C1173 — Park Brake Switch # 1 Released Circuit Short to Gnd

OBD2 code C1173 flags a problem with the ABS / stability control (park brake switch # 1 released circuit short to gnd). Short, gentle driving to a shop is usually possible. Common culprits: damaged sensor wiring or corroded connector, failed wheel speed sensor, faulty ABS module or pump motor.

chassis (brakes/steering/suspension)

Is it safe to drive?

Drive with caution The base brakes usually still work, so careful driving is possible — but ABS and stability control are disabled, which lengthens stopping distances on slippery roads. Fix promptly and avoid harsh driving.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm C1173 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many C0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the ABS / stability control for damage, corrosion, chafing or poor contact.
Subsystem check Read all four wheel speed PIDs while driving slowly — the faulty sensor drops out or reads implausibly.
Subsystem check Inspect the sensor and tone ring for metal debris and damage near the hub.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm C1173 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for C1173 (parts and labor, USD, independent shop rates): Repair sensor wiring: $80–$250; Replace a wheel speed sensor: $120–$350; ABS module repair or replacement: $400–$1,200. Overall, fixing C1173 usually costs between $80 and $1,200. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

Is it safe to drive with C1173?

The base brakes usually still work, so careful driving is possible — but ABS and stability control are disabled, which lengthens stopping distances on slippery roads. Fix promptly and avoid harsh driving.

How do I diagnose C1173 myself?

Start with a scan: confirm C1173, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the ABS / stability control, and verify the suspect component against live data before buying parts.

Will C1173 clear itself?

Sometimes C1173 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What is the most common cause of C1173?

The most common causes are: damaged sensor wiring or corroded connector, failed wheel speed sensor, faulty ABS module or pump motor.

How much does it cost to fix C1173?

Repair sensor wiring — $80–$250; Replace a wheel speed sensor — $120–$350; ABS module repair or replacement — $400–$1,200. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

When your scan tool pulls code C1173, the powertrain or chassis control module has detected that a circuit in the parking brake switch network is behaving incorrectly. Specifically, the fault points to a released-circuit condition where the signal wire is shorted to ground when it should be reading high voltage. C1173 falls under the chassis category, which covers brakes, steering, and suspension systems — meaning the issue touches your vehicle's critical active safety hardware rather than the engine itself.

The ABS and electronic stability control modules constantly monitor the status of parking brake switches and related circuits to coordinate brake apply and release during normal driving, hill starts, and stability interventions. These modules expect specific voltage levels at each input. When the released-circuit short-to-ground condition appears, the module can no longer trust the parking brake switch signal. After the fault persists for a programmed number of drive cycles, C1173 is stored, the warning lamp activates, and certain safety functions may be suspended until the problem is resolved.

Symptoms of C1173

The most obvious sign of C1173 is a warning light on your dashboard — either the ABS lamp, the electronic stability control indicator, or both. Beyond the illuminated warning, drivers commonly report the following:

Dashboard message indicating stability control is disabled or unavailable
ABS system failing to activate during emergency braking maneuvers
Inconsistent or erratic speedometer readings
Cruise control becoming unresponsive or refusing to engage
Noticeable change in brake pedal feel, including unusual pulsation during stops

These symptoms arise because the ABS module detects the fault and enters a protective mode, disabling features that depend on accurate parking brake switch data.

Possible Causes of C1173

C1173 is typically triggered by electrical problems within the brake system's sensor and wiring network rather than mechanical failure. The most frequent culprits include:

Damaged or corroded wiring harness and connectors feeding the parking brake switch circuit
Failed wheel speed sensor providing implausible data to the ABS module
Low supply voltage or a blown fuse feeding the ABS control unit
Faulty ABS module or integrated pump motor unable to process switch inputs correctly
Damaged tone ring (reluctor ring) on the wheel hub causing erratic sensor output
Poor electrical ground connections at the parking brake switch or related modules

How to Diagnose C1173

Effective diagnosis of C1173 requires a systematic approach, starting with data capture and working toward physical inspection. Follow these steps:

Connect a quality OBD2 scanner, confirm C1173 is present, and record all freeze frame data. This snapshot captures engine load, vehicle speed, coolant temperature, and RPM at the exact moment the fault was detected — critical information for recreating the failure condition.
Check for additional diagnostic trouble codes in all modules. Related codes often point to the underlying cause. Also search for any manufacturer technical service bulletins (TSB) that apply to this code on your specific make and model.
Perform a thorough visual inspection of the wiring harness and connectors associated with the parking brake switch and ABS module. Look for damaged insulation, broken wires, corrosion buildup, and loose or partially separated terminals.
Monitor live wheel speed sensor data through your scan tool while driving slowly. A faulty sensor will either drop out completely or display implausible speed readings compared to the other three wheels.
Inspect the tone ring and wheel speed sensor at each hub for metal contamination, physical damage, or incorrect spacing.
After addressing any found issues, clear C1173 and complete a full drive cycle that reproduces the freeze frame conditions. If the code does not return, the repair is confirmed.

Repair Options and Costs

Repair costs for C1173 vary widely depending on which component is at fault. Addressing the least expensive possibilities first is the smart approach:

Sensor wiring repair or connector replacement: $80–$250
Wheel speed sensor replacement (single sensor): $120–$350
ABS module diagnosis, repair, or replacement: $400–$1,200

Labor rates at independent shops typically run $75–$120 per hour. Wiring repairs and sensor replacements are straightforward jobs that usually take under an hour. ABS module replacement or bench repair is more involved and may require programming or calibration.

Driving Safety Verdict: Caution

Your standard friction brakes will continue to function, so the vehicle remains stoppable in an emergency. However, C1173 disables ABS intervention and electronic stability control — systems specifically designed to prevent wheels lockup and maintain directional control on slippery surfaces. Stopping distances increase significantly on wet or icy roads when these features are unavailable. Drive cautiously to a repair facility, avoid aggressive braking and high-speed cornering, and address this code as soon as possible to restore full active safety capability.