DD Unable To Enter Spring Fill Diagnostics

Unable to Enter Spring Fill Diagnostics

PINPOINT TEST DD: UNABLE TO ENTER SPRING FILL DIAGNOSTICS:

PINPOINT TEST DD: UNABLE TO ENTER SPRING FILL DIAGNOSTICS (Continued):

Spring Fill Diagnostics has not been entered. There are six possible causes:
1. STAR Tester is inoperative.
2. Brake pressure differential valve warning lamp switch circuit is inoperative.
3. Battery Positive Voltage (B+) power supply circuit is inoperative.
4. Ignition switch circuit is inoperative.
5. Self Test Input (STI) circuit is inoperative.
6. Self Test Output (STO) circuit is inoperative.