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P0137 on Buick: Symptoms, Causes & Fix

O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)

Official technical diagnostic wire for fault code P0137 specifically affecting Buick vehicles (Enclave, Encore GX, Envision, Envista).

Sensor Voltage Ref
0.1V – 5.0V Ref
Buick Factory Standard
CAN Bus Speed
500 kbps CAN-FD
ISO 15765-4 Diagnostic Bus
Drivability Status
Drivable (Short Trip)
Low urgency level
Est. Repair Cost
$100 - $300 (DIY: $35 - $100)
Parts & Labor DIY
Model-Specific Diagnostic Wires

Select Your Buick Model for P0137:

4 Models Available

1. Common Symptoms on Buick Vehicles

When Buick Engine Control Modules (ECM) trigger fault code P0137, drivers typically report:

Check Engine Light on on Buick Powertrains
Downstream sensor voltage consistently below 0.15V on scan tool on Buick Powertrains
Failed emissions test on Buick Powertrains

2. Root Causes on Buick Engines

Historical diagnostic claims across Buick engines point to the following failure distribution:

55%
Exhaust leak upstream of or directly at the Sensor 2 bung letting in fresh air (Buick OEM Part)
25%
Faulty downstream oxygen sensor (Buick OEM Part)
12%
Short to ground in sensor signal wire (Buick OEM Part)
8%
Extremely lean exhaust condition (Buick OEM Part)

3. Step-by-Step Fix Protocol for Buick

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 Buick engines.

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 Buick engines.

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 Buick engines.

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 Buick engines.

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

Equipment for Diagnosing Buick (P0137)

Prime Fast Delivery & Verified Fitment
Direct-Fit Replacement Part

Buick OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Buick.

$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 BuickVerified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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4. Buick P0137 Frequently Asked Questions

What does code P0137 mean on a Buick?

On Buick vehicles, P0137 indicates that the Engine Control Module (ECM) detected o2 sensor circuit low voltage (bank 1 sensor 2). This typically points to Exhaust leak upstream of or directly at the Sensor 2 bung letting in fresh air or Faulty downstream oxygen sensor.

Can I continue driving my Buick with code P0137?

Yes. Vehicle is fully drivable, but Check Engine Light will remain illuminated. Because this code carries a Low severity rating on Buick powertrains, we recommend scanning live data values promptly to prevent secondary damage.

How much does it cost to fix code P0137 on a Buick?

Estimated DIY parts cost ranges from $100 - $300 (DIY: $35 - $100), while professional shop repairs at an authorized Buick dealership or independent specialist typically range from $180 to $380 including diagnostic labor.