Jaguar XJ (X350). Manual — part 749

Is the voltage greater than 3 volts?

-> Yes

REPAIR the short to B+ voltage. For additional information, refer to the wiring diagrams. CLEAR the

DTCs. TEST the system for normal operation.

-> No

GO to Pinpoint Test G290075t7.

G290075t7 : CHECK THE IGNITION COIL (CYLS 1, 3, 5) MONITOR CIRCUITS
FOR SHORT TO GROUND

1. Disconnect the relevant ignition coil electrical connector(s). 2. Measure the resistance between:

Cyl 1 PI02, pin 02 (GB) and GROUND.

Cyl 3 PI03, pin 02 (GB) and GROUND.

Cyl 5 PI04, pin 02 (GB) and GROUND.

Is the resistance less than 10,000 ohms?

-> Yes

REPAIR the short to GROUND. For additional information, refer to the wiring diagrams. CLEAR the

DTCs. TEST the system for normal operation.

-> No

GO to Pinpoint Test G290075t8.

G290075t8 : CHECK THE IGNITION COIL (CYLS 2, 4, 6) MONITOR CIRCUITS
FOR HIGH RESISTANCE

1. Disconnect the relevant ignition coil electrical connector(s), (PI06 to PI08). 2. Measure the

resistance between:

Cyl 2 PI06, pin 02 (YB) and PI01, pin 132 (YB).

Cyl 4 PI07, pin 02 (YB) and PI01, pin 132 (YB).

Cyl 6 PI08, pin 02 (YB) and PI01, pin 132 (YB).

Is the resistance greater than 5 ohms?

-> Yes

REPAIR the high resistance circuit. This circuit includes the harness splice, PIS12. For additional

information, refer to the wiring diagrams. CLEAR the DTCs. TEST the system for normal operation.

-> No

GO to Pinpoint Test G290075t9.

G290075t9 : CHECK THE IGNITION COIL (CYLS 2, 4, 6) MONITOR CIRCUITS
FOR SHORT TO B+ VOLTAGE

1. Reconnect the battery negative terminal. 2. Disconnect the relevant ignition coil electrical

connector(s), (PI06 to PI08). 3. Measure the voltage between:

Cyl 2 PI06, pin 02 (YB) and GROUND.

Cyl 4 PI07, pin 02 (YB) and GROUND.

Cyl 6 PI08, pin 02 (YB) and GROUND.

Is the voltage greater than 3 volts?

-> Yes

REPAIR the short to B+ voltage. For additional information, refer to the wiring diagrams. CLEAR the

DTCs. TEST the system for normal operation.

-> No

GO to Pinpoint Test G290075t10.

G290075t10 : CHECK THE IGNITION COIL (CYLS 2, 4, AND 6) MONITOR
CIRCUITS FOR SHORT TO GROUND

1. Disconnect the relevant ignition coil electrical connector(s), (PI06 to PI08). 2. Measure the

resistance between:

Cyl 2 PI06, pin 02 (YB) and GROUND.

Cyl 4 PI07, pin 02 (YB) and GROUND.

Cyl 6 PI08, pin 02 (YB) and GROUND.

Is the resistance less than 10,000 ohms?

-> Yes

REPAIR the short to GROUND. For additional information, refer to the wiring diagrams. CLEAR the

DTCs. TEST the system for normal operation.

-> No

Contact dealer technical support for advice on possible ECM failure.

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PINPOINT TEST G290075p2 : CHECK
SPARK PLUG RESISTANCE

G290075t11 : CHECK SPARK PLUG RESISTANCE

1. Remove the suspect spark plug(s). 2. Measure the resistance between the spark plug center

electrode tip and the spark plug HT contact.

Is the resistance between 8,000 and 12,000 ohms? (nominal 10,000 ohms)

-> Yes

Check ignition coil and circuits. See possible sources list for misfire.

-> No

INSTALL a new spark plug. CLEAR the DTC. TEST the system for normal operation.

Engine Ignition - VIN Range: G45704-
>G99999

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.

Inspection and Verification

1 . Verify the customer concern.

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

Mechanical

Electrical

Engine oil level

Cooling system coolant level

Fuel level

Fuel contamination/grade/quality

Fuses

Wiring harness

Loose or corroded electrical connectors

Ignition coils

Sensor(s)

Engine control module (ECM)

Transmission control module (TCM)

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.

Symptom Chart

Symptom

Possible source

Action

Engine cranks, but does

not fire

Engine breather system

disconnected/restricted

Ignition system

Check the engine breather system,

Engine Emission Control - VIN Range:

G45704->G99999 For ignition system

tests, refer to pinpoint tests in this

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