U0075 on 2017-2018 Cadillac XT5: Active Safety Communication Failure Causes and Fixes

What's Unique About the 2017-2018 Cadillac XT5

For this specific vehicle, General Motors issued Technical Service Bulletin #PIT5441C, which directly addresses code U0075 along with a cluster of other 'U' codes related to the Active Safety Module. The bulletin points technicians to diagnose a specific communication bus used for object detection, highlighting that the issue is often network-related rather than a simple part failure. It even notes that diagnostic tool cable issues can sometimes trigger these codes, indicating the sensitivity of this particular network which uses DLC pins 3 and 11. A second TSB, #PIT5700B, identifies specific wiring harness failure points near the driver's seat (harness junction JX300) and A-pillar (connector X203) that can cause this code on the XT5 and its platform mates.

Diagnostic Flowchart

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

Symptoms You May Notice

• Warning message on the driver information center, such as 'Service Active Safety', 'Service Front Camera', or 'Steering Assist is Reduced'
• Check Engine Light may be illuminated
• Advanced safety features like Adaptive Cruise Control, Lane Keep Assist (LKA), and park assist become inoperative
• The LKA indicator in the instrument cluster may not illuminate.
• Side impact, rear cross traffic, and forward collision warnings become unavailable.

Most Likely Causes

1. Wiring or Connector Issue 🔴 High Probability Vehicle wiring harnesses can be susceptible to corrosion, chafing, or loose pins at connectors. TSB PIT5700B specifically points to potential open circuits on the low-speed communication line (circuit 5060) near harness junction JX300 (located on the floor near the driver's seat on the related GMC Acadia) or at the A-pillar connector (X203) as a cause for lost communication with the Active Safety Control Module. GM has also issued engineering information requests to gather data on wiring harness damage on the 2020 XT5.
   How to confirm: A technician will use a multimeter to check for continuity and proper voltage on the communication bus circuits (specifically circuits 3813, 3811, and 5060 🎬 See this guide on finding CAN bus faults with a multimeter.) at the module connector and data link connector. Visual inspection of harnesses for damage is critical, especially at the base of the A-pillar and under the driver's seat carpet.
   Typical fix: Repairing the damaged section of the wire (pigtail connectors are available) or cleaning/re-seating the connector. GM provides specific instructions for warranty-covered wiring repairs under bulletin 10-00-89-005.
   Est. part cost: $20-$100
2. Faulty Active Safety Control Module (ASCM) 🟡 Medium Probability → Shop Active Safety Control Module Bracket Bolt Like any electronic component, control modules can fail internally. A technician on a related forum described a module as being 'bricked', which was resolved by replacement. This can prevent them from transmitting or receiving data on the network.
   How to confirm: After confirming the wiring, power, and ground to the module are good, a technician will use a high-level scan tool to attempt to communicate directly with the ASCM (K124). If it fails to respond, the module is likely faulty.
   Typical fix: Replacement of the Active Safety Control Module. The new module will require programming by a dealer or qualified shop to work with the vehicle.
   Est. part cost: $400-$800
3. Weak or Failing Battery ⚪ Low Probability → Shop Vehicle Battery Modern vehicles like the XT5 are packed with electronics that are highly sensitive to voltage. A weak battery can cause voltage drops during startup or auto start/stop events 🎬 Watch: How a weak battery affects the auto start/stop system., leading to random communication errors between modules. A GM TSB for the platform-mate Buick Enclave explicitly states that 'Stable battery voltage is critical during programming' and that any fluctuation can interrupt module communication.
   How to confirm: Test the battery with a professional digital battery tester that can measure voltage and cold cranking amps under load. A simple voltage test is often not sufficient.
   Typical fix: Replace the battery with a high-quality AGM (Absorbent Glass Mat) battery that meets or exceeds OEM specifications.
   Est. part cost: $200-$350

Rare But Worth Checking

• Diagnostic Tool or Cable Issue: TSB #PIT5441C specifically mentions that a faulty MDI (Multiple Diagnostic Interface) or its cable can cause false U-codes, including U0075, to be set. This is because the object detection bus communicates on DLC pins 3 and 11, which may be less frequently used and could have a hidden fault in the diagnostic tool itself.
• Software/Firmware Issue: GM has issued bulletins (e.g., PIC6424A) for situations where a replacement Active Safety Control Module fails during programming because the new hardware is incompatible with the older software in the programming system. This indicates that software conflicts can be a source of problems with this module.

Diagnosis Steps

1. Connect a professional scan tool capable of reading GM-specific codes from all modules. Before diagnosing, rule out a faulty scan tool cable per TSB #PIT5441C.
2. Check for TSBs #PIT5441C and #PIT5700B.
3. Using a data bus diagnostic tool, check for communication with the Active Safety Control Module (K124) and the Front View Camera Module (B174W) on the low-speed bus (DLC terminal 1).
4. If the K124 ASCM is not communicating, inspect the battery and charging system to ensure stable voltage.
5. Visually inspect the wiring harness leading to the ASCM. Per TSB #PIT5700B, pay close attention to the harness near junction JX300 (under carpet near driver's seat) and connector X203 at the base of the A-pillar for chafing, corrosion, or damage.
6. Using a wiring diagram, test for proper power, ground, and network circuit integrity (circuits 5060, 3813, 3811) at the ASCM connector with a multimeter.
7. If wiring, power, and ground are confirmed good, but the module still won't communicate, the Active Safety Control Module is the likely point of failure and requires replacement and programming.

