LR3/Disco 3
CENTRAL JUNCTION BOX
The Central Junction box is used to initiate the power up and power down routines within the ECM. When the ignition is
turned on, 12V is applied to the Ignition Sense input to pin 30 of connector C0635. The ECM then starts its power up
routines and turns on the ECM main relay.
When the ignition is turned OFF the ECM will maintain its powered up state for several seconds (this may be up to 20
minutes in extreme cases when cooling fans are required) while it initiates its power down routine and on completion will
turn off the ECM main relay.
POWER SUPPLIES
The ECM requires a permanent battery level voltage supply and a switched battery level voltage supply. The switched
voltage supply is controlled by the ECM via a relay based on the condition of the Central Junction Box input (key position
2).
At key "OFF”, the ECM will maintain the switched supply active until internal self checks have been completed. The Main
Supply fuse is located in the engine compartment fuse box.
PURGE VALVE
Purge Valve and Hoses
P2450
DMTL
COV stuck open
P2451
DMTL
COV stuck closed
P2503
Charging system
Voltage low
P2504
Charging system
Voltage high
P2601
Water pump
Performance fault
P2610
Engine off timer
Timer malfunction
P2632
Secondary fuel pump driver circuit
Output circuit open
P2633
Secondary fuel pump driver circuit
Output low
P2634
Secondary fuel pump driver circuit
High input
P6365
Primary fuel pump
Pump not working when requested
P2636
Secondary fuel pump
Low flow/ performance
