jcb JS300 Service Manual page 481

Removal and Replacement Guide
The engine ECU is a reliable and robust component.
Before removing and replacing the engine ECU carry out
all the relevant diagnostic and fault finding procedures.
Most faults are usually due to damaged wires, connectors
or connected devices such as switches or sensors.
Removal
1 Park the machine and make it safe. Obey the care
and safety procedures. Refer to Section 2,
Maintenance.
2 Carry out the correct power down sequence.
3 Get access to the engine ECU 1. Remove the
applicable cab trim panels. Refer to Section B.
4 Disconnect the harness connectors at the engine
ECU. Do not touch the connector pins. Put some tape
over the connectors to protect the pins.
5 Support the engine ECU and remove four screws 3
together with associated washers. Remove the
engine ECU from the machine.
Replacement
Replace the engine ECU as follows:
1 Install the engine ECU on bracket 2 using screws 3
together with associated washers.
2 Carry out the correct power up procedure.
3 Use Servicemaster to install the ECU software. Refer
to Servicemaster SYSTEM.
4 Use Servicemaster to update the immobiliser lock
K ECU Set-up ( T C-39)
and unlock codes.
Note: Do not replace the ECU with a unit from another
machine. ECU's may look the same but have different
software installations.
C-56
Test Procedures
1 Use the applicable Servicemaster diagnostics tool to
identify faults. Rectify as required.
2 Test the applicable wires and connectors for
continuity, shorts to battery and shorts to earth.
Rectify as required.
9813/5100-1
Section C - Electrics
Electronic Controllers
Engine ECU
1
2
3
Fig 15.
C146620-C1
C-56