EMISSION CONTROL - V8
17-2-14 DESCRIPTION AND OPERATION
The heated oxygen sensor is screwed into threaded mountings welded into the top of the front exhaust pipes at
suitable locations. They are used to detect the level of residual oxygen in the exhaust gas to provide an instantaneous
indication of whether combustion is complete. By positioning sensors in the stream of exhaust gases from each
separate bank of the exhaust manifold, the engine management system is better able to control the fuelling
requirements on each bank independently of the other, so allowing much closer control of the air:fuel ratio and
optimising catalytic converter efficiency.
Two pre-catalytic converter heated oxygen sensors are mounted in the front pipes for monitoring the oxygen content
of the exhaust gas. NAS models also have two additional post-catalytic converter heated oxygen sensors in the
exhaust front pipe.
CAUTION: HO2 sensors are easily damaged by dropping, over torquing, excessive heat or contamination.
Care must be taken not to damage the sensor housing or tip.
The oxygen sensors consist of a ceramic body (Galvanic cell) which is a practically pure oxygen-ion conductor made
from a mixed oxide of zirconium and yttrium. The ceramic is then coated with gas-permeable platinum, which when
heated to a sufficiently high temperature (≥ 350° C) generates a voltage which is proportional to the oxygen content
in the exhaust gas stream.
The heated oxygen sensor is protected by an outer tube with a restricted flow opening to prevent the sensor's
ceramics from being cooled by low temperature exhaust gases at start up. The post-catalytic sensors have improved
signal quality, but a slower response rate.
The pre-catalytic and post-catalytic converter sensors are not interchangeable, and although it is possible to mount
them in transposed positions, their harness connections are of different gender and colour. It is important not to
confuse the sensor signal pins; the signal pins are gold plated, whilst the heater supply pins are tinned,
mixing them up will cause contamination and adversely affect system performance.
Each of the heated oxygen sensors have a four pin connector with the following wiring details:
lSensor signal ground (grey wire – connects to engine management ECM)
lSensor signal (black wire – connects to engine management ECM)
lHeater drive (white wire – connects to engine management ECM)
lHeater supply (white wire – connects to fuse 2, underbonnet fuse box)
The ECM connector pins for exhaust emission control are listed in the following table:
ECM Connector 2 (C635) pin-out details for exhaust emission control system
The heated oxygen sensors should be treated with extreme care, since the ceramic material within them can be easily
cracked if dropped, banged or over-torqued; the sensors should be torqued to the recommended values indicated in
the repair procedures. Apply anti-seize compound to the sensor's threads when refitting.
WARNING: Some types of anti-seize compound used in service are a health hazard. Avoid skin contact.
WARNING: To prevent personal injury from a hot exhaust system, do not attempt to disconnect any
components until the exhaust system has cooled down.
CAUTION: Do not allow anti-seize compound to come into contact with tip of sensor or enter exhaust system.
NOTE: A new HO2 sensor is supplied pre-treated with anti-seize compound.
Pin Number Function Signal Type Control
2-01 Post-cat sensor heater (RH) - NAS only Output, Drive PWM, 12 - 0V
2-07 Post-cat sensor heater (LH) - NAS only Output, Drive PWM, 12 - 0V
2-08 Post-cat sensor (RH) - NAS only Ground, Signal 0V
2-09 Pre-cat sensor (LH) Ground, Signal 0V
2-10 Pre-cat sensor (RH) Ground, Signal 0V
2-11 Post-cat sensor (LH) - NAS only Ground, Signal 0V
2-13 Pre-cat sensor heater (RH) Output, Drive PWM, 12 - 0V
2-14 Post-cat sensor (RH) - NAS only Input, Signal Analogue, 0 - 1V
2-15 Pre-cat sensor (LH) Input, Signal Analogue, 0 - 1V
2-16 Pre-cat sensor (RH) Input, Signal Analogue, 0 - 1V
2-17 Post-cat sensor (LH) - NAS only Input, Signal Analogue, 0 - 1V
2-19 Pre-cat sensor heater (LH) Output, Drive PWM, 12 - 0V
SEATS
DESCRIPTION AND OPERATION 76-5-1
SEATS DESCRIPTION AND OPERAT ION
Electric seat component location
RHD shown, LHD similar
1BCU
2Drivers door switch
3Power relay
4Satellite fuse box
5Switch pack
6Fore/aft motor7Cushion front up/down motor
8Cushion rear up/down motor
9Squab fore/aft motor
10Lumbar support bladder
11Lumbar pump
IN CAR ENTERTAINMENT
86-6-28 DESCRIPTION AND OPERATION
Fault Finding
The following table details potential faults, possible causes and rectification suggestions.
