ABS brake light repairs involve knowing what to do when you see the abs light in your vehicle. When the abs brake light is on, it is a safety warning for you to check your abs brakes right away. Anti-lock braking system or abs is a computerized controlled braking system. It uses indepent braking operation from each vehicle wheel in order to achieve smooth braking action which prevents vehicle spinning as regular brakes do. When troubleshooting, we need to get the error code stored in the computer called abs control unit. It could be a hard abs code or an accidental abs error code but you cannot use the vehicle continuously until you find the meaning of the fault code.
When you see the abs light, there are 2 things you can do to get the abs code:
1.) get the dash panel to flash the code and this feature is available in 1980s vehicles (for 1990s up the present vehicles, please read below). GM, Ford and Chrysler might be different vehicles but on some models, their abs components were made by a common manufacturers like Bosch and Bendix. The abs codes are usually flashed in the dash panel after a pigtail connector wire is grounded. Once the codes are flashed and recorded, it can be fixed by following a troubleshooting charts and wiring diagrams. Once the abs fault is fixed, the abs light could be reset by driving the vehicle at a certain speed. On some Imports models, the abs codes were not flashed in the dash panel if the abs light is on. You have to check manually the specific abs circuit if you want to fix the abs code.
Tips about ABS light repairs on earlier models (1983-1990):
On GM vehicles, you can get the abs code by jumping A and H terminals in the diagnostic terminals connector. With key on, the codes should flash in the dash.
On some vehicles, self diagnostic abs codes are available on the car itself by pushing climate control or abs buttons located in the dash or cycling the ignition keys. Most of these information in retrieving and clearing abs codes are given in the vehicle service manual.
2.) Use an abs code reader to scan the abs light quickly were introduced in the 1990s. Most vehicles used this system in retrieving and clearing the codes. No pigtail or jumper wire is needed which made getting the abs light fast and accurate. Most abs code tester were available only from the dealers such as GM TECH 1, Ford Super Star Testers and Chrysler Diagnostic Readout BOX (DRB). Each Imported vehicles have also their own unique abs code readers to service their abs codes.
Tips about ABS light repairs about abs code readers (1991-present):
The code readers introduced in the early 1990s were basically used to get the abs codes. When troubleshooting, you have to manually check the abs wirings and components to verify it. Later, it was improved so that it can get the code and assist you in finding the abs problem right away. At present, abs code readers are so advanced they can show 2 way communications between the scan tool and the abs control unit. It can display active test functions for every part of the abs without touching the abs components. This is really helpful when trying to access difficult abs sensitive wires and component locations if you do it manual diagnosis.
In summer of 2008, I saw an excellent aftermarket code reader which covers all the latest basic abs tests. It could display and clear codes, show wheel speed sensor readings in action, abs pump motor activities, and perform different tests for cycling ABS components and solenoids when you bleed the brakes. The big difference of this generic abs code reader is the price which sells under $300. I bet if you search Ebay right now, the price could be lower. Just make sure to ask the vendor if the code reader fits your abs before buying it.
When faced with abs brake light repairs, you can fix it yourself using the following steps:
1.) Make a complete basic inspection of your braking system. These includes making sure all the brake pads and shoes are relined and brake fluid levels taken cared of.
2.) Get the abs code using a generic code reader and determine which abs component you have to check. To start, a good visual inspection of the abs system like the master cylinders, accumulators, wheel sensors and hydraulic control unit could be checked for leaks and proper wiring connections. The wheel sensors are usually subject to abuse since it is exposed to vibration and dirt. Located behind the brake rotors, wheel sensors accounts for most of abs failures which you can check by:
testing the wiring connections integrity
making sure the signal teeth is not covered with mud
checking the ground wires are connected properly
3.) Using generic code reader, you can test each abs function separately and if you find a defective electronic part, go ahead and replace it as long as you don’t touch the hydraulic fluid circuits. This assumes the code reader will give you the necessary instructions on how to do it properly. Otherwise, removing any electronic part connected to a pressurized hydraulic system is not recommended.
If the above abs code cannot be fixed, it should be given to the garage since it requires specialized training before you can repair abs difficult problems such as replacements of abs accumulators and abs control unit.
Cautions on abs brake light repairs:
When you have intermittent abs brake lights, always check your front wheel brake sensors. This is specially true if it occurs after a brake job done on your vehicle. Even if you have the abs light on all the time, check those wheel sensors first before you bring the vehicle to the garage. Should you need to replace them, make sure to get a service manual because it has to be adjusted and mounted properly in order to work.
ABS is causing brake pedal to vibrate is commonly caused by dirt or out of adjustment front wheel sensors. This happens if the vibration occurs at lower speed while cruising.
ABS light coming on with a noise when stopping at intersection lights can be tested easily. All you do is dis-able the abs by taking out the abs fuse; drive it and see if the noise stops. If it does, there is a problem in the abs system.
ABS electronic wirings can easily fail if the grounds are loose or corroded. It is important to check them first using a wiring diagram before you bring the vehicle to a garage.
If you need the common fix and wiring diagram for specific vehicle, please contact ATS