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P0135RAMRAM 1500 HubAll RAM P0135Low to Medium Severity

P0135 on RAM 1500: Fix & DLC Location

Factory diagnostic troubleshooting wire for fault code P0135 (O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)) specifically on the RAM 1500 (2020–2026, 3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar).

2020–2026
1500Truck
Sensor Voltage Ref
0.1V – 5.0V Ref
1500 SAE J1979 Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Drivable (Short Trip)
Low to Medium urgency level
Est. DIY Time
45 – 90 Min
Basic hand tools
Check P0135 On Another RAM Model:
RAM 1500

1. Symptoms of P0135 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 P0135, 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)
Slightly increased fuel consumption on short trips on RAM 1500 (3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar)
Failed state emissions inspection 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%
Burnt-out internal heating element in upstream oxygen sensor (RAM OEM Part)
25%
Blown O2 sensor heater fuse (RAM OEM Part)
12%
Melted or damaged sensor wiring near exhaust manifold (RAM OEM Part)
8%
Excessive circuit resistance (RAM OEM Part)

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

01
Check the Heater Fuse

Locate the under-hood fuse box and test the O2 sensor heater fuse with a multimeter or test light. on the RAM 1500 equipped with 3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar.

02
Measure Sensor Heater Resistance

Unplug the Bank 1 Sensor 1 connector and test resistance between the two heater pins (typically 3 to 15 ohms). on the RAM 1500 equipped with 3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar.

03
Replace Upstream O2 Sensor

Use an O2 sensor socket wrench to remove the old sensor from the exhaust manifold and install an OEM-spec replacement with anti-seize on the threads. on the RAM 1500 equipped with 3.0L Hurricane Twin-Turbo I6 (420HP/540HP) / 5.7L HEMI V8 eTorque / 3.6L Pentastar.

Other Common Fault Codes on RAM 1500

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

4. RAM 1500 P0135 FAQs

What causes code P0135 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), P0135 is most frequently caused by Burnt-out internal heating element in upstream oxygen sensor or Blown O2 sensor heater fuse.

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 P0135?

Yes, vehicle is safe to drive, but will stay in open-loop mode longer upon startup. Given that P0135 carries a Low to Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.