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P0140 on RAM: Symptoms, Causes & Fix

O2 Sensor Circuit No Activity (Bank 1 Sensor 2)

Official technical diagnostic wire for fault code P0140 specifically affecting RAM vehicles (1500, 2500, 3500, TRX).

Sensor Voltage Ref
0.1V – 5.0V Ref
RAM 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 RAM Model for P0140:

5 Models Available
RAM 15002020–2026
RAM 1500Truck • 3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar
P0140 Fix & DLC Location
RAM 25002020–2026
RAM 2500Truck • 6.7L Cummins Turbo-Diesel I6 (420HP / 1,075 lb-ft) / 6.4L HEMI V8 (410HP)
P0140 Fix & DLC Location
RAM ProMaster2020–2026
RAM ProMasterVan • 3.6L Pentastar V6 (280HP) / 3.0L EcoDiesel (174HP)
P0140 Fix & DLC Location
RAM 35002020–2026
RAM 3500Truck • 6.7L High-Output Cummins Turbo-Diesel (420HP / 1,075 lb-ft torque / Dual Rear Wheel)
P0140 Fix & DLC Location
RAM 1500 TRX2021–2024
RAM 1500 TRXTruck • 6.2L Supercharged HEMI V8 (702HP / 650 lb-ft / Bilstein Black Hawk e2)
P0140 Fix & DLC Location

1. Common Symptoms on RAM Vehicles

When RAM Engine Control Modules (ECM) trigger fault code P0140, drivers typically report:

Check Engine Light on on RAM Powertrains
Downstream sensor flatlined at static 0.45V bias voltage on RAM Powertrains
Emissions readiness monitor incomplete on RAM Powertrains

2. Root Causes on RAM Engines

Historical diagnostic claims across RAM engines 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)

3. Step-by-Step Fix Protocol for RAM

01
Check Sensor Connection Underbody

Inspect harness connector under vehicle floor pan. Verify plug is firmly seated and weather seal is intact. on RAM engines.

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

Check for 12V heater power and ground at connector with ignition ON. on RAM engines.

Required Tool: Multimeter
03
Replace Downstream Oxygen Sensor

Remove and replace the downstream oxygen sensor with an OEM-spec part. on RAM engines.

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

Clear code and verify sensor activity returns on live telemetry. on RAM engines.

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

Equipment for Diagnosing RAM (P0140)

Prime Fast Delivery & Verified Fitment
Direct-Fit Replacement Part

RAM OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

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

$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 RAMVerified 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.

4. RAM P0140 Frequently Asked Questions

What does code P0140 mean on a RAM?

On RAM vehicles, P0140 indicates that the Engine Control Module (ECM) detected o2 sensor circuit no activity (bank 1 sensor 2). This typically points to Completely dead downstream O2 sensor or Disconnected sensor harness plug under car.

Can I continue driving my RAM with code P0140?

Yes, safe for normal driving without risk of breakdown. Because this code carries a Low severity rating on RAM powertrains, we recommend scanning live data values promptly to prevent secondary damage.

How much does it cost to fix code P0140 on a RAM?

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