313 AIR not bypassed during KOER

Make
Ford (1981-1995)
Category
Powertrain - Auxiliary Emissions Controls
Severity
Check Engine Light
Applies to
1981-1995 Ford, Lincoln and Mercury EEC-IV vehicles

How to read it

Code 313 reads as 3 flashes, pause, 1 flash, 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 OBD-I code reading guide walks through the paperclip method, code 12, and reading two-digit codes.

What does Ford code 313 mean?

313. AIR not bypassed during KOER. This code sets when your vehicle computer detects air not bypassed during koer.

Common causes of 313

How to fix 313

  1. Check the hose for a blockage or a leak
  2. Check the AIR system for a stuck valve, a blocked passage or a dead pump
  3. Clear the code, then retest to confirm the fix holds

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