C1233: On Chevrolet and Buick, right front wheel speed sensor circuit open or shorted
Right front wheel speed sensor circuit open or shorted
Severity: Severity not verified — if the car runs badly, have it inspected
The ABS and traction control lamps stay on and the system may cycle unexpectedly, but none of our sources rate how long driving is safe; the normal brakes still work when ABS is off.
It gets more serious if:
- Inspect soon: Get it checked soon if the ABS cycles during normal braking or the car pulls to one side when you brake. An Impala owner reports both.
C1233 in short
On 2001-2003 Chevrolet and Buick models, C1233 means the right front wheel speed sensor circuit is open or shorted, so ABS and traction control lose that wheel signal. GM bulletin 032503 points to a worn front wheel bearing. Have the brakes checked soon; this page gives no DIY steps.
Each front wheel has a speed sensor that tells the brake control module how fast it is turning. ABS and traction control depend on those signals.
C1233 is stored when the module finds the right front sensor circuit open or shorted. When it sets, the ABS and traction lamps usually come on and the systems switch off.
GM bulletin 032503 covers front wheel bearing replacement for this family of codes on 2001-2003 models, so the bearing and its built-in sensor are part of the check. One Impala owner replaced the hub assemblies on both sides and still had the code, which shows a wiring or module fault is possible too.
Pick your make
C1233 is a manufacturer-specific code: its meaning depends on who built the car.
Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.
Most likely causes
Cause 1: Worn front wheel bearing affecting the speed sensor signal
Supported by vehicle data- Why it ranks here
- GM bulletin 032503 prescribes bearing replacement for C1232 and C1233 on these models.
- What would change this
- Rises if the bearing is noisy or loose. Falls if the hub was already replaced and the code returned.
Cause 2: Wiring or brake control module fault
Possible — needs testing- Why it ranks here
- An Impala owner kept the code after replacing both hub assemblies, so the circuit or module may be at fault, but this is a single report.
- What would change this
- Rises if replacing the bearing did not help. Falls if the code clears after the bearing repair.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: Have a brake technician read the codes and test the right front sensor circuit and bearing with the wheel off the ground.
Warning:ABS and brake work affects stopping ability, and the vehicle must be lifted and supported safely. Do not drive hard with the ABS lamp on, and leave the repair to a trained brake technician.
IfThe bearing or its sensor is worn or damaged
It meansThe bearing is replaced as in the GM bulletin.
Points to: Worn front wheel bearing affecting the speed sensor signal
IfThe bearing is good
It meansThe wiring and control module are tested.
Symptoms
- ABS and traction control lamps on, sometimes intermittently
- ABS cycling during normal braking or a pull to the right when braking Gets more serious: stop and have it checked.
How to fix
This is a safety-critical system, so we explain the code but don't give repair steps. Have it inspected by a qualified technician.
Parts and cost context
- Front wheel bearing and hub:GM bulletin 032503 covers bearing replacement for these codes; labor varies, so get a quote.
Labor varies by vehicle and shop; get a quote before you approve a repair.
Compare used part prices on PartPriceGuideOn your vehicle
ChevroletYour car
2001–2003 · Impala
Supported by vehicle dataGM bulletin 032503 lists C1233 for the 2001-2003 Impala; two owners of 2002 cars store it with ABS and traction lamps on.
2001–2003 · Monte Carlo
Supported by vehicle dataGM bulletin 032503 lists C1233 among front wheel speed sensor codes.
2001–2003 · Venture
Supported by vehicle dataGM bulletin 032503 lists C1233 among front wheel speed sensor codes.
032503 (chevrolet)Status unverified
Front wheel bearing replacement for front wheel speed sensor codes
2001–2003impala, monte-carlo, venture · NHTSA 10001865
Replace the front wheel bearing when the ABS, traction control or service engine soon light is on with front wheel speed sensor codes P1221, P1222, P1225, P1226, C1232 or C1233.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
BuickYour car
2001–2003 · Regal
Supported by vehicle dataGM bulletin 032503 lists C1233 among front wheel speed sensor codes.
2001–2003 · Century
Supported by vehicle dataGM bulletin 032503 lists C1233 among front wheel speed sensor codes.
032503 (buick)Status unverified
Front wheel bearing replacement for front wheel speed sensor codes
2001–2003century, regal · NHTSA 10001865
Replace the front wheel bearing when the ABS, traction control or service engine soon light is on with front wheel speed sensor codes P1221, P1222, P1225, P1226, C1232 or C1233.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.
Related codes
No curated relationships for C1233 yet.
C1233 questions
What does C1233 mean on a Chevrolet Impala?
It is the right front wheel speed sensor circuit open or shorted, according to a code list an Impala owner quotes. GM bulletin 032503 lists it among front wheel speed sensor codes.
Sources and review
- GM bulletin 032503: front wheel bearing replacement for front wheel speed sensor codes
- NHTSA complaint ODI 10224551 (2002 Chevrolet Impala, EBCM code list)
- NHTSA complaint ODI 10839606 (2002 Chevrolet Impala, C1233)
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error