C1234 code in owner complaints

Code C1234 is named in 8 US owner complaints. Models: 4, model years 2001–2014.

There is little data for this code or its meaning is ambiguous, so this page is not indexed.

What the code means

This is a manufacturer-specific code: the meaning depends on the make and sometimes on the year.

How to read C1234: the letter C means chassis (brakes, ABS, steering, suspension); the second digit 1 marks a manufacturer code whose meaning is set by the make; the last three characters 234 identify the specific fault.

ABS/ESC codes: wheel speed sensors, the ABS hydraulic unit and pump, brake booster, pressure and yaw sensors. A hit to a wheel or suspension often damages the wheel speed sensor or its wiring, so on a damaged car this code is a reason to inspect the hub, knuckle and control arms, not just swap the sensor.

Key figures

Complaints with this code: 8
Models: 4
Model years: 2001–2014

Which models and years

Models whose owners name this code (4). Years link to the model year problems page.

Model	Years	Complaints
Toyota Sequoia	2001, 2002	4
Ford Windstar	2003	2
Ford Escape	2005	1
Hyundai Sonata	2014	1

Components named together with the code

Component as the owner filed it (one complaint can list several).

Service brakes 6
Electronic stability control 4
Powertrain 1
Steering 1
Vehicle speed control 1

Complaints by model year

2001 3
2002 1
2003 2
2005 1
2014 1

What to do if an auction car has this code

Inspect the wheel and suspension on the impact side: the wheel speed sensor is often damaged together with the hub or knuckle.
Check whether the ABS and ESC lights stay on after start-up.
After replacing sensors or the hydraulic unit, bleeding and scan tool adaptation may be required.

What owners report

Excerpts of owner complaints in the original wording. Owner statements not verified by the regulator; personal data removed.

ABS module/brakes system goes into limp mode randomly, which causes brake malfunction, throwing codes C1233, C1234 and C1236. There was a recall repair performed by Hyundai about two years ago, however there was two options on NHTSA recall 23V651000/campaign 251.
Hyundai Sonata 2014 · 2026-04
When driving at 70mph or higher a light comes on at the dash board vsc trac off the car loses speed and veers right to left almost loosing control of the steering wheel a diagnostic gave me a code C1234 wich is related with the stability control system yaw rate sensor / computer recalibration.
Toyota Sequoia 2002 · 2019-09
There was a beep at the same time and the trac light and vsc trac light went on. Upon further testing the yaw rate sensor had a fail code of C1234 and the code C1363 booster pedal force switch vault was also affected. Our yaw rate sensor needed replacing. I hear a recall is in the works for this.
Toyota Sequoia 2001 · 2016-06

Related codes

Sources: public official US data (owner complaints) and the SAE J2012 standard. Complaints are owner statements not verified by the regulator. A code from a complaint does not replace a scan tool diagnosis. Data updated 2026-11-10.