LCM Alert Validation

Confidence

Failure Category

No Fault Found

Subcategory

No Fault Found

Sensor Verdict: The LCM system generated an alert on the RED (Brake) circuit for trailer V568439 at site DTW1. Based on the vendor's findings and the TechAssist app verification screenshot provided (IMG_1040.png), all five circuits — including Red — were marked as 'Verified' with 'No defects' noted. This suggests the sensor alert may have been a transient fault, a nuisance alert, or a condition that resolved prior to inspection. Confidence in the 'Inconclusive' determination is moderate (42%) because while the app shows green verification, the photographic documentation does not fully substantiate a thorough physical inspection of all RED circuit brake lights.

Photo Evidence: The photos provided show the rear of the Amazon trailer (V568439, AZNG), Indiana license plate P893221, amber side marker lights illuminated (IMGs 1031, 1032, 1034, 1027, 1026), red stop/tail lights that appear illuminated (IMGs 1033, 1036), the rear door area (IMGs 1029, 1037), the nosebox wiring (IMG_1038), a clearance/marker light area (IMG_1030, 1028), and the TechAssist app screenshot (IMG_1040). The red lights visible in photos 1033 and 1036 appear to be functioning LED units. However, not all RED circuit brake lights are individually photographed while illuminated as required by procedure — for example, there is no clear, dedicated photo of the driver-side and passenger-side brake/stop lights simultaneously illuminated from the rear. The nosebox wiring photo (IMG_1038) is present but shows a somewhat disorganized wiring junction box; no obvious loose connections or corrosion are immediately visible, though the image quality and angle make thorough assessment difficult. The TechAssist screenshot confirms all circuits verified, which is a positive indicator.

Vendor Compliance: The vendor partially followed the LCM troubleshooting procedure. Positives include: use of the TechAssist app, provision of a TechAssist completion screenshot showing all five circuits verified green, and a nosebox photo. However, compliance gaps exist: not every RED circuit light is individually photographed while illuminated; the technician's written notes are brief and do not reference a specific feedback category from the required list (e.g., 'no defect found - confirmed with PCT'); and there is no mention of systematically cycling through each lamp position on the RED circuit. The notes state 'ALL VOLTAGES GOOD AND ALL NUTS IN SMART7 TIGHT' which addresses Smart7 integrity but lacks the granular per-light documentation expected.

Repair Summary: No repairs were made to the RED (brake) circuit or any lighting component. The line items billed include a PCT Sensor Activation charge, standard service labor (0.1 hr at $109.90), a shop supply/environmental fee ($3.05), and lot service hourly labor (0.5 hr at $75.00). The sensor activation charge suggests the primary billable action was activating or re-pairing the LCM sensor rather than repairing a physical lighting defect. No parts were replaced, no compliant brand assessment is applicable, and the alerting RED circuit was not repaired because no fault was found.

Key Concerns: Several concerns warrant attention. First, the primary line item billed is a 'PCT Sensor Activation' — this is unusual for a lighting WO and may indicate the sensor was offline or needed re-pairing, which could itself explain the original alert (i.e., the sensor losing connectivity rather than a true lamp failure). This is an important distinction that should be clarified. Second, the photographic evidence does not fully meet procedural standards — dedicated illuminated photos of each RED circuit lamp are missing. Third, the technician's notes lack the structured feedback required by the LCM troubleshooting SOP. Fourth, the nosebox wiring photo shows a complex wiring arrangement that deserves closer scrutiny given the circuit alert history. Fleet maintenance reviewers should consider whether the sensor activation resolved the alert, and if so, whether the root cause (sensor connectivity loss) has been properly documented as the failure mode rather than 'no defect found.'