P0137 on GMC Terrain
Factory diagnostic protocol and troubleshooting wire for fault code P0137 specifically for the GMC Terrain (2020–2026, 1.5L Turbo 4-Cyl (175HP) / Denali & AT4 Trim Packages).
1. Symptoms of P0137 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 P0137, 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
Listen for exhaust ticking or black soot around flex pipe, flanges, and sensor bungs before the catalytic converter. on the GMC Terrain equipped with 1.5L Turbo 4-Cyl (175HP) / Denali & AT4 Trim Packages.
Monitor B1S2 voltage. Snap the throttle to enrich mixture; voltage should briefly spike above 0.8V. If it remains 0.0V–0.1V, sensor is defective or shorted. on the GMC Terrain equipped with 1.5L Turbo 4-Cyl (175HP) / Denali & AT4 Trim Packages.
Unplug harness, remove old sensor with 7/8 socket, install replacement sensor and plug firmly. on the GMC Terrain equipped with 1.5L Turbo 4-Cyl (175HP) / Denali & AT4 Trim Packages.
Clear DTCs and verify B1S2 holds steady between 0.45V and 0.75V during steady highway cruising. on the GMC Terrain equipped with 1.5L Turbo 4-Cyl (175HP) / Denali & AT4 Trim Packages.
Equipment for Diagnosing GMC Terrain (P0137)
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 P0137 FAQs
What causes code P0137 to trigger on a GMC Terrain?
On the GMC Terrain (1.5L Turbo 4-Cyl (175HP) / Denali & AT4 Trim Packages), P0137 is most frequently caused by Exhaust leak upstream of or directly at the Sensor 2 bung letting in fresh air or Faulty downstream oxygen sensor.
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 P0137?
Yes. Vehicle is fully drivable, but Check Engine Light will remain illuminated. Given that P0137 carries a Low severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.

