Jaguar XJ (X350). Manual — part 1004

-> Yes

GO to Pinpoint Test G549822t76.

-> No

GO to Pinpoint Test G549822t74.

G549822t74 : CHECK THE IAT SENSOR RETURN CIRCUIT FOR SHORT
CIRCUIT TO POWER

1. Measure the resistance between:

EC67, harness side

Battery

Pin 03

Positive terminal

Is the resistance greater than 100 Kohms?

-> Yes

GO to Pinpoint Test G549822t75.

-> No

GO to Pinpoint Test G549822t83.

G549822t75 : CHECK THE IAT SENSOR TO ECM RETURN CIRCUIT FOR HIGH
RESISTANCE

1. Key off. 2. Disconnect the ECM connector, EC66. 3. Measure the resistance between:

EC67, harness side EC66, harness side

Pin 03

Pin L4

Is the resistance less than 10 ohms?

-> Yes

Suspect: - ECM connector - ECM

-> No

REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. Clear any

DTCs, test the system for normal operation.

G549822t76 : CHECK FOR POWER TO THE IAT SENSOR

1. Key on, engine off. 2. Measure the voltage between:

EC67, harness side

Battery

Pin 02

Negative terminal

Is the voltage between 4.8 volts - 5.2 volts?

-> Yes

GO to Pinpoint Test G549822t80.

-> No

GO to Pinpoint Test G549822t77.

G549822t77 : CHECK THE IAT SIGNAL CIRCUIT FOR SHORT CIRCUIT TO
GROUND

1. Measure the resistance between:

EC67, harness side

Battery

Pin 02

Negative terminal

Is the resistance greater than 100 Kohms?

-> Yes

GO to Pinpoint Test G549822t78.

-> No

GO to Pinpoint Test G549822t81.

G549822t78 : CHECK THE IAT SIGNAL CIRCUIT FOR SHORT CIRCUIT TO
POWER

1. Key on, engine off. 2. Measure the resistance between:

EC67, harness side

Battery

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Pin 02

Positive terminal

Is the resistance greater than 100 Kohms?

-> Yes

GO to Pinpoint Test G549822t79.

-> No

GO to Pinpoint Test G549822t84.

G549822t79 : CHECK THE IAT SIGNAL CIRCUIT FOR HIGH RESISTANCE

1. Measure the resistance between:

EC67, harness side EC66, harness side

Pin 02

Pin F1

Is the resistance less than 10 ohms?

-> Yes

Suspect: - ECM connector - ECM

-> No

REPAIR the high resistance circuit. For additional information, refer to the wiring diagrams. Clear any

DTCs, test the system for normal operation.

G549822t80 : CHECK THE COMPONENT RESISTANCE

1. Measure the resistance between:

EC67, component side EC67, component side

Pin 02

Pin 03

Is the resistance between 150 ohms - 15 Kohms?

-> Yes

An intermittent fault may be present in the wiring harness. Visually check for chaffed wires or other

physical damage to the harness. If no fault is found in the circuit, suspect the following

component(s): - MAF1 connector - MAF1 sensor - ECM connector - ECM

-> No

INSTALL a new MAF1 sensor.

Mass Air Flow (MAF) Sensor (18.30.15)

G549822t81 : CHECK THE IAT SIGNAL AND RETURN CIRCUITS FOR SHORT
CIRCUIT TO EACH OTHER

1. Key off. 2. Disconnect the ECM connector, EC66. 3. Key on, engine off. 4. Measure the resistance

between:

EC67, harness side EC67, harness side

Pin 02

Pin 03

Is the resistance greater than 100 Kohms?

-> Yes

GO to Pinpoint Test G549822t82.

-> No

REPAIR the short circuit. For additional information, refer to the wiring diagrams. Clear any DTCs, test

the system for normal operation.

G549822t82 : CHECK WHETHER THE SHORT CIRCUIT TO GROUND IS IN THE
HARNESS OR THE MODULE

1. Measure the resistance between:

EC67, harness side

Battery

Pin 02

Negative terminal

Is the resistance greater than 100 Kohms?

-> Yes

Suspect: - ECM

-> No

REPAIR the short circuit. For additional information, refer to the wiring diagrams. Clear any DTCs, test

the system for normal operation.

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