LCM Alert Validation

Confidence

Failure Category

Lighting

Subcategory

Lighting - Missing Light

Sensor Verdict: The LCM alert on the RED (Brake) circuit is assessed as a legitimate 'Defect Detected' with moderate-to-high confidence (72%). The technician discovered a missing middle strobe light on the brake circuit, which is a credible cause for the sensor to flag a current anomaly. The remaining brake lights were confirmed operational, but the absence of one lamp in the circuit is sufficient to justify the original alert. The confidence is not higher because the sensor specifically monitors current draw across the full circuit, and the vendor's final PCT verification showed all circuits as 'Verified' — suggesting the missing lamp may not have caused a significant enough current deviation to definitively attribute the alert solely to it, or the circuit topology may allow partial illumination without full current loss.

Photo Evidence: The submitted photos provide a reasonably comprehensive view of the trailer's lighting system. Photos IMG_1002 and IMG_0999 show the rear brake/tail light clusters on both the roadside and curbside, with red LED lights illuminated and appearing functional. IMG_1006 shows the rear light cluster from an overhead angle with lights energized. IMG_1003, IMG_1001, IMG_1007, and IMG_1017 document amber side marker/clearance lights on both sides of the trailer, all appearing illuminated and operational. IMG_1008 shows interior marker lights along the trailer door post, lit in red. IMG_0997 provides a wide rear view showing the full tail light cluster and license plate area. Crucially, IMG_1013 provides a clear photo of the open nosebox with visible wiring harness and terminal connections — this is a key required element. IMG_1015 shows the 7-way connector receptacle, and IMG_1014 shows it covered with a Phillips Sta-Dry cap. IMG_1018 (PNG screenshot) shows the PCT TechAssist app with all five circuits listed as 'Not Verified,' while IMG_1019 shows the same app with all five circuits marked 'Verified' — confirming the full light check was completed. Photo 'image.jpg' shows what appears to be a license plate light or small marker lamp, partially dislodged from its housing with the lens exposed — this may be the missing/displaced strobe light referenced in the technician notes, though it is not definitively identified. No photo specifically documents the missing middle strobe light location or its empty mount, which would have been ideal documentation for this repair finding.

Vendor Compliance: The vendor (TA) demonstrated good overall compliance with the LCM troubleshooting procedure. They connected to the trailer, performed a full light circuit check, photographed lights illuminated across the trailer, captured the nosebox interior, photographed the 7-way connector, and provided before/after PCT TechAssist screenshots (IMG_1018 showing 'Not Verified' and IMG_1019 showing all circuits 'Verified'). The technician also noted checking the nosebox for tight connections and proper power delivery, and inspected the 7-way — all per the prescribed procedure. The failure subcategory reported aligns with the defined expected categories ('light missing'). The main gap in compliance is the absence of a specific photo of the missing light's mounting location or the removed/absent lamp itself, and no photo was taken that unambiguously shows the strobe light in question.

Repair Summary: No repairs were made on this work order. The technician identified the root cause — a missing middle strobe light on the brake circuit — but was unable to replace it because the part was not stocked at the TA location. The vendor noted the part would need to be ordered. The line items confirm no parts were used and no labor charges were billed. The alerting RED circuit was not repaired, meaning the trailer was returned to service with the known defect unresolved. A follow-up work order should be opened to procure and install the correct strobe/marker lamp to bring the trailer into full lighting compliance.

Key Concerns: The primary concern is that the identified defect — a missing middle strobe light — was not repaired, and no follow-up action appears to have been initiated based on the available data. The trailer was released with a confirmed lighting defect on the brake circuit, which is a safety and regulatory compliance issue. Additionally, the 'image.jpg' photo showing a loose/exposed lamp housing is ambiguous and may represent the defective component or an unrelated issue — clearer documentation would be expected. The PCT app screenshots do show all circuits 'Verified,' which is somewhat inconsistent with having a missing light unless the circuit can still pass the current threshold test with the remaining lamps. This warrants clarification on whether the missing strobe is on a separate branch or sub-circuit. No signs of wiring damage, corrosion, or nosebox issues were noted, which is positive. Overall, vendor thoroughness was acceptable, but the inability to complete the repair is the outstanding concern requiring follow-up.