Original Porsche Part Genuine Porsche part 99661234800

Front & Rear Brake Pad Wear Sensor
Sold each

Maintain the safety and performance of your Porsche braking system with this OE Match Brake Pad Wear Sensor. Suitable for front and rear brake applications on selected Porsche 986 Boxster, Porsche 996, Porsche 996 turbo and Porsche 997 models, this sensor forms a vital part of the factory brake wear monitoring system.

• Porsche 996 C2 3.4L 1997-08/01
• Porsche 996 C4 3.4L 1997-08/01
• Porsche 996 C2 3.6L 09/01-2005
• Porsche 996 C4 3.6L 09/01-2005
• Porsche 996 C4S 3.6L 09/01-2005
• Porsche 996 TURBO 2000-05

 

• Porsche Boxster 986 2.5L 1997-99
• Porsche Boxster 986 2.7L 1999-02
• Porsche Boxster S 986 3.2L 1999-02
• Porsche Boxster 986 2.7L 2003-04
• Porsche Boxster S 986 3.2L 2003-04

 

• Porsche 997 MK1 Carrera 2 3.6L 2005-08
• Porsche 997 MK1 Carrera 4 3.6L 2005-08

The brake pad wear sensor continuously monitors brake pad thickness and alerts the driver when replacement is required. By providing an early warning before the friction material becomes excessively worn, the sensor helps protect brake discs, maintain braking performance and prevent costly repairs.

For high-performance Porsche sports cars, maintaining the brake wear monitoring system is essential to ensure optimum braking efficiency and vehicle safety.

What Does a Brake Pad Wear Sensor Do?

The brake pad wear sensor is fitted directly into the brake pad and monitors the remaining friction material.

As the brake pad wears down, the sensor eventually contacts the brake disc and completes an electrical circuit that activates the brake wear warning light on the dashboard.

A properly functioning sensor helps:

• Monitor brake pad condition
• Provide early brake wear warnings
• Prevent excessive brake pad wear
• Protect brake discs from damage
• Improve maintenance planning
• Support safe braking performance
• Maintain factory brake monitoring functionality

The sensor serves as an important preventative maintenance tool, helping owners replace brake pads before braking performance is affected.

Why Do Brake Pad Wear Sensors Fail?

Brake wear sensors operate in a demanding environment exposed to heat, vibration, moisture and road contamination.

Common causes of failure include:

• Normal brake pad wear
• Sensor activation after pad wear reaches its limit
• Damaged wiring
• Corrosion in electrical connections
• Heat-related deterioration
• Physical damage during brake servicing
• Water ingress
• Age-related material degradation

Because the sensor is designed to operate alongside the brake pads, it is often recommended to replace the sensor whenever new brake pads are installed.

When Should a Brake Pad Wear Sensor Be Replaced?

Brake wear sensors should be replaced whenever they have been activated, damaged or when brake pads are renewed.

Common signs include:

• Brake wear warning light illuminated
• Intermittent brake warning messages
• Broken or damaged sensor wiring
• False brake wear warnings
• Corroded sensor connectors
• Sensor damage during brake servicing
• Brake pad replacement due to wear

Replacing the sensor during brake maintenance helps ensure the brake monitoring system continues to function correctly.

Why Replacement Matters

A functioning brake wear sensor helps protect your braking system while maintaining safety and reliability.

Benefits include:

• Accurate brake pad monitoring
• Reliable warning light operation
• Improved vehicle safety
• Protection of brake discs
• Reduced maintenance costs
• Better service planning
• Improved braking system reliability
• Long-term braking system protection

For Porsche owners, maintaining the brake wear monitoring system helps preserve the performance, safety and confidence expected from the marque.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99661236501

The product you are viewing cross references to these numbers

Rear Brake Pad Wear Sensor - Sold each

Maintain the safety, reliability and performance of your Porsche braking system with this OE Match Rear Brake Pad Wear Sensor. Designed specifically for Porsche 997 Carrera 2S and Carrera 4S models, this sensor forms a vital part of the factory brake wear monitoring system, helping drivers monitor rear brake pad condition and schedule maintenance before braking performance is affected.


