The yellow ABS lamp for the trailer stays on after you are moving. What does it mean and what still works?

• A.The trailer has no brakes at all and must be disconnected at once
• B.A steady lamp means ABS is working at maximum power
• C.The lamp concerns only the tractor, never the trailer
• D.The trailer ABS has a fault and may not prevent trailer wheel lockup, but the trailer's regular service brakes still work; drive carefully and get it repaired

Why

ABS is an add-on to the foundation brakes, so its failure removes the anti-lock protection, not the brakes themselves. The correct response is extra care against lockup and prompt repair, not panic.

Manual topic: Combination Vehicles - Trailer ABS · From the Combination Vehicles practice bank (CV-197).

Practice this subject as a full test

More Trailer ABS & Brake Checks questions

• What should the trailer ABS malfunction lamp do when you first power up / start the vehicle, if the system is healthy?
• Where is the ABS malfunction lamp for the trailer itself commonly mounted (in addition to any dash lamp)?
• What is the main safety benefit of trailer ABS for a combination vehicle?
• You couple to an older trailer that was built before ABS was required on trailers. How should that change your driving?
• During the applied-pressure leak test, what maximum air loss in one minute is allowed for a combination vehicle with the engine off and brakes applied?