Is it safe to drive with this code?

Your conventional brakes typically remain functional, but the ABS or traction-control system may be disabled. Avoid hard braking and slippery conditions, and drive cautiously to a garage for diagnosis – see our safety disclaimer for more detail.

Potentially, yes – if the ABS or brake-system warning lamp is illuminated at the time of the test, the examiner will record a major defect. Refer to our MOT disclaimer for specifics on lighting-related failures.

Roughly how much does it cost to fix?

If it's a simple relay or connector fault, expect low two-figure costs for parts plus an hour's labour. If the ABS module needs repair or replacement, costs can climb into the mid or high three-figure range – sometimes four-figure at a main dealer. Location, vehicle age and whether you choose an independent workshop or a franchised dealer all influence the final bill.

Can a bad relay affect my cruise control?

Yes – many systems cancel cruise control when they detect a brake-circuit anomaly to ensure the vehicle can stop safely. Fixing the relay circuit often restores cruise functionality.

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← All fault codes | ABS / ESP

C0177

Chassis

ABS/TCS Brake Lamp Relay Circuit Range/Performance

The ABS or traction-control module has detected an out-of-range signal from the brake lamp relay circuit, which may prevent the system from controlling brake lights correctly during anti-lock events.

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ⓘ Information only. This page provides general educational information about fault code C0177. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.

Recommended next steps

Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.

What does C0177 mean?

C0177 is a Chassis (ABS, traction control, steering) fault code. It indicates: ABS/TCS Brake Lamp Relay Circuit Range/Performance.

This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.

About ABS / ESP codes

Codes in this category relate to the anti-lock braking system (ABS) and electronic stability control (ESP/ESC). These systems share wheel speed sensors, hydraulic modulators, and a common control module. Faults here usually disable ABS pulse braking and stability control assistance, but standard hydraulic brakes continue working normally.

C0177 is one of 429 codes in this category. Browse all ABS / ESP codes →

What we know about C0177 specifically

We record the SAE J2012 standardised definition and the system this code belongs to, but we have not yet published detailed driver-reported symptoms, common causes, or step-by-step diagnostic guidance for C0177.

Rather than invent that information by generating generic content from a template, we leave it out. For specific guidance, the most reliable sources are:

•your vehicle's own service manual or manufacturer-specific technical bulletins
•a qualified mechanic with a manufacturer-level diagnostic tool
•a marque specialist familiar with your make and model

Codes nearby

Codes adjacent to C0177 in the C-code series. Many fault codes appear together with their neighbours because they relate to the same circuit or component.

C0163 ABS/TCS Brake Switch Circuit Low

C0164 ABS/TCS Brake Switch Circuit High

C0176 ABS/TCS Brake Lamp Relay Circuit

C0178 ABS/TCS Brake Lamp Relay Circuit Low

C0179 ABS/TCS Brake Lamp Relay Circuit High

C0186 ABS/TCS Brake Lamp Switch Circuit

Other ABS / ESP codes

Other fault codes in the same system as C0177. The ones with detailed guides have plain-English explanations, symptoms, causes, and diagnostic steps.

B1106

Shift Lock Circuit Failure Detailed guide

C0021

Left Front Wheel Speed Sensor Circuit Detailed guide

C0035

Left Front Wheel Speed Sensor Circuit Range/Performance Detailed guide

C1000

Abnormality in Stoplight Switch Circuit Detailed guide

C1602

Manufacturer-Specific Chassis/ABS Fault Detailed guide

B1082

ORC-Occupant Restraint Control-Fps-Fire Protection Strategy-Activated

Spotted an issue or have something to add? Mechanics, technicians, and drivers who have first-hand experience with C0177 can submit a correction or expansion. We review every submission before publishing, mechanic submissions are prioritised.

Information only, not professional advice

The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →

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