Fits:

• Porsche 997 MK1 Carrera 2S 3.8L 2005-08
• Porsche 997 MK1 Carrera 4S 3.8L 2005-08
• Porsche 997 MKII Carrera C2S 3.8L 2009-12

Installed directly into the rear brake pad assembly, the wear sensor monitors the remaining thickness of the brake pad friction material. When the pads approach their minimum service limit, the sensor activates the dashboard brake wear warning light, alerting the driver that replacement is required.

For high-performance sports cars such as the Porsche 997 Carrera S models, maintaining the brake wear monitoring system is essential for preserving braking efficiency, protecting expensive brake components and ensuring maximum driving confidence.

What Does a Brake Pad Wear Sensor Do?

The brake pad wear sensor continuously monitors brake pad thickness throughout its service life.

As the brake friction material wears down, the sensor eventually contacts the brake disc and completes an electrical circuit, triggering the brake wear warning light on the instrument cluster.

A correctly functioning sensor helps:

• Monitor brake pad condition
• Provide early brake wear warnings
• Prevent excessive brake pad wear
• Protect brake discs from damage
• Improve maintenance scheduling
• Support safe braking performance
• Maintain factory brake monitoring functionality

The sensor acts as an important preventative maintenance component, helping avoid costly brake repairs.

Why Do Brake Pad Wear Sensors Fail?

Brake wear sensors are exposed to extreme operating conditions including heat, vibration, moisture and road contamination.

Common causes of failure include:

• Normal brake pad wear
• Sensor activation when brake pads reach their wear limit
• Damaged wiring
• Corrosion in electrical connectors
• Heat-related deterioration
• Water ingress
• Physical damage during brake servicing
• Age-related material fatigue

As brake wear sensors are considered service items, they should be replaced whenever they become activated or damaged.

When Should a Brake Pad Wear Sensor Be Replaced?

Replacement is recommended whenever brake pads are changed or if the sensor has become damaged.

Common symptoms include:

• Brake wear warning light illuminated
• Intermittent brake warning messages
• Damaged or broken sensor wiring
• False brake wear warnings
• Corroded electrical connections
• Sensor damage during brake servicing
• Rear brake pad replacement due to wear

Replacing the sensor during brake pad replacement ensures the monitoring system continues to function correctly.

Why Replacement Matters

A functioning brake wear sensor helps maintain braking safety and protects expensive brake system components.

Benefits include:

• Accurate brake pad monitoring
• Reliable dashboard warning operation
• Improved braking safety
• Protection of brake discs
• Reduced maintenance costs
• Better servicing planning
• Improved brake system reliability
• Long-term braking component protection

For Porsche 997 owners, maintaining the brake wear monitoring system helps preserve both performance and peace of mind.

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99761267602

The product you are viewing cross references to these numbers

Brake pad wear sensor.
The brake pad wear sensor harness serves as the electrical link between each brake pad wear sensor and the vehicle’s signal/monitoring circuitry (ABS/ECU). As the pads wear down to a threshold level, the sensor completes a circuit that triggers a warning light on the dash, alerting the driver that pad replacement is due.
Sold each.

Fits:

Porsche 996 GT3 MKII 2004 - 2005 Front & Rear

Porsche 997.1 C4 2005 - 2008 Front Caliper
Porsche 997.2 C4 2009 - 2012 Front Caliper
Porsche 997 Turbo / GT2 2007 - 2013 Front Caliper

Porsche GT 2004 - 2006 Rear Caliper


Function:  This harness routes and secures the sensor wiring safely along the suspension and chassis to avoid interference, chafing, or damage. The OE Match harness preserves correct electrical paths and protects the sensor signal from interruption - essential for accurate brake pad condition monitoring.

Brake pad wear sensor systems rely on both the sensor element and the wiring harness to deliver accurate warnings. A damaged or broken harness can interrupt the signal even with new sensors fitted, leading to false “OK” readings or no warning when pads are worn. Replacing the wiring harness with an OE Match unit ensures reliable signal transmission and correct integration with the vehicle’s monitoring systems, helping prevent brake damage or unexpected failures.

When to replace.
Replace this harness if you notice any of the following:
•  Brake wear warning lamp stays off despite worn pads
•  Intermittent or false pad wear warnings
•  Visible frayed wiring, broken connectors, or chafing
•  Previous repairs with generic wiring failed
•  During brake pad or ABS sensor system servicing

Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.

99761267701

The product you are viewing cross references to these numbers