Fault Possible Cause Rectification
System fails to power up Missing or blown fuse Check both fuses in passenger compartment fusebox
Battery voltage too low or too high Voltage protection system may be active. Check battery
voltage output
Faulty connections Check all DVD harness connections for security and
correct location of pins
Faulty overhead console Replace overhead console
Damaged DVD harness Check all DVD harnesses for damage and repair or
replace as required
Faulty noise filter connection Check power supply wires into and out of the noise filter
on the CD switch box
No picture or sound Missing or blown fuse Check both fuses in passenger compartment fusebox
Low or high battery voltage Check battery voltage output
Vehicle interior is too hot or too
coldAllow vehicle interior to warm up or cool down before
switching on the system
DVD parental rating system is
preventing DVD playRefer to DVD System Owner's Manual and check the
parental control rating setting
LCD monitor is pushed too far
forwardReturn LCD monitor to an angle for normal viewing
Good picture, no sound Volume setting on audio head unit
too lowCheck and adjust head unit volume control
Headphone not connected, faulty
headphone or headphone volume
control incorrectly setEnsure headphone is correctly connected.
Check headphone for correct operation.
check headphone remote volume control setting.
Faulty connections Check all DVD harness connections for security and
correct location of pins
CD switch box or harness fault Check all harnesses to and from the CD switch box. If
harnesses OK, replace CD switch
Faulty overhead console Replace overhead console
Good sound, poor or no
pictureVehicle interior is too cold Allow the vehicle interior to warm up before switching on
the system
Source mode set incorrectly Press the 'Source' button on the remote handset to set
the correct operating mode
Faulty overhead console Replace overhead console
Remote control handset
does not functionCheck batteries in remote control
handsetReplace batteries with new batteries
Ensure that infra-red sensor on
overhead console is not
obstructedLower LCD monitor and check that sensor is not
obstructed or dirty
Status LED on overhead
console is flashingVehicle interior is too hot allow vehicle interior to cool down before switching on
the system
Audio through vehicle
speakers but not through
wired headphonesFaulty headphones Check headphone for correct operation.
Faulty overhead console Replace overhead console
Audio through vehicle
speakers but not through
wireless headphonesFaulty batteries in wireless
headphonesReplace batteries
Faulty headphones Test with known operational headphones and replace
headphones if necessary
Faulty RF transmitter or connector Replace overhead console
Faulty overhead console Replace overhead console
IN CAR ENTERTAINMENT
DESCRIPTION AND OPERATION 86-6-29
Audio through headphones
but not through vehicle
speakersFaulty connections a CD switch
boxCheck DVD harnesses and connectors into and out of
the CD switch box
CD switch box internal switches
incorrectly setCheck internal switches on CD switch box for correct
settings for vehicle audio head unit
Faulty CD autochanger (if fitted) Check and if necessary replace CD autochanger
Faulty CD switch box Check and replace CD switch box
Audio CD autochanger does
not operateMissing or blown fuse Check both fuses in passenger compartment fusebox
DVD system speaker setting
incorrectPress speaker button on overhead console or remote
control handset to switch from DVD audio to head unit
CD audio
Faulty audio connections Check all connectors from the audio head unit to the CD
autochanger
Faulty CD autochanger Replace CD autochanger
Faulty CD switch box connections Check CD switch box connectors for security and
correct location of pins
Faulty CD switch box Replace CD switch box
Faulty main DVD harness Check main DVD harness for damage and repair or
replace as necessary
Faulty overhead console Replace overhead console
Overhead console DVD
player will not accept discsMissing or blown fuse Check both fuses in passenger compartment fusebox
Faulty or damaged disc check disc and try a known operational disc
Faulty overhead console Replace overhead console