What causes Ford code 226?

The ignition diagnostic module signal was not received by the PCM. The IDM circuit is open. The ICM failed and stopped sending the IDM signal. The PCM cannot read the IDM signal.

How do I fix Ford code 226?

Check the IDM circuit for an open. Check the connector at the ICM for corrosion or a poor fit. Test the ICM 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 IDM signal is received.

Ford 226 Ignition diagnostic module signal not received (EI)

Q: What does Ford code 226 mean?

Ford code 226. Ignition diagnostic module signal not received (EI).

Make: Ford (1981-1995)
Category: Powertrain - Ignition
Severity: Check Engine Light

How to read it

Code 226 reads as 2 flashes, pause, 2 flashes, pause, 6 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 226 mean?

Ignition diagnostic module signal not received (EI)

Common causes of 226

The ignition diagnostic module signal was not received by the PCM.
The IDM circuit is open.
The ICM failed and stopped sending the IDM signal.
The PCM cannot read the IDM signal.

How to fix 226

Check the IDM circuit for an open.
Check the connector at the ICM for corrosion or a poor fit.
Test the ICM 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 IDM signal is received.

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. The three-digit row matches the description used in the data file.
https://web.archive.org/web/20030720231430id_/http://www.troublecodes.net:80/Ford/eec-iv.shtml
Ford trouble codes, Contour, Escort, Mustang, Probe, Taurus and Tempo 1992-1995 (code, description, probable cause)
archived reference page (troublecodes.net via Wayback Machine)
Supports: code identity and probable causes
Independent table on the same archive site with matching code identity and a probable cause column.
http://web.archive.org/web/20160501223306id_/http://www.troublecodes.net:80/ford/contour-escort-mustang-probe-taurus-tempo-1992-1995/
Ford EEC-IV trouble code table: code, fault location, probable cause (Crown Victoria, Mustang, Taurus, Thunderbird 1992-1995)
reference page (troublecodes.net)
Supports: per-code probable causes used for the page cause list and test order
Fetched 2026-09-30. The probable cause column is what the page lists, in source order, with the test order built from it.
https://www.troublecodes.net/ford/crown-victoria-mustang-cobralxgt-taurus-thunderbird-1992-1995/

Last updated 2026-10-10.

Report a correction for 226. Include your vehicle, the issue and a source if you have one.