Vehicle: 2011 Ford F 150, 4WD, V6-3.5L Turbo, Automatic Transmission
Problem: The MIL was ON with DTCs set in ABS module: C109E – Vacuum sensor circuit fault and B1596 – Service continuous codes.
Details: The following are tests recommended by the Tech-Assist consultant and the test results reported by the technician:
Check the brake booster vacuum level (BBVACLVL) PID in scan tool data, which should match actual engine vacuum gauge reading. No, vacuum readings did not match.
Check for 5 volts at brake booster sensor GY/YE wire. Yes, 5 volts reading was present.
Check for ground at brake booster sensor BK-GN wire. Yes, ground was present.
Back-probe brake booster sensor voltage at connector Pin #1 and compare that reading with the “BBAVACLVL” sensor reading on the scan tool – the readings should be equal. No, the voltage readings were not equal.
Check GN/BN wire between brake booster sensor and ABS module pin #10 for open/short circuit. Found an open circuit.
Confirmed Repair: The technician found the GN-BN wire was broken about 12-18 inches from the brake booster sensor. He repaired the wire and that fixed the problem.