Jaguar XJ (X350). Manual — part 1272

Diagnosis and testing

Charging System

Principle of operation

For a detailed principle of operation,

Charging System

Inspection and Verification

1 . Verify the customer concern.

2 . Visually inspect for obvious signs of mechanical or electrical damage.

3 . Check the vehicle battery condition and state of charge before condemning any of the charging

system components. For additional information, refer to the battery care manual.

Visual Inspection Chart

Mechanical

Electrical

•

Generator

•

Drive belt

•

Drive belt tensioner

•

Generator pulley

•

Check the security of the
generator fittings

•

Generator

•

Battery

•

Charging system warning light function (ignition ON,
engine OFF)

•

Fuse 33 (5A) (passenger junction fuse box)

•

Fuse 30 (10A) (Rear power distribution box) Vehicles
with 3.5L or 4.2L engine

•

Engine/generator ground connection

•

Circuit(s)

•

Electrical connector(s)

•

Engine control module (ECM)

1 . If an obvious cause for an observed or reported concern is found, correct the cause (if possible)

before proceeding to the next step.

2 . If the cause is not visually evident and the Jaguar approved diagnostic system is not available, use

a scan tool to retrieve the fault codes before proceeding to the Symptom Chart.

CAUTION: When probing connectors to take measurements in the course of the pinpoint

tests, use the adaptor kit, part number 3548-1358-00.

NOTE:

When performing electrical voltage or resistance tests, always use a digital multimeter (DMM)

accurate to 3 decimal places, and with an up-to-date calibration certificate. When testing

resistance, always take the resistance of the DMM leads into account.

NOTE:

Check and rectify basic faults before beginning diagnostic routines involving pinpoint tests.

DTC

Condition

Possible Source

Action

P1146 (V6

only)

Generator

control circuit

low voltage

•

Generator to ECM
control circuit: open
circuit, high
resistance

•

Generator regulator
failure

•

ECM

For generator and control circuit open

circuit and high resistance tests, GO to

Pinpoint Test G215852p1.

.

P1244 (V6

only)

Generator

control circuit

high voltage

•

Generator to ECM
control circuit: short
circuit to high
voltage

•

Generator regulator
failure

•

Generator failure

•

ECM

For generator and control circuit short

circuit tests, GO to Pinpoint Test

G215852p2.

.

P1629 (V6

only)

Generator field

return circuit

failure (battery

warning light

illuminated)

•

Generator field
return circuit: open
circuit, high
resistance, short
circuit

•

Generator regulator
failure

•

Generator failure

•

ECM

For generator field return circuit tests,

GO to Pinpoint Test G215852p3.

.

P1632

Charging system

fault (battery

warning light

illuminated)

•

Accessory drive belt

•

ECM to generator
charge/fault circuit:
short circuit, open
circuit, high
resistance

•

Fuse 30 (10A), rear
power distribution
box (vehicles with

Check the accessory drive belt tension,

<<303-05>> For charge/fault circuit

tests, GO to Pinpoint Test G215852p4.

.

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V8 engine only)

•

Generator failure

•

ECM

P2503

(may also

set P1146)

vehicles

with V6

engine only

Charging system

voltage low

•

B+ cable between
generator and
battery: open
circuit, high
resistance

•

Starter motor
GROUND circuit:
open circuit, high
resistance

•

Generator GROUND
fault

•

ECM

For P1146, GO to Pinpoint Test

G215852p1.

, for charging system circuit tests, GO

to Pinpoint Test G215852p5.

.

P2504

(may also

set P1146)

vehicles

with V6

engine only

Charging system

voltage high

•

Generator failure

•

Charging system
exposed to high
voltage

For P1146, GO to Pinpoint Test

G215852p1.

, for charging system circuit tests, GO

to Pinpoint Test G215852p6.

.

None

The battery

warning light is

on, intermittent,

or flickers with

the engine

running

•

Battery, low voltage

•

Accessory drive belt
tension

•

Fuse 33, passenger
junction box
(vehicles with 3.5L
or 4.2L engine)

•

Generator failure

•

ECM

•

Instrument cluster
(IC) fault

•

Controller area
network (CAN) fault

Check the battery condition and state

of charge. Refer to the battery care

manual. Check the accessory drive belt

tension, <<303-05>> If a generator,

ECM or IC fault occurs, this should be

signalled by the setting of a DTC. For

details of all DTCs set by the ECM,

<<303-14>> For CAN circuit tests,

<<418-00>>

None

The battery keeps

discharging

•

Battery fault

•

Battery quiescent
drain

•

Accessory drive belt
tension

•

Fuse 33, primary
junction box
(vehicles with 3.5L
or 4.2L engine)

•

Generator failure

•

Generator pulley

Check the battery condition and state

of charge. Refer to the battery care

manual. Check the accessory drive belt

tension, <<303-05>> If a generator fault

occurs, this should be signalled by the

setting of a DTC. For details of all DTCs

set by the ECM, <<303-14>> Check that

the generator pulley does not turn

independently of the generator.

fault

None

Generator noisy

•

Generator failure

•

Accessory drive belt
tension

•

Accessory drive belt

•

Accessory drive belt
tensioner

For generator mechanical tests, GO to

Pinpoint Test G215852p8.

. Check the accessory drive belt and

tensioners, <<303-05>>

None

Radio

interference

•

Generator

•

Wiring harness

For interference tests, GO to Pinpoint

Test G215852p9.

.

Pinpoint tests

PINPOINT TEST G215852p1 : P1146:
GENERATOR CONTROL CIRCUIT,
LOW VOLTAGE OR OPEN CIRCUIT

G215852t13 : CHECK THE IGNITION SUPPLY TO THE GENERATOR

1. Turn the ignition switch to the OFF position. 2. Disconnect the generator electrical connector, PI47.

3. Turn the ignition switch to the ON position. 4. Measure the voltage between PI47, pin 02 (GO) and

GROUND.

•

Is the voltage less than 10 volts?

-> Yes

REPAIR the circuit between PI47, pin 02 and battery. This circuit includes the passenger junction fuse

box (fuse 33), the ignition switch and the megafuses. For additional information, refer to the wiring

diagrams. CLEAR the DTC, test the system for normal operation.

-> No

GO to Pinpoint Test G215852t4.

G215852t4 : CHECK THE GENERATOR TO ECM CONTROL CIRCUIT FOR HIGH
RESISTANCE

1. Disconnect the ECM electrical connector, PI01. 2. Measure the resistance between PI47, pin 01

(YR) and PI01, pin 53 (YR).

•

Is the resistance greater than 5 ohms?

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