C0661 — Left Rear Wheel Speed Sensor B Circuit Low

Q: "Can I drive with this code?"

"It depends on the severity. If the vehicle runs normally, short trips are usually OK. If you notice performance issues, drivability problems, or warning lights beyond the check engine light, get it checked soon."

Q: "Will this code clear itself?"

"Some codes clear automatically after the underlying issue is fixed and several drive cycles pass. But the root cause must be addressed first."

Q: "How do I find the exact cause?"

"A code alone doesn't pinpoint the failed part. You need a diagnostic scan ($50-150 at most shops) that reads freeze frame data and live sensor readings to identify the specific component."

What Does C0661 Mean?

C0661 is a diagnostic trouble code indicating: Left Rear Wheel Speed Sensor B Circuit Low. This code relates to the chassis system. It has been reported in NHTSA complaints across 1 different vehicle models.

Symptoms of C0661

⚠️ Jerking or surging while driving

Common Causes

🔍 Sensor or control module malfunction

Real Owner Reports

From NHTSA complaint database — actual owner descriptions.

"STEERING WHEEL JERKING WHILE IN PARK AND WHILE DRIVING TO THE POINT YOU HAD TO PUT A LOT OF STRENGTH INTO KEEP CAR IN LANE, SERVICE ESC: POWER STEERING WARNING LIGHT CHIMES AND COMES ON WHILE DRIVING, STEERING WHEEL LOCKS UP WHILE TRYING TO PULL OVER ON THE SIDE OF THE ROAD. I TOOK THE CAR TO KIPO C"
— Chevrolet Malibu owner, 02/20/2018

Source: NHTSA Complaints Database

Most Reported Vehicles for C0661

Based on NHTSA owner complaint data.

#	Vehicle	Reports
1	CHEVROLET MALIBU

Frequently Asked Questions

Can I drive with this code?

It depends on the severity. If the vehicle runs normally, short trips are usually OK. If you notice performance issues, drivability problems, or warning lights beyond the check engine light, get it checked soon.

Will this code clear itself?

Some codes clear automatically after the underlying issue is fixed and several drive cycles pass. But the root cause must be addressed first.

How do I find the exact cause?

A code alone doesn't pinpoint the failed part. You need a diagnostic scan ($50-150 at most shops) that reads freeze frame data and live sensor readings to identify the specific component.

What To Do Next

Possible Fixes

🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
🔧 Test the relevant sensor(s) with a multimeter before replacing
🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)

1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

C0661: Left Rear Wheel Speed Sensor B Circuit Low