628 Excessive torque converter clutch slippage
How to read it
Code 628 reads as 6 flashes, pause, 2 flashes, pause, 8 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 628 mean?
628. Excessive torque converter clutch slippage. This code sets when your vehicle computer detects excessive torque converter clutch slippage.
Common causes of 628
- ATF level/condition
- TCC slipping
- ECM
How to fix 628
- Check the transmission fluid level and condition, and look for slip under load
- Test the ECM last, only after every circuit test has passed
- Clear the code, then retest to confirm the fix holds