MazicBay Diagnostics
MAZICBAYDiagnostics
FTC Reader Disclosure: When you purchase or register through links on our site, we may earn an affiliate commission at no extra cost to you. Read our Editorial & Advertising Policy.

P0137 on Cadillac XT5

O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)

Factory diagnostic protocol and troubleshooting wire for fault code P0137 specifically for the Cadillac XT5 (2020–2026, 2.0L Turbo 4-Cyl (237HP) / 3.6L V6 (LGX 310HP)).

Verified OEM Telemetry & Field Repair Tree
Cadillac XT52020–2026
Cadillac XT5
SUV2.0L Turbo 4-Cyl (237HP) / 3.6L V6 (LGX 310HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
XT5 SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Drivable (Short Trip)
Low urgency level
Est. Repair Cost
$100 - $300 (DIY: $35 - $100)
Parts & Labor DIY
Check P0137 On Another Cadillac Model:
Diagnose P0137 on Specific XT5 Model Year:

1. Symptoms of P0137 on Cadillac XT5

When the Engine Control Module (ECM/PCM) on your Cadillac XT5 (2.0L Turbo 4-Cyl (237HP) / 3.6L V6 (LGX 310HP)) logs fault code P0137, drivers commonly observe:

Check Engine Light on on Cadillac XT5 (2.0L Turbo 4-Cyl (237HP) / 3.6L V6 (LGX 310HP))
Downstream sensor voltage consistently below 0.15V on scan tool on Cadillac XT5 (2.0L Turbo 4-Cyl (237HP) / 3.6L V6 (LGX 310HP))
Failed emissions test on Cadillac XT5 (2.0L Turbo 4-Cyl (237HP) / 3.6L V6 (LGX 310HP))
Cadillac XT5 OBD-II Port Location
The 16-pin diagnostic connector is located Driver side lower dash assembly. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Cadillac XT5

Historical warranty claims and technical repair bulletins for Cadillac XT5 point to the following failure distribution:

55%
Exhaust leak upstream of or directly at the Sensor 2 bung letting in fresh air (Cadillac OEM Part)
25%
Faulty downstream oxygen sensor (Cadillac OEM Part)
12%
Short to ground in sensor signal wire (Cadillac OEM Part)
8%
Extremely lean exhaust condition (Cadillac OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Cadillac XT5.

3. Step-by-Step DIY Repair Guide for Cadillac XT5

01
Inspect Exhaust System for Leaks

Listen for exhaust ticking or black soot around flex pipe, flanges, and sensor bungs before the catalytic converter. on the Cadillac XT5 equipped with 2.0L Turbo 4-Cyl (237HP) / 3.6L V6 (LGX 310HP).

Required Tool: Flashlight, Jack Stands
02
Check Sensor Signal Voltage with Scan Tool

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 Cadillac XT5 equipped with 2.0L Turbo 4-Cyl (237HP) / 3.6L V6 (LGX 310HP).

Required Tool: OBD-II Scanner
03
Replace Downstream O2 Sensor

Unplug harness, remove old sensor with 7/8 socket, install replacement sensor and plug firmly. on the Cadillac XT5 equipped with 2.0L Turbo 4-Cyl (237HP) / 3.6L V6 (LGX 310HP).

Required Tool: O2 Sensor Socket, Ratchet
04
Clear Codes

Clear DTCs and verify B1S2 holds steady between 0.45V and 0.75V during steady highway cruising. on the Cadillac XT5 equipped with 2.0L Turbo 4-Cyl (237HP) / 3.6L V6 (LGX 310HP).

Required Tool: OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Cadillac XT5 (P0137)

Prime Fast Delivery & Verified Fitment
Direct-Fit Replacement Part

Cadillac XT5 OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Cadillac XT5.

$45 – $95 Prime
Check Fitment on Amazon
Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

$29.99 Prime
View on Amazon
Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

Compare OEM & Aftermarket Replacement Sensors for Cadillac XT5Verified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
Find Parts on Amazon
* As an Amazon Associate, MazicBay earns from qualifying purchases. Prices & availability subject to change.

Other Common Fault Codes on Cadillac XT5

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Cadillac XT5:

4. Cadillac XT5 P0137 FAQs

What causes code P0137 to trigger on a Cadillac XT5?

On the Cadillac XT5 (2.0L Turbo 4-Cyl (237HP) / 3.6L V6 (LGX 310HP)), 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 Cadillac XT5?

On the Cadillac XT5, the 16-pin DLC diagnostic connector is located Driver side lower dash assembly. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Cadillac XT5 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.