U0268 on 2018 Chevrolet Traverse: Lost Communication With Side Object Detection Module

What's Unique About the 2018-2018 Chevrolet TRAVERSE

The 2018 Traverse is built on GM's C1XX platform, shared with the Buick Enclave, GMC Acadia, and Cadillac XT5. On these SUVs, the side object detection modules are mounted low in the corners of the rear bumper. This location makes them extremely vulnerable to water, road salt, and debris kicked up by the rear tires, leading to a high rate of failure from corrosion. As a result, a U0268 code on this platform is more likely to be a failed module from water intrusion than a simple wiring issue elsewhere. The module's poor sealing is a known design flaw.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• "Service Side Blind Zone Alert" message on the driver information center
• Blind spot indicator lights in the side mirrors do not illuminate or stay on continuously
• Rear Cross-Traffic Alert system is inoperative when reversing
• Parking assist features may be disabled
• Audible alerts for blinkers, back-up, and other functions may stop working if the failure affects the Active Noise Cancellation (ANC) module

Most Likely Causes

1. Failed Side Object Detection Module (Passenger Side) 🔴 High Probability The module's location in the rear bumper makes it highly susceptible to water and road salt intrusion, which corrodes the internal electronics. The module's own seals can fail, allowing moisture to penetrate the housing.
   How to confirm: After removing the rear bumper cover, visually inspect the module for swelling, cracks, or white/green powder-like corrosion on the housing and connector pins. Water may physically drip out of the connector when it is unplugged.
   Typical fix: Replace the passenger-side Side Object Detection Module and its electrical connector pigtail. The new module must be programmed by a dealer or a qualified shop with GM's SPS2 software.
   Est. part cost: $250-$450
2. Corroded or Damaged Wiring Connector 🟡 Medium Probability The same water intrusion that kills the module also destroys the pins in its 8-pin electrical connector. Road salt accelerates this corrosion.
   How to confirm: Inspect the connector for corroded, bent, or broken pins. Often, the corrosion is obvious (green or white crust). Check for a secure connection; sometimes the connector can become partially unplugged from a minor bumper impact.
   Typical fix: Replace the connector pigtail, which involves cutting the old connector off and splicing the new one wire by wire using heat-shrink butt connectors. This is often done at the same time as module replacement.
   Est. part cost: $40-$90
3. Weak 12V Battery ⚪ Low Probability Modern vehicles with many electronic modules are sensitive to low voltage. An aging battery can cause random communication faults across various systems, including the driver-assist network.
   How to confirm: Test the battery with a professional digital tester. A resting voltage below 12.4V or low cold cranking amps (CCA) under load indicates a weak battery.
   Typical fix: Replace the vehicle's 12V AGM battery.
   Est. part cost: $200-$350

Rare But Worth Checking

• Faulty Diagnostic Tool: GM Technical Service Bulletin #PIT5441C warns that a faulty MDI (Multiple Diagnostic Interface) cable used by a technician can sometimes generate false communication codes, including U0268. This is a problem with the diagnostic equipment, not the vehicle, but can lead to misdiagnosis.
• Faulty Active Safety Control Module: While rare, the main control module that orchestrates the driver-assist systems can fail. One owner on a Reddit forum reported their dealer diagnosed a 'bricked' safety control module that caused numerous driver-assist warnings. This should only be considered after the side module and wiring have been ruled out.

Diagnosis Steps

1. Scan all vehicle modules with a professional-grade scan tool to confirm U0268 is present in the Active Safety Control Module and that the Right Side Object Detection Module is the one not communicating.
2. Check the health of the 12V battery with a load tester to rule out low voltage as a cause.
3. If possible, have a technician check for TSB #PIT5441C to ensure their diagnostic tool is not inducing a false code.
4. Remove the rear bumper cover to gain access to the side object detection modules. This is a necessary step for visual inspection.
5. Visually inspect the passenger-side module and its electrical connector for any signs of water damage, corrosion (white/green powder), physical damage, or a swollen module case.
6. If corrosion is found, the module and its connector pigtail need to be replaced.
7. If no visible damage is found, use a multimeter to test for power, ground, and network activity at the connector according to the factory service manual. A shorted module can sometimes ground out the entire CAN bus, causing wider communication issues.
8. If power and ground are good but there is no network communication, the module has failed internally.

