Jaguar XJ (X350). Manual — part 738

Description and operation

Starting System

The function of the starting system is to crank the engine fast enough to allow the engine to
start. Heavy cables, connectors and switches are used in the system because of the large
currents required.

The starting system consists of a pre-engaged type starter motor, battery, remote control
switch (ignition switch) and relay. When the starter is operated from the ignition switch, the
engagement lever moves the pinion into mesh with the engine ring gear teeth, the electrical
contacts within the solenoid complete the high power circuit and the starter motor operates to
turn the engine.

Vehicles equipped with automatic transmission have a transmission range sensor attached to
the circuit which prevents operation of the starter motor unless NEUTRAL or PARK are
selected.

The sequence of operation is as follows:

Ignition switch in the start position III.

Starter relay activated.

Voltage provided to the starter motor solenoid.

Starter solenoid engages the drive pinion to the flywheel or flexiplate.

Starter solenoid switches the battery current to the starter motor.

System remains engaged until the ignition switch is returned to the run position.

Diagnosis and testing

Starting System

Overview

There are changes to the engine management system (EMS) for 2006 my, the most obvious of which

will be the change to 7-digit diagnostic trouble codes (DTCs) from the familiar 5-digit.

Refer to the DTC index in this section for guidance on how to use these codes with the Jaguar

approved diagnostic system or a scan tool.

For information on the operation of the system,

Starting System

Inspection and verification

1 . Verify the customer concern.

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

Mechanical

Electrical

Gear selector lever cable adjustment (vehicles with

automatic transmission)

Starter Motor

Battery

Battery charge and condition

Fuses

Wiring harness(es)

Damaged, loose or corroded

connectors

Ignition switch

Starter relay

Transmission control module

(TCM)

Engine control module (ECM)

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

before proceeding to the next step.

4 . If the cause is not visually evident use the Jaguar approved diagnostic system or a scan tool to

retrieve the fault codes before proceeding to the DTC index, or the symptom chart if no DTCs are set.

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Symptom chart

Symptom

Possible cause(s)

Action

The engine does

not crank (starter

motor does not

turn)

Gear selector not in P or N

position (vehicles with
automatic transmission)

Battery

Harness/Connectors

Starter motor

Starter relay

Ignition switch

Transmission control module

(TCM)

Engine control module (ECM)

Engine siezed

Make sure the gear selector is in the P or N

position and correctly adjusted.

Selector Lever Cable Adjustment (44.15.07)

Check the battery condition and state of

charge.

Battery Check the starter motor and harness,

GO to Pinpoint Test G557182p1.

Check the starter relay and circuits. GO to

Pinpoint Test G557182p2.

Check that the engine turns.

The engine does

not crank (starter

motor does turn)

Starter motor fitment

Starter motor

Flywheel/Drive plate ring

gear

Check the starter motor fitment (fasteners

tight, starter motor square to engine, etc).

Check the flywheel/drive plate ring gear teeth

for damage, foreign objects, etc.

Engine cranks too

slowly

Battery

Harness/Connectors

Starter motor

Oil grade

Check the battery condition and state of

charge.

Battery Check the starter motor and harness,

GO to Pinpoint Test G557182p3.

Check the oil specification.

Excessive starter

motor noise

Starter motor

Flywheel/Drive plate ring

gear

Starter motor fitment/casing

Check the starter motor fitment (fasteners

tight, motor square to engine, etc). Check the

starter motor casing condition. Check the

flywheel/drive plate ring gear teeth for

damage, foreign objects, etc.

Generic scan tools may not read the codes listed, or may read only 5-digit codes. Match the 5

digits from the scan tool to the first 5 digits of the 7-digit code listed to identify the fault (the last

2 digits give extra information read by the manufacturer-approved diagnostic system).

NOTE:

For a full list of powertrain DTCs,

Electronic Engine Controls - VIN Range: G00442->G45703

Electronic Engine Controls - VIN Range: G45704->G99999

Electronic Engine Controls - VIN Range: G00442->G45703

Electronic Engine Controls - VIN Range: G45704->G99999

Electronic Engine Controls

DTC

Description

Possible causes

Action

P05120C

Starter request circuit -

circuit voltage above

threshold

Starter relay coil to

ECM/ignition switch
circuit: short circuit to
power

Ignition switch failure

For starter request circuit

tests, GO to Pinpoint Test

G557182p2.

P05120E

Starter request circuit -

circuit voltage below

threshold

Starter relay coil to

ECM/ignition switch
circuit: short circuit to
ground

Starter relay coil to

ECM/ignition switch
circuit: high resistance

Ignition switch failure

For starter request circuit

tests, GO to Pinpoint Test

G557182p2.

P06160E Starter relay circuit low

Starter relay drive circuit:

short circuit to ground

Starter relay drive circuit: high

resistance

Starter relay failure

For starter relay and circuit

tests, GO to Pinpoint Test

G557182p2.

P061700 Starter relay circuit high

Starter relay drive circuit:

short circuit to power

Starter relay failure

For starter relay and circuit

tests, GO to Pinpoint Test

G557182p2.

P06170C Starter relay circuit high

Starter relay drive circuit:

short circuit to power

For starter relay and circuit

tests, GO to Pinpoint Test

DTC index

NOTE:

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