OBD-I Codes List

Ford 38 Idle speed control or idle tracking throttle position sensor open circuit

Make
Ford (1981-1995)
Category
Powertrain - Computer and Auxiliary Controls
Severity
Check Engine Light

How to read it

Code 38 reads as 3 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 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 38 mean?

Idle speed control or idle tracking throttle position sensor open circuit

Common causes of 38

  • Open idle speed control circuit
  • Faulty idle tracking throttle position sensor
  • Open or shorted wiring harness
  • Corroded connector
  • PCM output fault

How to fix 38

  1. Confirm the code and inspect the idle control connector and wiring
  2. Test the idle speed control for an open winding
  3. Check the idle tracking switch signal through the throttle range
  4. Repair wiring before replacing the control or sensor
  5. Replace the failed part only after the circuit test fails

Source

Source review recorded

Sources and review

Review: checked against the recorded source material.

  • EEC-IV Ford trouble code table (MIL, description, type)

    archived reference page (troublecodes.net via Wayback Machine)

    Supports: code identity and meaning

    Fetched directly. Code row matches the description used in the data file.

    https://web.archive.org/web/20030720231430id_/http://www.troublecodes.net:80/Ford/eec-iv.shtml

Last updated 2026-09-25.

Report a correction for 38. Include your vehicle, the issue and a source if you have one.

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