B4 Diode Resistor Element, Circuit 531

- Disconnect fluid level switch.

- Connect jumper wire from Circuit 531 (DG/Y) to known chassis ground.

- Observe red brake light.

- Does the brake light function?

YES -- Leave fluid level switch disconnected. Go to B5. [1][2]B5 - Master Cylinder Fluid Level Switch

NO -- Repair open Circuits 977 (P/W), 531 (DG/Y) or open diode/resistor element. Repeat System Pre-Check. Initial Inspection and Diagnostic Overview