Jaguar XJ (X350). Manual — part 110

Levelling Inhibit Function

When the system detects significant cornering, braking and acceleration, it inhibits levelling such that

it will not attempt to compensate for vehicle attitude changes.

Inclination Function

The system enables this function when parking on an uneven surface, (or with a wheel on a kerb, for

example) to ensure the vehicle attitude remains correct when driving off.

Rough Road Detection

When the system detects a rough road surface, the speed lowering function is inhibited, or cancelled,

bringing the vehicle back up to standard ride height to aid passenger comfort.

Trailer Towing Function

When the system detects that the vehicle is towing, (via the connection of the trailer socket) the

speed lowering function is inhibited.

NOTE:

This function will only be enabled by the Jaguar approved towing equipment.

Jacking Function

When the system detects that the vehicle is being jacked, or raised on a wheel-free lift, the vehicle

enters jacking mode, which inhibits lowering to prevent air loss.

Jacking mode is exited when the vehicle is driven, or the ride height passes below a threshold value.

Inspection and Verification

1 . Verify the customer concern.

2 . Confirm which, if any, warning lights and/or messages were displayed on the instrument cluster.

The following messages can be displayed:

•

vehicle too low

•

air suspension fault

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

Mechanical

Electrical

•

Tire pressures

•

Suspension components
(wear/damage/security)

•

Air springs (leakage/damage/tampering)

•

Reservoir

•

Compressor

•

Fuse(s)

•

Wiring harness/electrical connectors

•

Controller area network circuits. For
additional information,

•

Sensors

•

Pipework and unions

•

Sensor fitment

•

Valve block

•

Valve block

•

Air suspension control module (ASU)

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

before proceeding to the next step.

5 . Check the vehicle ride height.

Ride Height Adjustments

6 . 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 diagnostic trouble code (DTC) index chart, or the

symptom chart if no DTCs are set.

Symptom Chart

Symptom

Message

Possible Source

Action

Vehicle sits

too high

and does

not lower

•

Air suspension
fault
(permanent)

•

Vehicle too low
(occasional)

•

Vehicle is in
Transportation
mode

•

Check for DTC C2780

•

The Jaguar approved
diagnostic system is
required to reconfigure
the vehicle into customer
mode

None

•

Vehicle is in Jacking
mode (this does
NOT indicate a
fault)

To verify, drive the vehicle to

above 3 km/h (1.8 mph) to exit

jacking mode and check for

lowering. If the vehicle does not

lower, the system must be tested

using the Jaguar approved

diagnostic system

Vehicle sits

too low

Vehicle too low

(flagged when any

corner is more than 60

mm too low)

•

Low spring pressure
following chassis
rework

•

Spring airline
failure

•

Spring leakage

Run the engine and listen for the

compressor operating:

•

If the vehicle attempts to
lift for 45 seconds, then
flags C2302, check that air
is being delivered to the
air springs by
disconnecting the Voss
fittings at the springs

•

If air is being delivered to
the springs, check the
springs for leakage

•

If air is not being

www.

delivered to the springs,
verify where air flow is
restricted or lost in the air
harness

•

If the vehicle does not
attempt to lift, the system
must be tested using the
Jaguar approved
diagnostic system

None

The reservoir is depleted,

and the vehicle is not below

the compressor activation

height (this does NOT

indicate a fault)

•

If safe, drive the vehicle
steadily to above 40 km/h
(25 mph) for a minimum
5 minutes. Bring the
vehicle to a halt and
check if the vehicle has
lifted

•

If the vehicle does not lift,
the system must be
tested using the Jaguar
approved diagnostic
system

Vehicle

gradually

lowers

while

stationary

None

•

Air spring leak

•

Air harness leak

•

Voss fitting leak

Check the air harness, springs and

fittings for leakage. Rectify as

necessary

Vehicle

attitude is

not flat

after

levelling

None

•

Height sensor
linkage/clip
displaced

•

Water ingress into
the height sensor
connector

•

Visually inspect the
height sensor
linkage/clip. Rectify as
necessary

•

Check the connectors.
Rectify as necessary

Hard ride

None

•

Tire pressures
incorrect

•

Non-standard
wheels/tires

•

Ride height
incorrect

•

Harness fault

•

Air spring fault

Check/adjust the tire pressures.

Make sure that the wheels and

tires are to specification. Check

the ride height.

Ride Height Adjustments

Check

for DTCs indicating a harness or

system fault, refer to the DTC

index. Check the air springs (see

visual inspection).

Soft ride

None

•

Tire pressures
incorrect

Check/adjust the tire pressures.

•

Ride height
incorrect

•

Air spring fault

Check the ride height.

Ride Height Adjustments

Disconnect the electrical

connector from the suspect air

spring and recheck. If the ride is

still soft, install a new air spring.

Front Air Spring (60.32.08)

Rear Air Spring - VIN Range:

G00442->G45703 (60.32.10)

Rear Air Spring - VIN Range:

G45704->G99999 (60.32.10)

Diagnostic Trouble Code (DTC) index

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

Description

Possible Source

Action

B1312

Head lamp circuit

malfunction

•

Head lamp circuit; short
circuit to B+

For headlamp circuit tests,

GO to Pinpoint Test

G256924p2

.

B1342 Control module failure

•

Control module failure

Contact dealer technical

support for confirmation

of control module failure,

and/or raise an EPQR.

B1471 Head lamp circuit

•

Head lamp circuit; open

For headlamp circuit tests,

GO to Pinpoint Test

www.