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P0140RAMRAM 1500 HubAll RAM P0140Low Severity

P0140 on RAM 1500

O2 Sensor Circuit No Activity (Bank 1 Sensor 2)

Factory diagnostic protocol and troubleshooting wire for fault code P0140 specifically for the RAM 1500 (2020–2026, 3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar).

Verified OEM Telemetry & Field Repair Tree
RAM 15002020–2026
RAM 1500
Truck3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
1500 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 P0140 On Another RAM Model:
Diagnose P0140 on Specific 1500 Model Year:

1. Symptoms of P0140 on RAM 1500

When the Engine Control Module (ECM/PCM) on your RAM 1500 (3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar) logs fault code P0140, drivers commonly observe:

Check Engine Light on on RAM 1500 (3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar)
Downstream sensor flatlined at static 0.45V bias voltage on RAM 1500 (3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar)
Emissions readiness monitor incomplete on RAM 1500 (3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar)
RAM 1500 OBD-II Port Location
The 16-pin diagnostic connector is located Driver lower knee bolster panel to the right of parking brake. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on RAM 1500

Historical warranty claims and technical repair bulletins for RAM 1500 point to the following failure distribution:

55%
Completely dead downstream O2 sensor (RAM OEM Part)
25%
Disconnected sensor harness plug under car (RAM OEM Part)
12%
Cut or broken signal wire in vehicle harness (RAM OEM Part)
8%
Corroded terminal pins in connector (RAM OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for RAM 1500.

3. Step-by-Step DIY Repair Guide for RAM 1500

01
Check Sensor Connection Underbody

Inspect harness connector under vehicle floor pan. Verify plug is firmly seated and weather seal is intact. on the RAM 1500 equipped with 3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar.

Required Tool: Flashlight, Jack Stands
02
Test Sensor Heater & Signal Circuit

Check for 12V heater power and ground at connector with ignition ON. on the RAM 1500 equipped with 3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar.

Required Tool: Multimeter
03
Replace Downstream Oxygen Sensor

Remove and replace the downstream oxygen sensor with an OEM-spec part. on the RAM 1500 equipped with 3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar.

Required Tool: O2 Sensor Socket, Ratchet
04
Clear DTC Codes

Clear code and verify sensor activity returns on live telemetry. on the RAM 1500 equipped with 3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar.

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

Equipment for Diagnosing RAM 1500 (P0140)

Prime Fast Delivery & Verified Fitment
Direct-Fit Replacement Part

RAM 1500 OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for RAM 1500.

$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 RAM 1500Verified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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Other Common Fault Codes on RAM 1500

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the RAM 1500:

4. RAM 1500 P0140 FAQs

What causes code P0140 to trigger on a RAM 1500?

On the RAM 1500 (3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar), P0140 is most frequently caused by Completely dead downstream O2 sensor or Disconnected sensor harness plug under car.

Where is the OBD-II port located on my RAM 1500?

On the RAM 1500, the 16-pin DLC diagnostic connector is located Driver lower knee bolster panel to the right of parking brake. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my RAM 1500 with code P0140?

Yes, safe for normal driving without risk of breakdown. Given that P0140 carries a Low severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.