OBD
P263B
MIL Control Circuit High
What it means
P263B stands for MIL Control Circuit High. P263B is a P code, so the fault sits in the engine, transmission and emissions systems. For P263B, the second digit places it in computer output circuits. For P263B, work through the cause list below, cheapest checks first.
What to check first
For P263B, pull the connector and inspect the terminals for spread, corrosion or backed-out pins before testing anything else.
Check these first
- P263B: Faulty sensor or actuator in the control circuit
- P263B: Wiring, connector, or fuse problem for the affected output
- P263B: Low or unstable system voltage from the battery or charging system
- P263B: Failed PCM/ECM or a software error
- P263B: Poor ground connection for the control module
What to do next
P263B reports from the computer output circuits system. These steps cover P263B in general, and the exact cause on your vehicle can differ from the cause named above.
- P263B: Verify battery voltage and charging system health first
- P263B: Read all related module codes with an OBD-II scanner
- P263B: Inspect wiring, connectors, and grounds for the affected circuit
- P263B: Test the sensor or actuator with live data and actuation commands
- P263B: Check for PCM software updates or TSBs before replacing modules
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Updated
Generic SAE J2012 definition. Last updated 2026-08-30.