Prevention FAQ — FMCSR 393.62C: Windshield Wipers

Inspectors perform a functional test: both wipers must operate across their full sweep and return to the park position. They check for missing wiper arms, non-functional blades, and disconnected linkages. Our inspection records show this violation is cited most heavily in Texas, where 9 citations occurred in the last 180 days with a 55.6% out-of-service rate—higher than the national average of 31.4%. Inspectors will activate wipers in both low and high speed. Missing wipers or arms that do not move across the windshield result in immediate citation. Even partial inoperability (one wiper functioning, one not) triggers the violation. Pay particular attention if your fleet operates in Texas or Illinois, where enforcement intensity is highest.

Add these four steps to your driver pre-trip protocol:

1. Visual inspection: Confirm both wiper arms are present and seated on the windshield.
2. Blade condition: Check for cracking, streaking, or separation from the arm.
3. Functional test: Activate both speeds (low and high) before entering traffic. Both wipers must complete a full sweep.
4. Park position: Confirm wipers return fully to the park position at the base of the windshield.

Drivers should perform this check with the ignition on but the engine off. If either wiper fails to move, does not complete a full sweep, or makes noise, the vehicle must be taken out of service until repaired. Document the check on your daily vehicle inspection report (DVIR) with a date and driver signature.

Maintain a wiper maintenance log for each vehicle that includes: date of repair, parts replaced (wiper blades, arms, motor, or linkage), cost, technician name, vehicle mileage, and date returned to service. Retain receipts or work orders from repair facilities for a minimum of one year. Your DVIR records showing pre-trip wiper checks create a preventive maintenance trail and demonstrate due diligence if a citation occurs. If placed out-of-service (which happened in 81.8% of our recorded cases), document the inspection citation number, the corrective action taken, and the reinspection result. This documentation supports any DataQs challenge and proves your fleet's commitment to compliance.

Our co-occurrence data reveals three systemic patterns:

Inspection and maintenance gaps: 393.62C appears alongside 396.3A1 (inspection/repair/maintenance of parts) in 2 of the last 90 days' inspections. This suggests missing or inadequate pre-trip reviews before vehicles enter service.

Broader steering and brake issues: Co-occurrence with 393.53B (steering system wear) and 393.47E (slack adjuster defects) in 2 shared inspections each indicates that some citations occur during comprehensive safety audits. If wipers are missed, other critical systems may be overlooked too.

Lighting and visibility clusters: Pairing with 393.60C (window obstructions) and inoperable lamp codes suggests visibility-system defects occur in waves. Root-cause analysis should examine your preventive maintenance intervals and whether technicians are systematically checking all visibility-related items together.

After wiper repair, use this three-step verification process:

1. Initial functional test: Technician activates both speeds on level ground with ignition on. Both wipers must sweep fully across the windshield and return to park. Test multiple times to confirm consistency.
2. Road test: Driver takes vehicle on a short 5-minute circuit in dry conditions and activates wipers at both speeds. Listen for grinding, squeaking, or stuttering that suggests linkage or motor issues.
3. Documentation: Repair technician signs off with date, time, vehicle mileage, parts replaced, and confirmation that both wipers operated correctly. Driver and fleet manager co-sign the work order.

Do not return the vehicle to revenue service until all three steps are complete and documented. This prevents repeat citations and reduces your vulnerability to out-of-service placement.

Within 48 hours of a 393.62C citation, conduct a root-cause review:

1. Driver interview: Ask when the wiper malfunction began, whether it was flagged in a pre-trip check, and why it wasn't reported before the roadside inspection.
2. Vehicle history: Pull maintenance records for the past 90 days. Check if wipers were serviced, and if so, why the repair failed.
3. Fleet-wide audit: Inspect all vehicles of the same make and year for similar wiper issues. Our data shows VOLV vehicles account for 8 citations—the highest among makes cited. If you operate Volvo vehicles, check wiper motor and linkage for a design pattern.
4. Inspection protocol review: Ensure all drivers completed pre-trip checklists and that DVIR logs captured wiper status before the citation date.
5. Corrective action: Retrain the cited driver on pre-trip wipers, adjust your PM interval if needed, and file a DataQs challenge if the citation was issued in error.

FMCSR 393.62C carries a CSA severity weight of 4 and ranks #1763 out of 3,036 FMCSR codes by citation volume. While not among the highest-volume violations, the 81.8% out-of-service rate is significantly higher than the all-FMCSR average of 31.4%, which means citations are more likely to result in vehicle removal from service. Each citation contributes to your Vehicle Maintenance BASIC score. A single citation has modest impact; however, patterns of out-of-service placement draw regulatory scrutiny and trigger CSA alerts. If your fleet accumulates multiple 393.62C violations within a 12-month window, it signals to auditors that your preventive maintenance program is weak and may prompt an FMCSA roadside safety audit or carrier safety audit.

Structure wiper-focused training around three topics:

1. Pre-trip fundamentals: Teach drivers that windshield wipers are critical for safe operation, not optional. A driver cannot safely operate a vehicle in rain or snow without functioning wipers. Emphasize that visibility defects are among the first things inspectors check.
2. When to report: Train drivers to report wiper malfunction immediately to dispatch or a supervisor—not to attempt a roadside fix or ignore the issue. Timely reporting prevents citations and keeps the vehicle in compliance.
3. Vehicle-specific quirks: VOLVO buses (8 citations all-time) may have wiper motor or linkage issues specific to that model year. If your fleet operates Volvo units, include model-specific troubleshooting (e.g., how to seat the wiper arm properly, when to replace the linkage vs. blades).

Deliver this training annually and within 30 days of a citation to the driver's unit.

File a DataQs challenge if any of these conditions apply:

1. Documentation mismatch: Your DVIR records show wipers were functional on the day of citation, but the inspector cited them as inoperative. This creates a factual dispute worth challenging.
2. Repair verification: You have a work order and technician sign-off dated the same day or day before the inspection proving wipers were repaired and tested.
3. Inspector error: The citation document does not clearly indicate which wiper (driver or passenger side) or both were cited, or the severity description conflicts with a functional test performed by your technician immediately after.
4. Duplicate citation: Verify the citation date and vehicle. If the same vehicle was cited for wipers on the same date by different officers, one citation may be erroneous.

DataQs challenges require supporting documentation (DVIR, work order, photos of repairs, technician statement). Submit within 90 days of the violation date through the SaferWeb portal.

Establish a monthly self-audit cadence. Our last 90 days of data show 7 citations with a concentration in March 2026 (7 citations, 6 out-of-service). This suggests seasonal or operational clustering. Conduct a full fleet wiper inspection once per month and document the results by vehicle. Additionally, review your DVIRs weekly to identify any driver reports of wiper malfunction and cross-check against your repair logs to confirm timely service.

After each out-of-service wiper citation, perform a follow-up audit on all similar vehicles within 2 weeks. Given the 81.8% out-of-service rate for this code, wipers are frequently the reason vehicles are sidelined, making them a high-priority preventive maintenance item. A monthly audit protects revenue by reducing surprise out-of-service placements and demonstrates to regulators that your fleet actively monitors visibility systems.