Jaguar XJ (X350). Service manual — part 1076

Description and operation

Exhaust System

Item

Part Number

Description

1

Catalytic converters

2

Diesel particulate filter

3

Front muffler

4

Muffler and tailpipes

Item

Part Number

Description

1

Diesel particulate filter differential pressure sensor

The exhaust system for various engines are of similar design but utilize different internal elements to

achieve a distinct exhaust note for each variant.

Catalytic Converters

The catalytic converters are of a monolithic structure and are coated in platinum. The platinum

coating is used to control the emissions of hydrocarbons (HC), carbon monoxide (CO) and oxides of

nitrogen (NOx) and to convert them into less harmful products for example carbon dioxide (CO)

nitrogen (N) and water (HO).

The catalytic converters are connected to the turbocharger by a three nut flange and is sealed by a

gasket. Exhaust jointing compound must not be applied to these joints due to the possibility of

catalytic converter contamination. Avoid allowing any foreign particles of debris into the catalytic

downpipe as this can result in damage to the catalytic converter.

Diesel Particulate Filter

In order to meet strict Euro IV emission limits there is now a stipulation to reduce gaseous and

particulate emissions greatly. The primary component within the exhaust system of the diesel is the

diesel particulate filter. The diesel particulate filter uses new filter technology based on a combined

filter and oxidation catalytic converter to store, and when conditions allow, destroy the particulates.

The diesel particulate filter is of a silicon carbide filter construction. It has an additional wash coating

on its filter surface of platinum and other active components which are used in the manufacture of

oxidation catalytic converters. The exhaust gasses pass through the filter, leaving the particulates

behind that are too big to pass through the filters pores. With engine management intervention and

the catalytic coating this will promote particulate combustion and oxidation of carbon monoxide (CO)

and hydrocarbon (HC) emissions. By carrying out this process, this will regenerate the diesel

particulate filter to prevent increased back-pressure and the possibility of a completely blocked filter.

Diesel particulate filter differential pressure sensor

The diesel particulate filter differential pressure sensor monitors the differential pressure in the

pipeline, upstream and downstream of the diesel particulate filter. The filtering of the particulates

will lead to a greater resistance to the exhaust gas flow through the diesel particulate filter. This

leads to a greater pressure difference upstream and downstream of the diesel particulate filter. The

diesel particulate filter differential pressure sensor is a membrane sensor with strain resistances. The

strain resistances change depending on the pressure difference. This leads to a change in the signal

voltage. This signal is one of the parameters required for the strategy of the regeneration of the

diesel particulate filter.

Exhaust System – Armoured

Muffler and Tailpipe

The exhaust system is modified so that the engine cannot be stalled by stopping the flow of exhaust

system emissions. Unique muffler and tailpipes are installed to the vehicle for this purpose.

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Diagnosis and testing

Exhaust System

Overview

2006MY sees the introduction of diesel to X350 and is accompanied by a diesel particulate filter

(DPF) system to comply with strict stage four emissions requirements. The engine management

system (EMS) makes use of 7-digit diagnostic trouble codes (DTCs) rather than 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.

For information on the operation of the system,

Exhaust System

Inspection and Verification

1 . Verify the customer concern.

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

Mechanical

Electrical

Leaks

Metal fatigue

Pipes, mufflers and catalytic converters

Diesel particulate filter (DPF)

DPF differential pressure sensor tubes

Joints

Mountings

Clearance around components

Battery charge and condition

Wiring harness

Electrical connector(s)

5 volt sensor supply

Sensor(s)

Engine control module (ECM)

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, or the symptom chart if no DTCs are set.

Symptom Chart

Symptom

Possible source

Action

Noisy or

leaking

exhaust

Exhaust system/components

Install new components as necessary.

Exhaust System - 2.7L V6 - TdV6

Lack of power

Air intake system fault

Diesel particulate fliter (DPF)

blocked/restricted

Restricted exhaust system

Low fuel pressure

Exhaust gas recirculation

(EGR) valve(s) fault

Turbocharger(s) fault

Check the air intake system,

Intake Air Distribution and Filtering Check for a

blocked DPF or catalytic converter, install new

components as necessary.

Diesel Particulate Filter (DPF) or

Catalytic Converter - 2.7L V6 - TdV6 (17.50.05)

Check the fuel pressure,

Fuel Charging and Controls For EGR tests,

Engine Emission Control For turbocharger tests,

Turbocharger

DTC index

NOTE:

Generic scan tools may not read the codes listed, or may read only 5-digit codes. Match the 5

digits from the scan tool to the first 5 digits of the 7-digit code listed to identify the fault (the last

2 digits give extra information read by the manufacturer-approved diagnostic system).

NOTE:

For a full list of powertrain DTCs,

Electronic Engine Controls

P024B00

Diesel particulate filter

(DPF) temperature

sensor - catalyst

downstream circuit

range/performance

(right hand bank)

Temperature sensor -

catalyst
downstream
circuit: high
resistance

Temperature sensor -

catalyst
downstream
circuit: short

For temperature sensor - catalyst

downstream circuit tests, GO to

Pinpoint Test G552286p2.

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