158 Mass air flow sensor circuit above maximum voltage
How to read it
Code 158 reads as 1 flash, pause, 5 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 158 mean?
158. Mass air flow sensor circuit above maximum voltage. This code sets when your vehicle computer detects mass air flow sensor circuit above maximum voltage.
Common causes of 158
- Wiring short circuit to positive
- MAF sensor screen blocked
- MAF sensor
- ECM
How to fix 158
- Check the circuit wiring for a short to power
- Test the MAF sensor screen and replace it only if it fails its own test
- Test the MAF sensor 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