Parts You'll Likely Need

• Active Safety Control Module (OEM #84737638, 84356794 (supercedes multiple older numbers)) — If wiring and power are good, the module itself is the most likely failure point causing a total loss of communication.
  Trusted brands: ACDelco, GM Genuine Parts
  OEM price range: $400-$800
  Aftermarket price range: $300-$600
• AGM Battery — Low system voltage from a weak battery is a known cause of intermittent communication faults on modern GM vehicles.
  Trusted brands: ACDelco, DieHard, Odyssey
  OEM price range: $250-$350
  Aftermarket price range: $200-$300
• Wiring Harness Pigtail Connector — If a wiring fault is found at a connector, a pigtail may be needed for the repair, as recommended by TSBs.
  Trusted brands: ACDelco, Duralast
  OEM price range: $40-$80
  Aftermarket price range: $25-$50

Related Codes That Often Appear With This One

• U026A — These codes are listed together in TSB #PIT5441C as being related to the Active Safety Module and object detection system communication failures.
• U026B — These codes are listed together in TSB #PIT5441C as being related to the Active Safety Module and object detection system communication failures.
• U026C — These codes are listed together in TSB #PIT5441C as being related to the Active Safety Module and object detection system communication failures.
• U0265 — These codes are listed together in TSB #PIT5441C as being related to the Active Safety Module and object detection system communication failures.
• U0268 — These codes are listed together in TSB #PIT5441C as being related to the Active Safety Module and object detection system communication failures.
• U0269 — These codes are listed together in TSB #PIT5441C as being related to the Active Safety Module and object detection system communication failures.

Technical Service Bulletins (TSBs) & Recalls

• PIT5441C: Addresses DTC U0075 and other codes related to the Object Detection System, noting that a faulty diagnostic tool (MDI) or cab

Platform-Specific Known Issues

• TSB #PIT5441C directly links U0075 to the object detection system on GM vehicles and warns that faulty diagnostic equipment can induce the code.
• TSB #PIT5700B identifies specific locations for open circuits that can cause the Active Safety Control Module to lose communication on 2017-2020 XT5 models, specifically near the driver's seat and A-pillar.

Mechanic-Grade Diagnostic Values

• CAN Bus Network Resistance — expected: ~60 Ohms. Failure: A reading of ~120 Ohms indicates one of the two terminating resistors is offline or there is a break in the circuit. A reading of 0 Ohms or an open line (OL) indicates a short or complete break in the network.
• CAN High (CAN_H) to Ground Resistance — expected: High resistance, typically in the kOhm or MOhm range.. Failure: Low resistance (near 0 Ohms) indicates a short to ground.
• CAN Low (CAN_L) to Ground Resistance — expected: High resistance, typically in the kOhm or MOhm range.. Failure: Low resistance (near 0 Ohms) indicates a short to ground.

Scan Tool Commands That Help

• GDS2 (Global Diagnostic System 2): K124 Active Safety Control Module: Programming and Setup — This function is required after replacing the Active Safety Control Module (ASCM) to load the correct software and configure it for the specific vehicle. It is also used to apply software updates issued by GM to fix bugs, such as one that caused unnecessary automatic braking.
• GDS2 (Global Diagnostic System 2): Clear All DTCs — After a successful reprogramming of the ASCM or any other module, it is necessary to clear all stored Diagnostic Trouble Codes from the vehicle's memory.

Wiring & Ground Locations

• X203 — A 16-way female connector located where the headliner wiring harness connects to the main instrument panel harness, often near the A-pillar.. TSB #PIT5700B identifies this connector as a potential point for an open circuit on the communication line to the Active Safety Control Module. A loose pin or corrosion here can cause a loss of communication and set code U0075.
• JX300 — A harness junction located on the floor, under the carpet near the driver's seat (location confirmed on the related GMC Acadia platform).. TSB #PIT5700B also points to this junction as a common location for wiring issues. Water intrusion or chafing from seat movement can damage the communication circuits that pass through this area.
• K124 — The Active Safety Control Module itself. Its exact location can vary but is typically mounted securely within the cabin, often behind the dashboard or in the center console area.. This is the module that is failing to communicate. All diagnostic paths lead here, requiring checks of its power, ground, and network connections at its main connector.

OEM Part Supersession History

• 84218070 → 84356794, 84737638 — Standard part evolution for hardware revisions or software compatibility updates.
  Heads up: When replacing the Active Safety Control Module, the new part must be programmed by a dealer using GDS2. Failure to program will result in the module not functioning. GM has also issued bulletins regarding programming failures if the dealer's software is not up to date before attempting to program a newer module.

Model Year Variations Within This Range

• 2017-2018: There are no significant mechanical or electronic differences between the 2017 and 2018 Cadillac XT5 models that would affect the diagnosis or common causes of code U0075. Both model years use the same 3.6L V6 engine and have the same ADAS hardware options available.