Jaguar XJ (X350). Manual — part 1010

C31, harness side C31, harness side

Pin 01

Pin 03

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.

PINPOINT TEST G549822p13 : INTAKE
AIR TEMPERATURE (IAT) AND
CHARGE AIR TEMPERATURE (ACT)
SENSORS

G549822t166 : CHECK THE IAT PID VALUE

1.

Circuit

Pin

Air charge temperature sensor - signal

01

Air charge temperature sensor - return 02

2.

Circuit

Pin

Intake air temperature - return L4

Intake air temperature - signal

F1

Mass air flow sensor - return

L4

Circuit

Pin

Air charge temperature sensor - signal

B1

Air charge temperature sensor - return G3

3. Make sure that the engine is cold. 4. Key on, engine off. 5. Access the ECM-Boost air temperature

PID using the Jaguar approved diagnostic system or a scan tool.

Is the IAT reading as expected for the current environmental and engine conditions?

-> Yes

GO to Pinpoint Test G549822t167.

-> No

GO to Pinpoint Test G549822t170.

G549822t167 : CHECK THE IAT PID VALUE

1. Key on, engine running. 2. Access the ECM-Boost air temperature PID using the Jaguar approved

diagnostic system or a scan tool. 3. Slowly increase the engine speed to 4,000 rpm while monitoring

the IAT reading.

Did the IAT reading rise smoothly?

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-> Yes

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

physical damage to the harness.

-> No

GO to Pinpoint Test G549822t168.

G549822t168 : CHECK FOR AN INTERMITTENT FAULT CONDITION

1.

Were there any sudden or unexpected changes in the IAT readings?

-> Yes

Key off. GO to Pinpoint Test G549822t169.

-> No

GO to Pinpoint Test G549822t170.

G549822t169 : CHECK THE IAT PID VALUE

1. Key on, engine off. 2. Access the ECM-Boost air temperature PID using the Jaguar approved

diagnostic system or a scan tool. 3. Check the IAT harness wiring and connectors for loose

connections and water ingress. Monitoring the temperature readings for sudden changes, while

handling the harness and connectors, may help in isolation of these types of fault.

Did you identify any loose connections or water ingress in the IAT harness wiring or

connectors?

-> Yes

REPAIR the fault as necessary. For additional information, refer to the wiring diagrams. Clear any

DTCs, test the system for normal operation.

-> No

GO to Pinpoint Test G549822t170.

G549822t170 : CHECK THE ACT SENSOR RETURN CIRCUIT FOR HIGH
RESISTANCE

1. Key off. 2. Disconnect the ACT sensor connector, C69. 3. Key on, engine off. 4. Measure the

resistance between:

C69, harness side

Battery

Pin 02

Negative terminal

Is the resistance less than 10 ohms?

-> Yes

GO to Pinpoint Test G549822t173.

-> No

GO to Pinpoint Test G549822t171.

G549822t171 : CHECK THE ACT SENSOR RETURN CIRCUIT FOR SHORT
CIRCUIT TO POWER

1. Measure the resistance between:

C69, harness side

Battery

Pin 02

Positive terminal

Is the resistance greater than 100 Kohms?

-> Yes

GO to Pinpoint Test G549822t172.

-> No

GO to Pinpoint Test G549822t180.

G549822t172 : CHECK THE ACT SENSOR TO ECM RETURN CIRCUIT FOR
HIGH RESISTANCE

1. Key off. 2. Disconnect the ECM connector, C101. 3. Measure the resistance between:

C69, harness side C101, harness side

Pin 02

Pin G3

Is the resistance less than 10 ohms?

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