What causes Ford code 123?

The TP sensor circuit is shorted to power, so the signal reads above maximum. The TP sensor is loose and its signal jumps above maximum voltage. The TP sensor itself failed and reads high at the top of its travel. The ECM sees the throttle position signal pinned above maximum.

How do I fix Ford code 123?

Check the TP sensor circuit for a short to power. Check that the TP sensor is mounted tight and set correctly. Test the TP 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 signal falls below maximum.

Ford 123 Throttle position sensor circuit above maximum voltage

Q: What does Ford code 123 mean?

Ford code 123. Throttle position sensor circuit above maximum voltage.

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

How to read it

Code 123 reads as 1 flash, pause, 2 flashes, pause, 3 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 123 mean?

Throttle position sensor circuit above maximum voltage

Common causes of 123

The TP sensor circuit is shorted to power, so the signal reads above maximum.
The TP sensor is loose and its signal jumps above maximum voltage.
The TP sensor itself failed and reads high at the top of its travel.
The ECM sees the throttle position signal pinned above maximum.

How to fix 123

Check the TP sensor circuit for a short to power.
Check that the TP sensor is mounted tight and set correctly.
Test the TP 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 signal falls below maximum.

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 123. Include your vehicle, the issue and a source if you have one.