Ford 454 Cruise control servo leaking up during the KOER test
How to read it
Code 454 reads as 4 flashes, pause, 5 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 454 mean?
Cruise control servo leaking up during the KOER test
Common causes of 454
- The cruise control servo diaphragm leaks and creeps upward during the KOER test
- A split or loose vacuum hose at the cruise servo
- A servo linkage that binds and lets the throttle creep up
- An internal fault in the PCM cruise control output
How to fix 454
- Inspect the vacuum hose and linkage at the cruise servo for damage or binding
- Check the servo cable and linkage for free travel
- Test the cruise control servo for a vacuum hold and replace it only if it fails
- Test the PCM last, only after every circuit test has passed
- 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 454. Include your vehicle, the issue and a source if you have one.
