Diagnosing Passive Wheel Speed Sensors
The passive wheel speed sensor has been around a long time. It works quite differently than the active speed sensors that are found on most cars today. The passive speed sensor creates its own AC signal that changes frequency with wheel speed. This signal is only present while the wheel is turning at a rate fast enough to create the AC signal.
Chrysler Tech Tip: ESP Lamp Flashing/ESP Pump Howl
Some drivers may notice a howl or groan sound while driving straight after a low speed spirited turning event. On SRT vehicles only, when the vehicle has been switched to the “Full On” ESP mode, the ESP event lamp continues to flash. This does not affect the functionality of the ESP system in any way. The system can be returned to “normal Full-On” mode by briefly pressing and releasing the ESP Off switch. The system will reset itself each time the ignition is cycled.
Active Wheel Speed Sensor Diagnostics
There are two “types” of sensors generally found on the modern car – the passive speed sensor and the active speed sensor. They both perform the same function, but work entirely different. The passive speed sensor uses a magnet with fine copper wire wrapped around it to create its own alternating magnetic field. The polarity changes from positive to negative as the tone ring passes by the magnetic field. This frequency changes with wheel speed.
Servicing Wheel Bearings And Wheel Speed Sensors
If you are replacing a wheel bearing on a late-model vehicle, you will be dealing with a wheel speed sensor. In the past decade, wheel speed sensors have been moving from differentials, axles and knuckles to inside or on the wheel bearing or hub unit. At this location, the sensors are more accurate and often more protected from the elements.
How Software Is Changing Braking
There was a time when advancements in brake technology were entirely hardware based. The change from drum brakes to disc brakes, the introduction of semi-metallic and ceramic brake pads, and the addition of power brakes as standard equipment were all changes that were all achieved by redesigned and improved brake system components. Today, electronics is driving most of the advancements in braking technology.
ABS + ESC: Diagnosis of Accelerometers and Yaw Sensors
Accelerometers measure gravitational pull in gravitational force or G-force. Some cars will have one or two sensors depending on sophistication of the system.
ABS/ESC Brake Solenoid Diagnostics
The ABS computer or HCU is a node on a high-speed vehicle bus. This means that the information can be typically accessed through the OBDII DLC. The ABS controller/modulator is the heart of any ABS or ESC system. The modulator gets the brake pressure from the master cylinder. Inside are the valves and solenoids that control the pressures to the wheel. During normal operation, the pressure from the master cylinder goes through the HCU unaltered.
BWD Automotive Releases 370 New Part Numbers
This expanded coverage for BWD is highlighted by 37 new ABS speed sensors for an additional 3 million VIO. Other expanded categories include relays, emission controls, sensors, computerized engine controls and more than 130 new multi-function and combination switches.
Standard Motor Products, Inc. Releases 370 New Parts For Standard And Intermotor
This line expansion features more than 130 new switches including combination, multi-function, cruise control, pedal height adjustment, power seat memory and more, covering greater than 60 million additional VIO.
Electrical: Hand Wire Splicing for Sensitive Connections
A long time ago, I learned a method of splicing wire that has stuck with me since those early days. I actually picked this method up while I was in the military (USMC), so I can’t take credit for inventing it or perfecting it.
Standard Motor Products, Inc. Expands Intermotor Import Line With More Than 1,500 New Parts
Standard Motor Products, Inc. (SMP) has expanded its Intermotor line of genuine import engine control products by adding more than 1,500 import parts in 2012, bringing its total Intermotor line coverage to more than 14,000 genuine import parts.
ABS/ESC: Hydraulic Control Unit/Modulator Diagnostics
Under normal braking conditions, the master cylinder supplies fluid to the HCU and routes the pressure to the calipers. The solenoids are not energized allowing fluid to pass directly from the master cylinder to the caliper. The top solenoid is an isolation valve that isolates the HCU from the master cylinder during stability control interventions;