ABS Light Stays On

[DWAlthaus]

I have a 2004 National RV Tropical. The ABS light comes on when the key is turned on and stays on all the time. The RV is on a Freightliner X-Line Chassis. I've seen people talk about intermittent connectors etc but don't know where to find them. Is there some place down by each wheel that the speed sensor is located? Also will the fault clear itself if the faulty connector is fixed? Some places talk about the codes having to be reset with a scan tool but they don't mention if the light will go out before the code is reset. What types of faults commonly cause the ABS light to come on.

Dave Althaus
Fallbrook CA

[Gocoffeer]

Dave: One of the more common issues with ABS systems is a failure of the speed sensor. It is most commonly built into the hub and requires the hub to be replaced on many vehicles. I am not an expert and am not sure about your specific model. In the Diesel shop where I work we use an engine and brake analyzer by WACO to look the the ABS components and not only read codes but test the circuits with the analysis tool. Without that insight you might find it hard to get a most exact direction as to where you can apply your part changing.

[codgerbill]

I have a workhorse chassis. I had an intermittent ABS light that finally stayed on. One place I took it to replaced the sensor and the ABS light went off.....for a couple weeks then came back on intermittently. I took it to another place and the mechanic took his creeper and slid under the coach. He checked the sensor and said it was within specs. He then slid his creeper under the coach to inspect the wiring and discovered a block type connector (located somewhere underneath and close to the passenger seat) that the clips had come loose. After he reseated and put the clips on the ABS light cleared. I had also had a problem with the gas gauge and the transmission not shifting properly. Those problems were also cleared. I think the first place I went to just took a scan gauge reading and replaced the ABS sensor without checking the wiring.