Jaguar XJ (X350). Manual — part 772

pressure reading then a failure will be flagged.

A second pressure measurement is made after the requirement for AIR into the exhaust system has

expired, but continuing on from the same period of AIR pump operation, i.e. the pump is left

running, against a closed AIR switching valve. Again this pressure measurement is the average of a

one second duration of readings normalised for variations in battery voltage and atmospheric

pressure. If the system pressure measured at this time has not risen enough or has risen too much

with respect to the system pressure during normal operation of AIR then a failure will be flagged.

A final pressure reading is taken after the AIR system has been switched off to ensure the system

shuts down.

Diagnosis and testing

Engine Emission Control - VIN Range:
G00442->G45703

1 . Verify the customer concern by operating the system.

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

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 concern is not visually evident, refer to the Symptom Chart.

Diagnostic Trouble Code (DTC) P0400 indicates exhaust gas recirculation (EGR) system flow

malfunction.

Possible Source(s):

Exhaust manifold to EGR valve pipe tube blocked.

Exhaust manifold to EGR valve pipe tube cracked.

EGR valve stuck closed.

EGR valve stuck open.

EGR valve loose.

Fuse 37 in the front power distribution box (FPDB).

Relay 5 in the FPDB

Electrical harness.

Electrical connector(s)

Action(s) to take:

GO to Pinpoint Test A.

Diagnostic Trouble Code (DTC) P0405 indicates exhaust gas recirculation (EGR) valve malfunction,

short to battery/12volts (V).

Possible Source(s):

Electrical harness.

Electrical connector(s).

Engine control module (ECM).

EGR valve.

Action(s) to take:

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GO to Pinpoint Test B.

Diagnostic Trouble Code (DTC) P0406 indicates exhaust gas recirculation (EGR) valve malfunction,

short to ground/open circuit.

Possible Source(s):

Electrical harness.

Electrical connector(s).

ECM.

EGR valve.

Action(s) to take:

GO to Pinpoint Test C.

PINPOINT TEST G187746p1 : Diagnostic
Trouble Code (DTC) P0400 indicates
exhaust gas recirculation (EGR) system
flow malfunction.

G187746t24 : CHECK EGR VALVE FOR CORRECT FITMENT TO INTAKE
MANIFOLD

1. Check the EGR valve retaining bolts for correct torque.

Exhaust Gas Recirculation (EGR) Valve (17.45.01)

Was the EGR valve fitted correctly?

-> Yes

GO to Pinpoint Test G187746t2.

-> No

GO to Pinpoint Test G187746t1.

G187746t1 : CHECK EXHAUST GAS RECIRCULATION (EGR) VALVE TO
MANIFOLD/INTAKE ELBOW GASKET FOR CORRECT SEAL

1. Visually inspect the gasket for external damage.

Is the gasket damaged?

-> Yes

INSTALL a new gasket, make sure valve is seated correctly and retaining bolts installed to the correct

torque.

Exhaust Gas Recirculation (EGR) Valve (17.45.01) CLEAR DTC. To validate fix drive vehicle between 30

mph (48 kph) and 40 mph (64 kph). Allow vehicle to idle for 2 minutes.

-> No

GO to Pinpoint Test G187746t2.

G187746t2 : CHECK FOR EXHAUST MANIFOLD TO EGR VALVE TUBE FOR
DAMAGE or BLOCKAGES

1. Visually inspect the exhaust manifold to EGR valve tube.

Is the tube damaged or blocked?

-> Yes

If the tube is damaged INSTALL a new tube.

Exhaust Manifold to Exhaust Gas Recirculation (EGR) Valve Tube (17.45.11) CLEAR the DTC. To

validate fix drive vehicle between 30 mph (48 kph) and 40 mph (64 kph). Allow vehicle to idle for 2

minutes. If the tube is blocked, unblock the tube. CLEAR DTC. TEST the system for normal operation.

-> No

GO to Pinpoint Test G187746t3.

G187746t3 : CHECK FOR POWER SUPPLY TO EGR VALVE

1. Disconnect EGR valve electrical connector PI 15 2. TURN ignition switch to the ON position 3.

MEASURE the voltage at PI 15 pin 2 (GU)

Is the voltage less than 10 volts

-> Yes

GO to Pinpoint Test G187746t4.

-> No

GO to Pinpoint Test G187746t4.

G187746t4 : CHECK FUSE 37 IN THE FRONT POWER DISTRIBUTION BOX
(FPDB)

1. Check the fuse.

Is the fuse ok?

-> Yes

GO to Pinpoint Test G187746t6.

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