61, 62, 63 Reset Switch Closed

NAME OF CODE:
61 Right Front Reset Switch Closed
62 Left Front Reset Switch Closed
63 Rear Reset Switch Closed


SET CONDITION:
The following criteria must be met for this trouble code to be detected:

1. CAB not in the antilock pressure control mode.
2. Vehicle speed to have exceeded 8 MPH once since ignition turn on.
3. Reset switch voltage low.
4. Criteria 1 and 2 satisfied for 400 consecutive controller checks spaced 5 ms apart.


THEORY OF OPERATION:
The reset switches are designed to shuttle for either of two hydraulic trouble conditions:

1. Hydraulic pressure difference between the inlet and outlet of each conventional braking circuit through the hydraulic system (caused by an unacceptable restriction).
2. Hydraulic pressure built up in a low pressure accumulator by enough fluid leaking into it to push the accumulator piston full stroke to a hard stop and causing accumulator pressure to exceed 200 PSI.


POSSIBLE CAUSES:
- Anything that keeps the reset switch voltage low when not in the antilock mode
- Isolation orifice blocked during conventional braking
- Dump seat leaking during conventional braking
- Any other hydraulic leak from the conventional braking circuit into one of the low pressure accumulators
- A solenoid valve energized when not in the antilock mode may indicate a defective CAB output
- Stuck reset switch
- Reset switch feedback circuit shorted to ground