Jaguar XJ (X350). Manual — part 1282

Battery Tray (86.15.11)

Removal

1 . Remove the battery.

For additional information, refer to Battery (86.15.01)

2 . Remove the spare wheel and tire.

3 . Detach the rear power distribution box.

4 . Remove the battery tray.

Installation

1 . To install, reverse the removal procedure.

1) Tighten to 13 Nm.

www.

414-02 : Generator and Regulator

Specifications

Specifications

Torque Specifications

Description

Nm lb-ft lb-in

Generator retaining bolts - vehicles fitted with 3.0L engine

48 35 -

Generator upper retaining bolt - vehicles fitted with 3.5 or 4.2L engine 21 15 -

Generator lower retaining bolt - vehicles fitted with 3.5 or 4.2L engine 40 30 -

Generator retaining bolts - vehicles fitted with 2.7L Diesel engine

47 35 -

Battery positive cable retaining nut

12 9

-

Description and operation

Generator

The generator is belt driven by the accessory drive belt. For additional information, refer to

Accessory Drive (303-05)

When the engine is started, the generator begins to generate alternating current (AC) which is

converted to direct current (DC) internally. The DC current and voltage is controlled by the voltage

regulator, (located inside the generator) and then supplied to the battery through the main battery

positive cable.

The 3.0L generator is solidly mounted to the engine, while the 3.5L and 4.2L generator is pivot

mounted. The 2.7L Diesel generator is also solidly mounted to the engine. The generators are driven

at approximately three times engine speed.

Vehicles fitted with 3.0L engine (L3B generator)

The engine control module (ECM) can switch the voltage regulator between two voltages to optimize

the charging of the battery.

The low voltage regulator setting is 13.6 volts and the high voltage regulator setting 15.3 volts,

measured with the generator at 25°C (77°F) and charging at a rate of 5 amps. These values decrease

with a rise in temperature or current flow.

The ECM determines the output voltage setting of the generator. The high voltage setting is always

selected by the ECM once the vehicle has started. The ECM determines the period of time that the

high voltage setting is selected for.

There are three different time periods selected by the ECM which is dependent upon the vehicle

conditions when the vehicle is started:

•

The longest period of time is selected if the ECM determines that the vehicle has been
'soaking' for sufficient time to allow the engine coolant temperature (ECT) and the air intake
temperature (IAT) to fall within 6°C (43°F) of each other.

•

The intermediate time period is selected when the ECT and the IAT are below 15°C (59°F).

•

The shortest time period is the default time and is used to provide a short period of boost
charge.

At the end of these time periods the voltage is always set to the low voltage setting to prevent the

battery from being over charged.

The time periods are variable depending upon the temperature and battery voltage. The target

voltage of the battery varies between 14 volts and 15 volts depending upon the ambient

temperature and the vehicle operating conditions. Once this target voltage has been achieved,

www.