Jaguar XJ (X350). Manual — part 991

G549822t14 : CHECK WHETHER THE SHORT CIRCUIT TO POWER IS IN THE
HARNESS OR THE MODULE

1. Key off. 2. Disconnect the ECM connector, C101. 3. Key on, engine off. 4. Measure the resistance

between:

C34, harness side

Battery

Pin 02

Positive 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.

G549822t15 : CHECK WHETHER THE SHORT CIRCUIT TO POWER IS IN THE
HARNESS OR THE MODULE

1. Key off. 2. Disconnect the ECM connector, C101. 3. Key on, engine off. 4. Measure the resistance

between:

C34, harness side

Battery

Pin 01

Positive 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.

PINPOINT TEST G549822p2 : FUEL
TEMPERATURE SENSOR

G549822t16 : CHECK THE FUEL TEMPERATURE PID VALUE

1.

Circuit

Pin

Fuel temperature sensor - signal

01

Fuel temperature sensor - return 02

2.

Circuit

Pin

Fuel temperature sensor - signal

B2

Fuel temperature sensor - return G3

Temperature (degrees C) Temperature (degrees F) Volts

-40

-40

4.9701

-30

-22

4.9436

-20

-04

4.8983

0

32

4.7104

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20

68

4.3092

40

104

3.6210

60

140

2.7528

80

176

1.8951

100

212

1.2389

120

248

0.7947

130

266

0.6362

150

302

0.4115

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

using the Jaguar approved diagnostic system or a scan tool.

There are two PIDs accessible for the fuel temperature sensor, the actual reading PID, and another

for limp-home. The limp-home PID is a default value, so is fixed. Make sure the actual reading PID is

used.

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

-> Yes

GO to Pinpoint Test G549822t17.

-> No

GO to Pinpoint Test G549822t20.

G549822t17 : CHECK THE FUEL TEMPERATURE PID VALUE DURING WARM
UP

1. Key on, engine running. 2. Access the ECM-fuel temperature and OBDII-engine coolant

temperature PIDs using the Jaguar approved diagnostic system or a scan tool.

There are two PIDs accessible for the fuel temperature sensor, the actual reading PID, and another

for limp-home. The limp-home PID is a default value, so is fixed. Make sure the actual reading PID is

used. 3. Increase the engine speed to 2,000 rpm and monitor the fuel temperature reading, until the

engine is at full operating temperature.

Did the fuel temperature reading rise smoothly and by more than 10 degrees C (50 degrees F)?

-> 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 G549822t18.

G549822t18 : CHECK THE FUEL TEMPERATURE PID VALUE

1.

There are two PIDs accessible for the fuel temperature sensor, the actual reading PID, and another

for limp-home. The limp-home PID is a default value, so is fixed. Make sure the actual reading PID is

used.

Were there any sudden or unexpected changes in the fuel temperature readings?

-> Yes

Key off. GO to Pinpoint Test G549822t19.

-> No

GO to Pinpoint Test G549822t20.

G549822t19 : CHECK FOR AN INTERMITTENT FAULT CONDITION

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

system or a scan tool. 3. Check the fuel temperature 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 fuel temperature 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 G549822t20.

G549822t20 : CHECK THE FUEL TEMPERATURE SENSOR RETURN CIRCUIT
FOR HIGH RESISTANCE

1. Key off. 2. Disconnect the fuel temperature sensor connector, C35. 3. Key on, engine off. 4.

Measure the resistance between:

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