128 Manifold absolute pressure sensor vacuum hose damaged or disconnected
How to read it
Code 128 reads as 1 flash, 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 128 mean?
128. Manifold absolute pressure sensor vacuum hose damaged or disconnected. This code sets when your vehicle computer detects manifold absolute pressure sensor vacuum hose damaged or disconnected.
Common causes of 128
- Vacuum or intake leak
- Low fuel pressure or a clogged fuel filter
- Faulty manifold absolute pressure sensor
- Open or shorted wiring or a bad connector in the circuit
- Dirty or weak fuel injectors
How to fix 128
- Confirm the code and read the flash sequence again
- Check for vacuum and intake leaks
- Inspect the manifold absolute pressure sensor and its connector for damage and corrosion
- Measure fuel pressure and check the fuel filter
- Replace the manifold absolute pressure sensor or a failed part only after the tests