LCM Alert Validation

Confidence

Failure Category

No Fault Found

Subcategory

no defect found (confirmed with PCT)

Sensor Verdict: The LCM alert flagged the BLACK circuit (Clearance / License Plate) on trailer WV2500773. Based on the available evidence, the final determination is No Defect Detected at the time of inspection, with moderate confidence (55%). The PCT TechAssist app screenshot confirms all five circuits — including the BLACK circuit — were verified as operational by the time the work order was completed. However, the heavily corroded nosebox presents a plausible explanation for an intermittent fault that may have cleared before or during the technician's visit, leaving some uncertainty about whether a real transient defect existed.

Photo Evidence: The photo set is reasonably comprehensive but not fully complete for the BLACK circuit specifically. Photos 8 and 13 show amber/orange side marker lights illuminated and operational. Photos 4 and 6 show small red clearance/marker lights illuminated at the front corner and lower body. Photo 17 shows red clearance lights at the rear roofline illuminated. Photo 15 shows the license plate light (LED, white) appearing to be lit. Photo 20 (PCT Sensor Details screenshot) confirms all five circuits verified. Photos 3 and 16 show the nosebox interior, which exhibits severe corrosion, blackening of wire insulation, oxidation on terminal studs, and general degradation — this is a notable finding. The Job Summary screenshot (Photo 1) confirms Light Circuit verified. However, dedicated close-up photos of each BLACK circuit light (license plate lamp and clearance lights) individually illuminated are not fully provided, making it difficult to confirm 100% of the BLACK circuit lamps were tested.

Vendor Compliance: The vendor used the PCT TechAssist app and obtained verified status on all five circuits, which is the primary compliance requirement. The technician notes reference performing a full light check and verifying all circuits in the PCT app. The Job Summary screen (Photo 1) confirms Light Circuit verified with a green checkmark. The nosebox was photographed (Photos 3 and 16), satisfying that documentation requirement. However, the vendor did not photograph every individual light in the BLACK circuit illuminated in isolation, which partially undermines documentation completeness. The feedback provided aligns with the 'no defect found (confirmed with PCT)' category from the expected list.

Repair Summary: No repairs were made to address the alerting BLACK circuit. The line items consist of indirect labor charges, a PCT sensor activation fee, standard service labor (0.1 hr at $109.90), shop supply fee ($3.05), and lot service hourly labor (0.5 hr at $75.00). None of the line items indicate replacement of a license plate lamp, clearance light, wiring, or nosebox components. The absence of parts replacement is consistent with the no-fault-found determination. The corrosion observed in the nosebox was not addressed, which is a missed opportunity for preventive maintenance.

Key Concerns: The most significant concern is the heavily corroded nosebox (Photos 3 and 16), which shows blackened wire insulation, oxidized terminals, and what appears to be moisture intrusion. This level of corrosion is a known cause of intermittent LCM false positives and could trigger repeat alerts in the near future. The vendor did not flag or repair this condition despite it being clearly visible and photographed. Additionally, the ATIS Lamp sensor is shown as 'Not Connected / Unverified' in Photo 19, which is a separate concern not addressed in this work order. The mismatch between the severity of nosebox corrosion and the lack of any corrective action is a key gap. Fleet management should consider scheduling a nosebox cleaning/repair to prevent recurrence of LCM alerts on this trailer.