521 Power steering pressure switch circuit did not change states KOER
How to read it
Code 521 reads as 5 flashes, pause, 2 flashes, pause, 1 flash 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 OBD-I code reading guide walks through the paperclip method, code 12, and reading two-digit codes.
What does Ford code 521 mean?
521. Power steering pressure switch circuit did not change states KOER. This code sets when your vehicle computer detects power steering pressure switch circuit did not change states koer.
Common causes of 521
- PSP switch not fitted - disregard trouble code
- Wiring
- PSP switch
- ECM
How to fix 521
- Check for PSP switch not fitted - disregard trouble code
- Check the circuit wiring and harness for damage, chafing or a poor splice
- Test the PSP switch and replace it only if it fails its own test
- Test the ECM last, only after every circuit test has passed
- Clear the code, then retest to confirm the fix holds