P0139 on Acura TLX
Factory diagnostic protocol and troubleshooting wire for fault code P0139 specifically for the Acura TLX (2021–2026, 2.0L Turbo (272HP) / Type S 3.0L Turbo V6 (355HP SH-AWD)).
1. Symptoms of P0139 on Acura TLX
When the Engine Control Module (ECM/PCM) on your Acura TLX (2.0L Turbo (272HP) / Type S 3.0L Turbo V6 (355HP SH-AWD)) logs fault code P0139, drivers commonly observe:
2. Most Likely Causes on Acura TLX
Historical warranty claims and technical repair bulletins for Acura TLX point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for Acura TLX
Use scanner graphing mode. Perform rapid deceleration fuel cutoff. Sensor should drop quickly to 0.1V. If response lags by several seconds, sensor is worn. on the Acura TLX equipped with 2.0L Turbo (272HP) / Type S 3.0L Turbo V6 (355HP SH-AWD).
Install new OEM downstream oxygen sensor to restore fast switching response. on the Acura TLX equipped with 2.0L Turbo (272HP) / Type S 3.0L Turbo V6 (355HP SH-AWD).
Clear DTCs and drive at 55 mph for 10 miles to set readiness monitors. on the Acura TLX equipped with 2.0L Turbo (272HP) / Type S 3.0L Turbo V6 (355HP SH-AWD).
Equipment for Diagnosing Acura TLX (P0139)
Acura TLX OEM Replacement Sensor
Direct-fit replacement assembly engineered to OEM tolerances for Acura TLX.
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 Acura TLX
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Acura TLX:
4. Acura TLX P0139 FAQs
What causes code P0139 to trigger on a Acura TLX?
On the Acura TLX (2.0L Turbo (272HP) / Type S 3.0L Turbo V6 (355HP SH-AWD)), P0139 is most frequently caused by Aged and degraded downstream O2 sensor coated in carbon / silicon deposits or Exhaust leak near downstream sensor.
Where is the OBD-II port located on my Acura TLX?
On the Acura TLX, the 16-pin DLC diagnostic connector is located Driver footwell below steering column. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.
Can I safely drive my Acura TLX with code P0139?
Yes. Safe to drive normally, but will fail emissions inspection. Given that P0139 carries a Low severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.

