OBD-I Codes List

Ford 74 Brake on/off circuit open during self test

Make
Ford (1981-1995)
Category
Chassis
Severity
Check Engine Light

How to read it

Code 74 reads as 7 flashes, pause, 4 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 74 mean?

Brake on/off circuit open during self test

Common causes of 74

  • The brake pedal was not pressed during the self test, so the brake on/off input stayed open.
  • The brake on/off (BOO) switch failed or is misadjusted.
  • The wiring from the BOO switch is open or damaged.
  • The ECM did not receive the brake on/off signal.

How to fix 74

  1. Check that the brake pedal is pressed during the self test.
  2. Check the brake on/off (BOO) switch and its adjustment.
  3. Check the wiring from the BOO switch to the ECM for an open.
  4. Test the BOO switch and replace it only if it fails its own test.
  5. Test the ECM last, only after every circuit test has passed.
  6. Clear the code, then retest to confirm the brake on/off signal reaches the ECM.

Source

Source review recorded

Sources and review

Review: checked against the recorded source material.

Last updated 2026-10-10.

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