Camera-Only AEB Disable After Windshield Replacement
A 2021 sedan arrives at your shop with a stone-chip crack running 240 mm across the forward camera's field of view. The customer wants an aftermarket windshield because the OEM glass is on backorder for three weeks. The vehicle uses a single forward monocular camera behind the mirror for automatic emergency braking (AEB), lane keeping, and traffic sign recognition; there is no separate radar unit for AEB. The aftermarket glass is listed as 'camera bracket compatible,' but the bracket mounting surface tolerance is not specified, and the glass has no optical-grade clear zone documentation. After installation, the dash shows 'Forward Camera Temporarily Unavailable' and AEB, LKA, and adaptive high beam are all inhibited. The customer is scheduled to drive 600 km on a highway tomorrow.
1. Should you release the vehicle with the aftermarket glass as-is? Lay out the decision and the reasoning.
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No. Release is not appropriate with AEB/LKA inhibited for a 600 km highway trip.
Reasoning chain:
- Safety function dependency. On this vehicle, AEB, LKA, and adaptive high beam all depend on the single forward camera. With the camera unavailable, the driver loses the primary crash-avoidance function, and the vehicle is not in the condition the customer believes it is.
- Glass is part of the sensor path. The camera images through the windshield. Optical distortion, wedge angle, bracket surface flatness, and the clear/black-out zone geometry are all part of the sensor's optical design. 'Bracket compatible' only addresses mechanical fit, not optical or aiming performance.
- No documented optical spec = no basis to calibrate. Without a clear-zone spec and bracket flatness tolerance, you cannot demonstrate the camera can be aimed and calibrated within the manufacturer's window. A calibration that 'passes' on bad glass is not evidence of correct performance.
- Customer communication and options. Explain the trade-off honestly: OEM glass plus calibration is the path that restores AEB. Offer to keep the vehicle, order OEM glass, and provide a loaner or rental; do not let the customer drive away believing the systems will 'sort themselves out.'
- Documentation. Note on the RO that the vehicle was retained because a safety function was inoperable and the aftermarket glass lacked optical documentation.
2. The customer insists on taking the car and says 'the warning light is just a nuisance.' How do you handle the handoff, and what do you document?
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You cannot physically stop an adult customer from driving their own car, but you can make the risk explicit and documented.
- Explain in plain terms: 'Your car's automatic emergency braking and lane keeping are switched off right now because the camera can't see properly through this glass. Those are the systems that brake for you if you don't react in time.'
- Offer alternatives first: OEM glass with calibration, a loaner, or a rental. Make the safe option the easy option.
- If they still decline: have them sign a written acknowledgment that (a) AEB, LKA, and adaptive high beam are inoperative, (b) the shop recommended OEM glass and calibration, and (c) the customer declined. Give them a copy.
- RO documentation: record the DTCs, the inhibit status, the recommendation, the declined recommendation, and the signed acknowledgment. Note the date, time, and who spoke to whom.
- Do not clear codes or 'make the light go away' to appease the customer. Clearing a DTC does not restore function and destroys diagnostic evidence.
- Follow-up: contact the customer after the trip to schedule the OEM glass and calibration.
3. The shop later installs OEM glass. What must be true before you sign off on the calibration?
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Sign-off requires more than 'the light went out.'
- Pre-conditions: correct OEM glass installed per procedure, camera bracket seated and torqued to spec, no debris or fingerprints on the lens or glass, tire pressures correct, fuel level within the procedure's range, vehicle on a level surface, and any required targets positioned to the manufacturer's dimensions.
- Environment: lighting, floor markings, and target distance per procedure; no reflective surfaces or moving objects in the camera's view.
- Calibration result: the scan tool reports a successful calibration, and the DTCs for camera aiming are cleared only after success.
- Post-checks: verify AEB, LKA, and adaptive high beam are enabled (not inhibited), perform a road test per the procedure, and confirm no new DTCs return.
- Documentation: record the calibration type (static/dynamic), target positions, ambient conditions, scan tool report, and road-test result on the RO. If any pre-condition could not be met, do not sign off.