LR3/Disco 3
Crash Signal
When the RCM (restraints control module) outputs any of the fire signals, it also outputs a hard wired crash signal to the
Engine Control Module (ECM) and changes the high speed CAN (controller area network) bus output message from 'no
crash' to 'crash condition'. The high speed CAN (controller area network) bus message is used by the CJB (central
junction box) and the FFBH (fuel fired booster heater).
On receipt of the crash signals:
The ECM (engine control module) disables the fuel pump.
Operation of the FFBH is disabled.
The CJB (central junction box) enters the crash mode and: Activates all of the unlock signals of the vehicle locking
system, even if the vehicle is already unlocked. After 3 seconds, the CJB (central junction box) activates the
unlock signals again, in case a lock button is pressed during the crash, by flailing limbs for example. Ignores all
locking and superlocking inputs until the crash mode is cancelled, when it returns the locking system to normal
operation. Activates all of the courtesy lamps, except for the approach lamps. The activated courtesy lamps
remain on until they are manually switched off at the lamp unit, or the CJB (central junction box) crash mode is
cancelled, when they return to normal operation. Activates the hazard warning lamps. The hazard warning lamps
remain on until cancelled by turning the ignition switch from position II to position I or 0, or until the crash mode is
cancelled.
Activates all of the unlock signals of the vehicle locking system, even if the vehicle is already unlocked.
After 3 seconds, the CJB (central junction box) activates the unlock signals again, in case a lock button is
pressed during the crash, by flailing limbs for example.
Ignores all locking and superlocking inputs until the crash mode is cancelled, when it returns the locking
system to normal operation.
Activates all of the courtesy lamps, except for the approach lamps. The activated courtesy lamps remain
on until they are manually switched off at the lamp unit, or the CJB (central junction box) crash mode is
cancelled, when they return to normal operation.
Activates the hazard warning lamps. The hazard warning lamps remain on until cancelled by turning the
ignition switch from position II to position I or 0, or until the crash mode is cancelled.
The crash mode is cancelled by cycling the ignition switch.
CONTROL DIAGRAM - SHEET 1 OF 2 (ALL EXCEPT NAS)
NOTE :
A = Hardwired connections; D = High speed CAN (controller area network) bus
