Short circuit on 24 V of the T.BRK.B signal

What does 231-A020 mean?

This error indicates a short circuit on the +24 V line of the T.BRK.B signal, detected during a braking control test. Specifically, a +24 V signal level is present at the -T.BRK.B input of the SPL module when 0 V is expected, suggesting an issue with the brake control circuit.

• Error during braking control test.
• Signal level is +24 V at input -T.BRK.B of the SPL module although 0 V is expected due to the control.
• External wiring of the brakes or T.BRK signal is faulty (e.g., short to +24 V).
• Brake control relay is defective or stuck.

Click steps to track your progress.

1. 1

   Inspect the external wiring of the brakes and the T.BRK signal for any damage, short circuits, or loose connections.

2. 2

   Measure the voltage at the -T.BRK.B input of the SPL module when 0 V is commanded by the control; it should read 0 V.

3. 3

   Check the functionality of the relay responsible for brake control. Verify its coil and contact states.

4. 4

   Perform continuity tests on the T.BRK.B signal line to ensure no unintentional connection to +24 V.