OBD-I Codes List

Ford 453 Cruise control servo leaking down during the KOER test

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

How to read it

Code 453 reads as 4 flashes, pause, 5 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 453 mean?

Cruise control servo leaking down during the KOER test

Common causes of 453

  • The cruise control servo diaphragm leaks and cannot hold vacuum down during the KOER test
  • A split or loose vacuum hose between the intake and the cruise servo
  • A sticking servo that drifts out of position once vacuum is applied
  • An internal fault in the PCM cruise control output

How to fix 453

  1. Inspect the vacuum hose from the intake to the cruise servo for cracks or a loose fit
  2. Test the cruise control servo for a vacuum hold and replace it only if it fails
  3. Test the PCM last, only after every circuit test has passed
  4. Clear the code, then retest to confirm the fix holds

Source

Qualified source review

Sources and review

Review: qualified. Read the source limits below.

  • Ford trouble codes, Contour, Escort, Mustang, Probe, Taurus and Tempo 1992-1995 (code, description, probable cause)

    archived reference page (troublecodes.net via Wayback Machine)

    Supports: code identity and probable causes

    Independent table on the same archive site with matching code identity and a probable cause column.

    http://web.archive.org/web/20160501223306id_/http://www.troublecodes.net:80/ford/contour-escort-mustang-probe-taurus-tempo-1992-1995/

  • Ford EEC-IV trouble code table: code, fault location, probable cause (Crown Victoria, Mustang, Taurus, Thunderbird 1992-1995)

    reference page (troublecodes.net)

    Supports: per-code probable causes used for the page cause list and test order

    Fetched 2026-09-30. The probable cause column is what the page lists, in source order, with the test order built from it.

    https://www.troublecodes.net/ford/crown-victoria-mustang-cobralxgt-taurus-thunderbird-1992-1995/

Last updated 2026-10-10.

Report a correction for 453. Include your vehicle, the issue and a source if you have one.

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