abs light

It is flashing the code sequence. The number of flashes represent the digits of the codes. The pause in between the flash sequences means it is about to flash the number of the next digit. Most abs systems are 2 digit codes. So if it flashes 4 times, then a pause, then flashes 5 times your code would be 45. Try it again and see what you have.

 

Just to finish your question, "abs lights", are a PITA!

 

Flash code 23 is a open or shorted wheel speed sensor on the left steer axle if it's a Bendix ABS system. For Wabco, 23 is for the right rear drive modulator valve. So you need to identify the system.

If you don't know and there's no indication on the switch, since your ECU is hidden under your dash, the easiest way is to identify it is to look at the drive ABS relay valve/modulator package. It's usually mounted on the cross-member by the 5th wheel. On a Wabco system, the modulators bolt to the relay valve with 2 bolts each. On a Bendix system, the modulators screw into the relay valve (pipe thread). Or call a dealer with your VIN and they can tell you what you have.

In either case, a wiring issue is the most likely cause. For the steer, it's often a rubbed wire. They zip tie them with the brake hose, so check that out really good. Follow the wire to the plug and you can ohm out the sensor, if it's open or shorted, there's you'r issue, you need a sensor, which is easy on a steer axle.

If it's the rear modulator, it can get a little more involved checking the wiring. Let us know what kind of system you have. Both types of ABS have the troubleshooting manuals online.

When you find the issue, keep in mind that the ABS light might no go out until it senses wheel speed. You often have to drive 5-7 mph so the ECU can complete it's drive away test to clear the lamp.

 

You can drive it, but it is a DOT violation. The ABS light just means that the ABS has an issue and may not be fully working. It does not affect the normal service brakes.

 

i have an 2014 Frieghtliner Cascadia and the abs lights don't come on when running the self diagnostics when i switch on the ignition. fuses and bulbs are good. i can hear the valves clicking when iswitch on the ignition. any ideas?