch difference at the suspension can:

• Tilt the radar several degrees
  
  
• Change camera pitch
  
  
• Move blind spot sensors off axis
  
  

Examples:

• Honda: if ride height out of spec, radar cannot be calibrated
  
  
• Toyota: camera calibration will pass but lane keep will pull
  
  
• Subaru: extremely sensitive to pitch angle
  
  
• GM trucks: lifts require radar bracket shimming or new brackets
  
  

If the car is lowered or lifted, you need to document, and OEM calibration may not succeed.

 

“Am I liable if I skip a required calibration?”

Yes.
Courts treat ADAS sensors like airbags, safety systems.

If:

• The car needed calibration
  
  
• The shop knew it
  
  
• The shop skipped it
  
  
• A safety failure occurred
  
  

Shops may be exposed to liability depending on jurisdiction and circumstances.

 

Best practice:

• Provide the customer a written statement
  
  
• Get signature if customer refuses calibration
  
  
• Document scan results
  
  
• Store before/after images of target setup
  
  

ADAS is legally treated as a safety-critical system.

 

“Why do OEMs require expensive targets when aftermarket works?”

Among the reasons:

1. Exact reflectivity of printed patterns
   
   
2. Exact distortion control
   
   
3. Exact pixel dimensions
   
   
4. Exact contrast ratio
   
   
5. Aftermarket prints warp over time
   
   
6. Aftermarket targets may not match regional variations (Japan/Europe vs US patterns)
   
   

Autel’s algorithm compensates for imperfections, but OEMs don’t allow compensation.

 

“How do I verify a calibration actually worked?”

Here, best practices include:

1. Confirm no DTCs

Before + after.

2. Verify sensor alignment values

Many OEMs show:

• Horizontal angle
  
  
• Vertical angle
  
  
• Yaw/pitch misalignment
  
  
• Camera focal calibration score
  
  

3. Road test

• Lane keep
  
  
• Lane departure
  
  
• ACC following distances
  
  
• Blind spot performance
  
  
• Sign recognition if equipped
  
  

4. Documentation

• Screenshots
  
  
• Measurement photos
  
  
• Final printed calibration report
  
  
• Pre/post-scan documentation
  
  

5. Customer demonstration (optional)

Shops are starting to do this to avoid false claims. 

 

You can read our insurance guide about the importance of showing documentation. 

 

“Can I calibrate outside? What about sunlight?”

Static calibrations:

Usually no.

Reasons include:

• Sun glare on camera
  
  
• Shadows distort target contrast
  
  
• Wind can move boards
  
  
• Uneven ground
  
  
• Reflective surfaces confuse radar
  
  

If you must calibrate outside:

• Use shade
  
  
• Avoid direct midday sun
  
  
• Ensure perfectly flat concrete
  
  
• Avoid changing light conditions
  
  

Dynamic calibrations:

Outside is required, but:

• Need clear lane lines
  
  
• Avoid low sun angle
  
  
• Avoid nighttime unless OEM allows
  
  

We hope these FAQs set you on the right path for ADAS calibrations. Any questions, please reach out to us at 925-566-8545 or sales@adasdepot.com.

 

Darren.