Jaguar XJ (X350). Service manual — part 621

Engine cranks and fires,

but will not start

•

Purge valve

•

Fuel pump

•

Engine coolant
temperature (ECT)
sensor

•

Spark plugs

•

HT short to ground
(tracking) check rubber
boots for
cracks/damage

•

Ignition coil failure(s)

•

Harness

For evaporative emissions components,

<<303-13>> Check fuel pressure, <<310-

01>> For ECT sensor tests, <<303-14>> For

ignition system <<303-07>>

Difficult to start cold

•

Check coolant anti-
freeze content

•

Battery

•

CKP sensor

•

EGR valve stuck open

•

Fuel pump

•

Engine coolant
temperature (ECT)
sensor

•

Purge valve

Check engine coolant level and condition.

For battery information, <<414-01>> For

CKP sensor tests, <<303-14>> For EGR

system information, <<303-08>> Check fuel

pressure. <<310-01>> For ECT sensor tests,

<<303-14>> For evaporative emissions

components, <<303-13>>

Difficult to start hot

•

Injector leak

•

Fuel temperature
sensor

•

IAT sensor

•

MAF sensor

•

Purge valve

•

Fuel pump

•

Ignition system

•

Engine coolant
temperature (ECT)
sensor

•

EGR valve stuck open

For fuel injector information,

Fuel Injectors (18.10.02) For fuel

temperature sensor, IAT sensor and MAF

sensor tests, <<303-14>> For evaporative

emissions components, <<303-13>> Check

fuel pressure. <<310-01>> For ignition

system, <<303-07>> For ECT sensor tests,

<<303-14>> For EGR information, <<303-

08>>

Difficult to start after

hot soak (vehicle

standing after engine

has reached operating

temperature)

•

Injector leak

•

Fuel temperature
sensor

•

IAT sensor

•

MAF sensor

•

Purge valve

•

Fuel pump

•

Ignition system

•

Engine coolant
temperature (ECT)
sensor

•

EGR valve stuck open

For fuel injector information,

For fuel temperature sensor, IAT sensor

and MAF sensor tests, <<303-14>> For

evaporative emissions components, <<303-

13>> Check fuel pressure. <<310-01>> For

ignition system, <<303-07>> For ECT sensor

tests, <<303-14>> For EGR information,

<<303-08>>

Engine stalls soon after

start

•

Breather system
disconnected/restricte
d

•

ECM relay

•

Harness

•

MAF sensor

•

Engine coolant
temperature (ECT)
sensor

•

Ignition system

•

Air filter restricted

•

Fuel lines

•

Fuel rail pressure
sensor

•

Air leakage

For breather system information, <<303-

08>> For ECM relay, MAF sensor and ECT

sensor tests, <<303-14>> For ignition

system, <<303-07>> For air filter

information, <<303-12>> For fuel line

information, <<310-01>> For fuel rail

pressure sensor tests, GO to Pinpoint Test

G206886p2.

. For intake system information, <<303-

12>>

Engine hesitates/poor

acceleration

•

Fuel pump

•

Injector leak

•

Fuel pressure

•

Fuel lines

•

Air leakage

•

Throttle sensors

•

Throttle motor

•

Ignition system

•

Exhaust gas
recirculation

•

HO2 sensors

•

Transmission
malfunction

•

Restricted pedal travel
(carpet, etc)

•

APP sensor

Check fuel pressure. <<310-01>> For fuel

rail pressure sensor tests, GO to Pinpoint

Test G206886p2.

. For fuel line information, <<310-01>> For

intake system, <<303-12>> For throttle

position sensor and throttle motor tests,

<<303-14>> For ignition system, <<303-

07>> For exhaust gas recirculation, <<303-

08>> Check for DTCs indicating a faulty HO2

sensor. Refer to the DTC index. For

transmission information, <<307-01>>

Check accelerator pedal travel. For APP

sensor tests, <<303-14>>

Engine backfires

•

Fuel pump

•

Fuel lines

•

Air leakage

•

MAF sensor

•

Oxygen sensors

•

Ignition system

•

Sticking VCT hub

•

APP sensor

Check fuel pressure. <<310-01>> For fuel

line information, <<310-01>> For intake

system, <<303-12>> For MAF sensor tests,

<<303-14>> Check for DTCs indicating a

faulty HO2 sensor. Refer to the DTC index.

For ignition system, <<303-07>> Check

DTCs for VCT range/performance fault. For

VCT information, <<303-01>> For APP

sensor tests, <<303-14>>

Engine surges

•

Fuel pump

•

Fuel lines

•

MAF sensor

•

Harness

•

Throttle sensors

•

Throttle motor

Check fuel pressure. <<310-01>> For fuel

line information, <<310-01>> For MAF

sensor, throttle sensor, and throttle motor

relay tests, <<303-14>> For ignition system,

<<303-07>>

www.

•

Ignition system

Engine

detonates/knocks

•

KS/circuit malfunction

•

Fuel pump

•

Fuel lines

•

FRP sensor

•

MAF sensor

•

Oxygen sensors

•

Air leakage

•

Sticking VCT hub

•

BARO sensor
malfunction

For KS circuit tests, <<303-14>> Check fuel

pressure. <<310-01>> For fuel line

information, <<310-01>> For fuel rail

pressure sensor tests, GO to Pinpoint Test

G206886p2.

. For MAF sensor and oxygen sensor tests,

<<303-14>> For intake system, <<303-12>>

Check DTCs for VCT range/performance

fault. For VCT information, <<303-01>> For

BARO sensor, contact dealer technical

support for advice on possible ECM failure

No throttle response

•

APP sensor malfunction

•

Throttle sensors

•

Throttle motor

For APP sensor, throttle position sensor

and throttle motor relay tests, <<303-14>>

Poor throttle response

•

APP sensor malfunction

•

Throttle sensors

•

Engine coolant
temperature (ECT)
sensor

•

MAF sensor

•

Transmission
malfunction

•

Traction control event

•

Air leakage

•

Breather system
disconnected/restricte
d

For APP sensor, throttle position sensor,

ECT sensor and MAF sensor tests, <<303-

14>> For transmission information, <<307-

01>> For intake system, <<303-12>> For

breather system information, <<303-08>>

Driver Information Chart

Warning

light

Message

Default Mode

DTC

Red

Engine systems fault

Engine shut-down (all

cylinders fuel cut)

P1224

Red

Engine systems fault

Limp-Home

P1229

Red

Engine systems fault

Limp-Home

P0121, P0122, P0123, P0222,

P0223

Red

Engine systems fault

Limp-Home

P1251, P1631

Red

Engine systems fault

Limp-Home

P1611

Red

Engine systems fault

Limp-Home

P1633

Red

Engine systems fault

High idle

P1344, P1122, P1123, P1215,

P1216

Red

Restricted Performance Limp-Home unavailable

P1254

Red

Restricted Performance Limp-Home unavailable

P1250

Red

Restricted Performance Safety redundancy

P1657, P1658

Red

Restricted Performance Safety redundancy

P16634

Amber