DTC 78 Foundation Brake

NAME OF CODE:
Foundation Brake

SET CONDITION:
The following criteria must be met for this code to be detected.
1. Vehicle speed above 6 km/h (4 mph) for 2 seconds.
2. Low feedback voltage from the differential pressure assembly (DPA) switch.
3. Criteria 1-3 satisfied for 255 consecutive checks spaced 5 milliseconds (ms) apart (1.3 seconds total).

POSSIBLE CAUSES:
- Anything that keeps the differential pressure switch feedback voltage low
- Shuttled differential pressure switch, (hydraulic leak)
- Short to ground in differential pressure switch circuit