Q&A

 Journeyman

On Passports there is an issue where a wire harness that runs along the suspension will break due to fatigue. When this happens the anti-lock brake light flashes. As I recall the harness runs along the left side of the vehicle. Honda has put out a bulletin for this problem and the repair is to replace the harness with a new updated piece. You will have to check to see if the harness is still available from the dealer. The best way to check this is to do a visual inspection of the ABS wire harness. Start at the rear differential and follow it along the body to the suspension. As I recall the break in the harness usually happens at the pivot point at the trailing arm. There should be a connector there that attaches to the rest of the ABS harness. If you peel back the plastic cover near the connector you should be able to see either frayed or broken wires. If you find this then the repair will be to replace it with the updated harness from Honda if it's still available.

 Master

The ABS system has two types of Anti lock brakes depending on the production date of your truck. It has one sensor in the differential, its simple to remove and clean off just in case it has picked up debris (this sensor fails a lot on Ford and Volvo installed in the same location), the sensor its self would need to be tested with the vehicle's wheels off the ground and the sensor's out put tested with an oscilloscope to see if it functionally OK. On the earlier production date vehicles the ABS computer is under the drivers seat .
The computer stores codes once it sees a problem with the ABS system but it can only store one code and only stores it if the ignition is left on after seeing the fault. You need to get a workshop manual specific to your car to get the test procedures. The diagnostic connector to extract the codes is at the front kick panel.