Scheme 1
| Item Number | Description |
|---|---|
| 1 | Auxiliary junction box |
| 2 | Engine control module (ECM) junction box - right-hand drive vehicles |
| 3 | Engine control module (ECM) junction box - left-hand drive vehicles |
| 4 | Central junction box (CJB) right-hand |
| 5 | Battery junction box (BJB) |
| 6 | High power protection module |
| 7 | Central junction box (CJB) left-hand |
There are six fusebox assemblies per vehicle, five of which have conventional, replaceable fuses. The High Power Protection Module does not have conventional fuses.
Two Engine Control Module (ECM) Junction Box is shown. Only one is fitted (LHD or RHD) to any vehicle, on the opposite side to the pedal box.
The High Power Protection Module comprises of two fusible links to protect the starting circuit and the battery positive supply to the other fuse-boxes.
Principles of Operation
There are three module communication networks connected to the Data Link Connector (DLC), Controller Area Network, (CAN) , Standard Corporate Protocol (SCP) , and International Standards Organization (ISO) . CAN and SCP are unshielded twisted pair cable; data bus + and data bus - , while ISO is a single wire system. (The exceptions to this are the Adaptive Damping Control Module (ADCM) and the Air Conditioning Control Module, (A/CCM) which have two wires). The networks can be connected to the Jaguar approved diagnostic system or scan tool by the DLC.
The SCP communication network remains operational even with the severing of one of the bus wires. Communications will also continue if one of the bus wires is shorted to ground or battery positive voltage (B+), or if some, but not all, termination resistors are lost.
The ISO network, however, will not function if the circuit is damaged.
Modules may log DTCs if power supply or ground is interrupted. Supply and ground tests are in this information under the DTC number flagged, or by module name in the pinpoint tests.
The instrument cluster (also known as an instrument cluster module or ICM) is connected to the CAN and SCP communication networks, and forms a "gateway" between the networks. The networks share information, allowing sensors to serve more than one network.