OBD-I Codes List

Ford 563 High speed electric fan circuit failure

Make
Ford (1981-1995)
Category
Powertrain - Computer and Auxiliary Controls
Severity
Check Engine Light

How to read it

Code 563 reads as 5 flashes, pause, 6 flashes, pause, 3 flashes on the check-engine light. Jumper the self-test input to signal return at the test connector, then run the key on engine off self test and the running self test, counting the check-engine flashes each time.

New to flash codes? The How to Read Ford EEC-IV Self-Test Codes walks through the test and what the numbers mean. The general OBD-I guide covers the rest.

What does Ford code 563 mean?

High speed electric fan circuit failure

Common causes of 563

  • Wiring
  • Engine coolant blower motor relay/ constant control relay module
  • ECM

How to fix 563

  1. Check the circuit wiring and harness for damage, chafing or a poor splice
  2. Check the cooling system: level, thermostat and circulation
  3. Test the ECM last, only after every circuit test has passed
  4. Clear the code, then retest to confirm the fix holds

Source

Source review recorded

Sources and review

Review: checked against the recorded source material.

Last updated 2026-09-29.

Report a correction for 563. Include your vehicle, the issue and a source if you have one.