OBD Sensor Power Supply D Circuit/Open
What it means
P26DF stands for Sensor Power Supply D Circuit/Open. P26DF is a P code, so the fault sits in the engine, transmission and emissions systems. For P26DF, the second digit places it in computer output circuits. For P26DF, work through the cause list below, cheapest checks first.
Where it lives
For P26DF, the circuit described runs through the sensor. The description of P26DF reports the sensor as open.
What to check first
For P26DF, check the wiring and connector on this circuit first, since a broken terminal gives the same reading as a failed part.
Check these first
- P26DF: Faulty sensor or actuator in the control circuit
- P26DF: Wiring, connector, or fuse problem for the affected output
- P26DF: Low or unstable system voltage from the battery or charging system
- P26DF: Failed PCM/ECM or a software error
- P26DF: Poor ground connection for the control module
What to do next
P26DF is a fault in the computer output circuits system. The steps below are general, so what actually failed on your vehicle may not be what P26DF names.
- P26DF: Verify battery voltage and charging system health first
- P26DF: Read all related module codes with an OBD-II scanner
- P26DF: Inspect wiring, connectors, and grounds for the affected circuit
- P26DF: Test the sensor or actuator with live data and actuation commands
- P26DF: Check for PCM software updates or TSBs before replacing modules
Look up another code
Enter a full code or a symptom. Press / to search. How to read a code
Type a code above, or start from a symptom or a common code.
Updated
Generic SAE J2012 definition. Last updated 2026-08-30.