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P0135BMWBMW i4 HubAll BMW P0135Low to Medium Severity

P0135 on BMW i4: Fix & DLC Location

Factory diagnostic troubleshooting wire for fault code P0135 (O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)) specifically on the BMW i4 (2022–2026, Single / Dual Motor EV (eDrive35, eDrive40, M50 536HP)).

2022–2026
i4EV
Sensor Voltage Ref
0.1V – 5.0V Ref
i4 SAE 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 BMW Model:

1. Symptoms of P0135 on BMW i4

When the Engine Control Module (ECM/PCM) on your BMW i4 (Single / Dual Motor EV (eDrive35, eDrive40, M50 536HP)) logs fault code P0135, drivers commonly observe:

Check Engine Light on on BMW i4 (Single / Dual Motor EV (eDrive35, eDrive40, M50 536HP))
Slightly increased fuel consumption on short trips on BMW i4 (Single / Dual Motor EV (eDrive35, eDrive40, M50 536HP))
Failed state emissions inspection on BMW i4 (Single / Dual Motor EV (eDrive35, eDrive40, M50 536HP))
BMW i4 OBD-II Port Location
The 16-pin diagnostic connector is located Under driver steering column OBD interface. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on BMW i4

Historical warranty claims and technical repair bulletins for BMW i4 point to the following failure distribution:

55%
Burnt-out internal heating element in upstream oxygen sensor (BMW OEM Part)
25%
Blown O2 sensor heater fuse (BMW OEM Part)
12%
Melted or damaged sensor wiring near exhaust manifold (BMW OEM Part)
8%
Excessive circuit resistance (BMW OEM Part)

3. Step-by-Step DIY Repair Guide for BMW i4

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 BMW i4 equipped with Single / Dual Motor EV (eDrive35, eDrive40, M50 536HP).

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 BMW i4 equipped with Single / Dual Motor EV (eDrive35, eDrive40, M50 536HP).

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 BMW i4 equipped with Single / Dual Motor EV (eDrive35, eDrive40, M50 536HP).

Other Common Fault Codes on BMW i4

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the BMW i4:

4. BMW i4 P0135 FAQs

What causes code P0135 to trigger on a BMW i4?

On the BMW i4 (Single / Dual Motor EV (eDrive35, eDrive40, M50 536HP)), 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 BMW i4?

On the BMW i4, the 16-pin DLC diagnostic connector is located Under driver steering column OBD interface. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my BMW i4 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.