Vehicle: 2001 Nissan Frontier XE, 2WD, L4-2.4L (KA24DE), Automatic Transmission/Transaxle

Mileage: 148,996 miles

Problem: The truck was brought to the shop because the ABS and brake warning lights were on, and the customer said the brake pedal seemed slightly low and spongy.

Case Details: The technician noticed the brake and ABS warning lights were off after starting the engine; but, as soon as he pressed the brake pedal, both lights immediately came on.

The brake fluid was very dark, so he recommended replacing the master cylinder and flushing the brake fluid, but only after determining the core problem. The technician also noticed that he had no communication between his scan tool and the ABS control module.

A quick call to an ALLDATA Tech-Assist consultant gave the technician some valuable insight to help diagnose the core issue. The consultant advised checking brake system fuses 10, 11 and 12 in the under-dash fuse block, then be sure the brake warning light would operate when the parking brake was activated. He also suggested checking the ABS module, which was located under the driver’s seat for moisture intrusion.

If those items were OK, the consultant suggested the technician check for problems with the ABS actuator and electronic control unit, which included the ABS motor.

After following the diagnostic advice and eliminating all other issues, the technician determined the ABS motor located on the ABS actuator and electronic control unit was bad.

Confirmed Repair: He replaced the ABS actuator and electronic control unit, replaced the brake master cylinder with booster, and flushed/bled the brake system. After the repairs, a quick test drive verified the brake and ABS lights stayed off and the brakes operated correctly. Problem solved!