PISTON GP 5081896 - Caterpillar

Fault Monitoring Systems for the Implement Valve
Illustration 1 g01336584
(1) LED lights on the Implement valve
Table 1
Proportional Valve Electronic (PVE)
Fault Monitoring Specification    
Type     Fault Monitoring     Delay Before Error Out     Error Mode
    Error Output Status
    Fault Output on PVE (1)     LED Light     Memory reset needed    
PVEO
PVEM     No Fault Monitoring                         -    
PVEA     Passive     750 miliseconds     No Fault     Low             -    
Input Signal Faults (2) High     < 2V     Green     -    
Transducer (LVDT) (3) ~ UDC Flashing Red     No    
Closed Loop Fault (4) Constant Red
( 1 ) Measures between fault output pin and ground
( 2 ) Investigate the input signal circuit to determine reason for out of range condition (short to ground, short to battery, etc...). Once the root cause is determined, PVE will need to have power cycled to reset the fault system
( 3 ) This error indicates an internal error in the PVE. The PVE will need to be replaced, as it cannot be disassembled and repaired. (This is a rare fault.)
( 4 ) This will be the most common fault. Cold oil, contamination, and other common causes makes this the hardest fault to diagnose. Active fault shuts down the PVE, so a restart is required. If the fault re-occurs, a logic tree will need to be followed:Is the oil temperature below 00 C (320 F)? and Are other functions also showing faults on their PVEs? etc..
The 414E auxiliary circuit uses a PVEO valve
The 414E lift circuit uses a PVEM valve
The 414E tilt and pitch circuits use a PVEA valveA fault monitoring system is provided in all PVEA modules. The system is available in the passive fault monitoring type. The passive fault monitoring type provides only a warning signal.Note: The 414E uses the passive monitoring system.The passive fault monitoring systems are triggered by three main events:
1. Input signal monitoring: The input signal voltage is continuously monitored. The permissible range is between 15% and 85% of the supply voltage. Outside this range the section will switch into an active error state.
2. Transducer supervision: If one of the wires to the LVDT transducer is broken or short-circuited, the valve section will switch into an active error state.
3. Supervision of the closed loop: The actual position must always correspond to the demanded position (input signal). If the actual spool position is further than the demanded spool position (>12%, PVEA: >25%), the system detects an error and will switch into an active error state. On the other hand, a situation where the actual position is closer to neutral than that demanded will not cause an error state. This situation is considered "in control".Passive fault monitoring
A delay of 250 ms (PVEA: 750 ms) before anything happens.
The solenoid valve bridge will not be disabled but still control the main spool position.
An alarm signal is sent