Parts You'll Likely Need

• Side Object Detection Module (Right/Passenger) (OEM #84440528) — This is the sensor module that most commonly fails due to water intrusion, causing the U0268 code. This part number supersedes older versions like 22971841 and 23133813.
  Trusted brands: ACDelco, GM Genuine Parts
  OEM price range: $220-$450
  Aftermarket price range: $200-$350
• Side Object Sensor Connector Pigtail (OEM #ACDelco PT2782 / GM 13585316) — The 8-pin electrical connector attached to the module is often destroyed by the same corrosion and must be replaced.
  Trusted brands: ACDelco, Dorman
  OEM price range: $50-$80
  Aftermarket price range: $30-$50

Related Codes That Often Appear With This One

• U0269 — This is the corresponding 'Lost Communication' code for the driver's side ('A') module. It can appear with U0268 if there is a shared wiring problem or if both modules have failed due to similar environmental exposure.
• U0075 — This is a general code for 'Control Module Communication Bus 'B' Off'. It can be set alongside more specific codes like U0268 when a module on that network stops responding. The TSB PIT5441C lists them together.

Technical Service Bulletins (TSBs) & Recalls

• PIT5441C: Warns that various object detection system codes (including U0268) can be falsely set by a faulty diagnostic interface cable and advises technicians to inspect their equipment.
• N172097060 (Related): While not for the 2018 Traverse, this Special Coverage program for older platform-mates (like the 2013-2017 GMC Acadia) describes the exact same failure mode of water intrusion into the side blind zone alert modules, confirming it's a known GM issue.

Platform-Specific Known Issues

• A known issue documented in TSB #PIT5441C warns that a technician's diagnostic equipment (MDI cable) can sometimes cause false communication codes, including U0268, which is not a fault with the vehicle itself.
• Some owners have reported that condensation from the HVAC system can drip onto the Active Noise Cancellation (ANC) module, causing audio-related symptoms that may occur alongside other electrical issues.
• While not officially recalled for the 2018 Traverse, GM issued a special coverage program (N172097060) for the same issue on prior year platform-mates like the GMC Acadia, acknowledging the design flaw of water intrusion into the modules.

Mechanic-Grade Diagnostic Values

• Low Speed GMLAN Bus Voltage (Normal Communication) — expected: Toggling between 0-5V.. Failure: Circuit stuck high or low, or no activity.
• Low Speed GMLAN Bus Voltage (Wake-Up Pulse) — expected: A pulse of ~10V is sent to wake up modules.. Failure: Absence of a wake-up pulse may indicate an issue with the master module (e.g., BCM or Active Safety Module).
• Low Speed GMLAN Bus Data Rate — expected: 33.3 Kbit/s during normal operation.. Failure: An oscilloscope would show a corrupted or absent data signal.

Scan Tool Commands That Help

• GM GDS2 (Global Diagnostic System 2): SPS (Service Programming System) Programming — This is mandatory after replacing either the left or right Side Object Detection Module. The new module must be programmed with the vehicle's VIN and configuration to be recognized by the network.
• GM GDS2 (Global Diagnostic System 2): Module Diagnostics -> Data Display — Used during initial diagnosis to view live data from the Active Safety Control Module and verify which specific modules on the network are not communicating.
• GM GDS2 (Global Diagnostic System 2): Clear All DTCs — Used after a repair to clear fault codes from all modules. A key cycle is often required. If the U0268 code returns immediately, it indicates the root cause was not resolved.

Wiring & Ground Locations

• Rear Compartment Fuse Box — Located in the rear cargo compartment, accessible via a panel on the side trim.. This fuse box protects and powers various rear electrical components. While the module itself may be powered from elsewhere, related circuits for lighting and other rear functions are located here, and checking for blown fuses is a valid diagnostic step.
• Side Object Detection Module Connector — Plugged into the module itself, located in the corners of the rear bumper, behind the fascia.. This 8-pin connector is the direct interface to the failed module. It is a primary point of failure due to corrosion from water intrusion and must be inspected for green/white powder, bent, or recessed pins.
• Factory Tow Package Connector — On the 2018 Traverse, this connector is located on the rear driver's side panel, behind the bumper cover.. While not directly part of the object detection system, its proximity and shared harness routing mean that any damage or previous work in this area (e.g., aftermarket trailer wiring installation) could potentially damage the harness for the object detection modules.

Real Owner Repair Stories

• GM Service Update 18158 (2018 Chevrolet Equinox (platform-mate with similar system)) — "Service Side Detection (SSD)" message displayed on the Driver Information Center (DIC), and the Side Blind Zone Alert (SBZA) system was not functional.
  ❌ Tried (didn't work) Cycling ignition did not provide a permanent fix.
  ✅ What actually fixed it Dealers were instructed to update the side blind zone alert module with a new calibration file using the Service Programming System (SPS). No parts were required.

OEM Part Supersession History

• 22971841, 23133813 → 84440528 — Manufacturer part update and consolidation.