OBD-I Codes List

Ford 118 ECT sensor circuit above maximum voltage

Make
Ford (1981-1995)
Category
Powertrain - Fuel/Air Metering
Severity
Check Engine Light

How to read it

Code 118 reads as 1 flash, pause, 1 flash, 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 How to Read Ford EEC-IV Self-Test Codes walks through the test and what the numbers mean. The general OBD-I guide covers the rest.

What does Ford code 118 mean?

ECT sensor circuit above maximum voltage

Common causes of 118

  • The ECT sensor circuit is open, so the ECM reads above maximum voltage.
  • The connector at the ECT sensor is corroded or loose.
  • The ECT sensor failed and reads high.
  • The ECM reads the coolant temperature signal high.

How to fix 118

  1. Check the ECT sensor circuit for an open.
  2. Check the connector pins at the ECT sensor for corrosion or a poor fit.
  3. Test the ECT sensor and replace it only if it fails its own test.
  4. Test the ECM last, only after every circuit test has passed.
  5. Clear the code, then retest to confirm the coolant temperature signal reads in range.

Source

Source review recorded

Sources and review

Review: checked against the recorded source material.

Last updated 2026-10-10.

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