Pinpoint Test Ah: Reduced System Function

WARNING: This page is about a different car, the 2023 Ford Bronco Sport. However, it is still accessible from the selected car via links, so may be relevant.

Normal Operation and Fault Conditions

The ABS module incorporates a function for testing the vehicle on a dynamometer to prevent wheel speed sensor Diagnostic Trouble Codes (DTCs) from setting during testing. The PCM sends a message to the ABS module when the vehicle is setup for testing. When the ABS module receives this message it knows to ignore discrepancies between the front and rear wheel speed sensors.

The ABS module exits the test mode automatically when the PCM sends the exit message, the ignition is set to OFF, either of the non-driven wheels exceeds 20 km/h (12 mph) or a wheel speed sensor DTC is detected on any wheel speed sensor.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
ABS U2001:00	Reduced System Function: No Sub Type Information	Sets when the ABS module has been set to dynamometer test mode.

Possible Sources

ABS module in test mode

Visual Inspection and Pre-checks

Drive the vehicle above 20 km/h (12 mph). Stop and cycle the ignition from ON to OFF and back to ON. Carry out the ABS module self-test. If the DTC returns, retrieve and diagnose all PCM Diagnostic Trouble Codes (DTCs).

Diagnostic steps are not provided for this symptom or DTC. REFER to: Diagnostic Methods .