LCM Alert Validation

Confidence

Failure Category

Lighting

Subcategory

light failure

Sensor Verdict: The LCM sensor alert on the BLACK circuit (Clearance/License Plate) is confirmed as a true positive with high confidence (92%). The technician found the rear top center clearance light non-functional with power present at the socket, confirming the lamp itself had failed. This is a textbook scenario where the LCM correctly identified reduced or absent current draw on the black circuit due to a blown LED lamp. The evidence strongly supports the sensor's alert.

Photo Evidence: The provided photos offer a reasonably complete documentation package. Photos IMG_3256.jpeg and IMG_3257.jpeg show amber/orange mid-trailer side marker lights illuminated on both sides of the trailer — these appear functional and lit. Photos IMG_3252.jpeg, IMG_3253.jpeg, IMG_3254.jpeg, IMG_3255.jpeg show the rear tail/brake lights illuminated in red, confirming those circuits are active. IMG_3251.jpeg captures the Indiana license plate (PD64025) with the license plate light visible but it is not clearly shown as illuminated. IMG_3267.jpeg and IMG_3265.jpeg show the ABS indicator lamp (amber) and a small red marker light at the rear corner mount, with the amber ABS light appearing lit — consistent with the ABS fault noted. IMG_3270.jpeg shows the nosebox interior with multiple wires, though the image quality and wire routing make it difficult to definitively assess condition. Critically, photos of the specific failed/replaced rear top center clearance light — both in its failed state and after replacement — are not clearly present in the set, which is a minor documentation gap. The TechAssist app screenshots (IMG_3278.png showing 'Not Verified' before and IMG_3279.png showing all five circuits 'Verified' after) are present and complete, which is a significant positive.

Vendor Compliance: The vendor (TA) demonstrated generally good compliance with the LCM troubleshooting procedure. The TechAssist app was clearly used — screenshots show the before state (all circuits 'Not Verified,' no data) and the after state (all five circuits — Red, Green, Yellow, Brown, Black — marked 'Verified' with no defects). The nosebox was photographed (IMG_3270.jpeg) and inspected, with the technician confirming all wires tight and correct voltage. The technician also ran a full IPA Trailer ABS diagnostic (IMG_3266.jpeg and IMG_3271.jpeg) addressing the secondary ABS concern. The Gateway Details screen (IMG_3276.jpeg) confirms the sensor is connected to HV2200175 with 12.903V main power. However, the Brown/Marker Power reading of only 0.149V on the gateway screen is worth noting, as it suggests the marker circuit may not have been energized during that specific scan. The technician's written notes are detailed and confirm the methodology. One gap is that not all individual lights are shown clearly illuminated in photos, particularly the replaced clearance light post-repair.

Repair Summary: The primary repair was the replacement of the rear top center clearance light (LED marker lamp, part 33250R Mini LED Marker Red, $23.99) with associated R&R labor. This directly addresses the BLACK circuit alert. Additionally, an ABS diagnostic was performed — codes for 'No Speed' on YE1 and YE2 sensors were found, wheels were spun to clear the codes, and the ABS light self-corrected. A PCT sensor activation line item was also included, suggesting Smart Trailer sensor work was performed alongside the lighting repair. All five TechAssist light circuits were verified as passing post-repair (IMG_3279.png). The LED part used (red mini LED marker) appears appropriate for a clearance/marker lamp replacement.

Key Concerns: There are a few items worth flagging. First, the Brown/Marker Power voltage reading of 0.149V on the Smart Trailer gateway screen (IMG_3276.jpeg) is extremely low and may indicate the marker circuit was not powered during that reading — this should be monitored. Second, the ATIS Lamp sensor shows 'Not Connected / Unverified' on the gateway screen, which is a separate Smart Trailer sensor issue that was not explicitly addressed in the repair notes. Third, the ABS active faults (YE1 and YE2 'No Speed') shown in IMG_3266.jpeg were resolved by spinning the wheels, but the follow-up scan in IMG_3271.jpeg shows zero active and stored faults, which is acceptable — however, this was a transient fault and should be watched for recurrence. The line item for 'PCT Sensor Activation' is present but not explained in the technician notes, which may warrant clarification from the vendor. Overall, the core repair is sound and the LCM alert was valid.