U0104 on GMC Terrain
Factory diagnostic protocol and troubleshooting wire for fault code U0104 specifically for the GMC Terrain (2020–2026, 1.5L Turbo 4-Cyl (175HP) / Denali & AT4 Trim Packages).
1. Symptoms of U0104 on GMC Terrain
When the Engine Control Module (ECM/PCM) on your GMC Terrain (1.5L Turbo 4-Cyl (175HP) / Denali & AT4 Trim Packages) logs fault code U0104, drivers commonly observe:
2. Most Likely Causes on GMC Terrain
Historical warranty claims and technical repair bulletins for GMC Terrain point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for GMC Terrain
Clean snow, ice, mud, or dead bugs off front radar emblem. on the GMC Terrain equipped with 1.5L Turbo 4-Cyl (175HP) / Denali & AT4 Trim Packages.
Verify power feed to radar sensor. on the GMC Terrain equipped with 1.5L Turbo 4-Cyl (175HP) / Denali & AT4 Trim Packages.
Execute optical/radar alignment procedure if bumper was removed. on the GMC Terrain equipped with 1.5L Turbo 4-Cyl (175HP) / Denali & AT4 Trim Packages.
Clear DTCs and test cruise on highway. on the GMC Terrain equipped with 1.5L Turbo 4-Cyl (175HP) / Denali & AT4 Trim Packages.
Equipment for Diagnosing GMC Terrain (U0104)
GMC Terrain OEM Replacement Sensor
Direct-fit replacement assembly engineered to OEM tolerances for GMC Terrain.
AstroAI Auto-Ranging Digital Multimeter
Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.
BlueDriver Bluetooth Pro OBDII Scan Tool
Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.
Other Common Fault Codes on GMC Terrain
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the GMC Terrain:
4. GMC Terrain U0104 FAQs
What causes code U0104 to trigger on a GMC Terrain?
On the GMC Terrain (1.5L Turbo 4-Cyl (175HP) / Denali & AT4 Trim Packages), U0104 is most frequently caused by Blocked or dirty front radar sensor in grille/bumper or Blown radar module fuse.
Where is the OBD-II port located on my GMC Terrain?
On the GMC Terrain, the 16-pin DLC diagnostic connector is located Driver footwell directly above brake pedal. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.
Can I safely drive my GMC Terrain with code U0104?
Yes. Normal driving is unaffected, but Adaptive Cruise Control will not engage. Given that U0104 carries a Low severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.