ABS Archives - UnderhoodService
VIDEO: What Happens When An ABS WSS Fails?

Common wheel bearing failures and the resulting codes. This video is sponsored by BCA Bearings by NTN.

VIDEO: Setting The Air Gap For Wheel Speed Sensors And ABS

You should never remove the wheel speed sensor from a new wheel hub. Here’s why. This video is sponsored by GMB.

ABS Fault Code 02757 Diagnosis Tip

Models: 2011-2014 Jetta, Jetta Sportwagen, Golf/GTI, Tiguan, Eos, 2012-2014 Beetle, Passat.

Toyota Tech Tip: ABS Noise, Warning Lamps And Code C1431

Some 2012-’13 model year Camry vehicles may exhibit a condition where ABS brake actuator pump motor noise is heard from the engine compartment with Brake ABS and/or TRAC warning lamp(s) illuminated and DTC C1431 stored. A poor ground on the left fender side panel bracket may cause this condition after a collision repair.

Indirect Tire Pressure Monitoring Systems Making A Comeback On Some Imports

Indirect Tire Pressure Monitoring Systems (TPMS) are the systems that do not have air pressure sensors inside the tires. Rather, they detect a low tire by comparing relative wheel speeds via the Anti-lock Brake System (ABS) wheel speed sensors. New systems are taking advantage of better wheel speed sensors and modules to make indirect systems work. Indirect TPMS began making a comeback in 2011 on all Audi models. The highly popular Honda Accord switched to indirect TPMS for the 2013 model year.

Chrysler Tech Tip: ETC Light Illuminated Or Diagnostic Trouble Code P2122 And/Or P2127 Set

Some customers may experience an ETC light illumination. Upon further investigation, the technician may find that DTCs P2122 – Accelerator Pedal Position Sensor 1 Circuit Low and/or P2127 – Accelerator Pedal Position Sensor 2 Circuit Low have been set.

VIEWPOINT:Monday Morning MIL Light Quarterback

Monday mornings are typically not very productive for me. I typically will hide in my office with the light off to avoid people asking about their latest weekend-induced car problems.

Tech Tip: Nissan Maxima’s ABS Activates On Normal Braking, ABS Warning Lamp Is On

If you confirm that the ABS light is on with one or more of the following DTCs stored – C1105, C1110, C1124, C1126 – and/or the ABS system activates with normal braking, follow the Service Procedure.

Tech Tip: Generation 1 Wheel Bearings With Integrated ABS Tone Ring

The front wheel bearings listed in this Tech Tip all share a unique design feature. They are all double-row angular contact with a split inner ring. The distinctive feature on these bearings is that one of the two seals on the bearing has a built-in magnetic impulse wheel. Caution should be taken to make sure that the seal with the ABS impulse ring is installed in the correct direction.

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.