1999 LAND ROVER DISCOVERY heater

CONTENTS
CONTENTS 23
BODY SEALING MATERIALS ................................................................. 77-3-1
MATERIALS AND APPLICATIONS
Materials applications ..................................................................................................................... 77-3-1
Approved materials ......................................................................................................................... 77-3-2
Application equipment..................................................................................................................... 77-3-4
CORROSION PREVENTION AND SEALING .......................................... 77-4-1
CORROSION PREVENTION
Cavity wax treatment areas and injection holes - 'A' post and sill ................................................... 77-4-1
Cavity wax treatment area and injection hole - fuel filler neck ........................................................ 77-4-2
Cavity wax treatment areas and injection holes - rear cross member ............................................ 77-4-3
Cavity wax treatment areas and injection holes - front door, rear door and tail door ...................... 77-4-4
Corrosion prevention....................................................................................................................... 77-4-6
SEALING
Body Sealing ................................................................................................................................... 77-4-9
Water leaks ..................................................................................................................................... 77-4-22
PAINTING ................................................................................................ 77-5-1
PROCEDURES
Panel preparation............................................................................................................................ 77-5-1
Paint preparation............................................................................................................................. 77-5-2
HEATING AND VENTILATION................................................................. 80-1
DESCRIPTION AND OPERATION
Heating and ventilation component layout ...................................................................................... 80-1
Fuel burning heater component layout ........................................................................................... 80-2
Description ...................................................................................................................................... 80-3
Operation ........................................................................................................................................ 80-13
REPAIRS
Heater control and fan switch ....................................................................................................... 80-15
Cables - heater control .................................................................................................................. 80-15
Servo - recirculation flap ............................................................................................................... 80-17
Switch - recirculation control ......................................................................................................... 80-18
Servo - air distribution control ........................................................................................................ 80-19
Servo - air temperature control ....................................................................................................... 80-20
Plenum Air Intake ........................................................................................................................... 80-21
Heater assembly - models without air conditioning ......................................................................... 80-22
Heater assembly - models with air conditioning .............................................................................. 80-24
Blower assembly ............................................................................................................................ 80-26
Motor - blower ............................................................................................................................. 80-27
Resistor pack - power resistor A/C ............................................................................................... 80-28
Heater matrix ................................................................................................................................ 80-29
Pipe - Heater - Feed ...................................................................................................................... 80-29
Pipe - Heater - Return .................................................................................................................... 80-30
Fuel burning heater - (FBH) - Td5................................................................................................... 80-31

INTRODUCTION
01-3
Abbreviations and Symbols
A Amperes
AAP Ambient Air Pressure
ABDC After Bottom Dead Centre
ABS Anti-Lock Brake System
ac Alternating current
A/C Air Conditioning
ACE Active Cornering Enhancement
ACEA Association of Constructors of
European Automobiles
AFR Air Fuel Ratio
AP Ambient Pressure
ASC Anti-shunt Control
ATC Air Temperature Control
ATDC After Top Dead Centre
BBDC Before Bottom Dead Centre
BBUS Battery Backed Up Sounder
BCU Body Control Unit
BDC Bottom Dead Centre
bhp Brake Horse Power
BP Boost Pressure
BPP Brake Pedal Position
BS British Standard
BTDC Before Top Dead Centre
C Celsius
CAN Controller Area Network
CD Compact Disc
CDC Centre Differential Control
CDL Central Door Locking
CD - ROM Compact Disc - Read Only
Memory
CFC Chlorofluorocarbon
CHMSL Centre High Mounted Stop Lamp
CKP Crankshaft Position
CLV Calculated Load Value
cm Centimetre
cm
2Square centimetre
cm3Cubic centimetre
CMP Camshaft Position
CPP Clutch Pedal Position
CO Carbon Monoxide
CO
2Carbon Dioxide
CR Common Rail
CVS Canister Vent Solenoid
deg. Degree, angle or temperature
dia. Diameter
DIN Deutsche Industrie Normen
(German Industrial Standards)
dc Direct current
DCV Directional Control Valve
DOHC Double Overhead Camshaft
DTI Dial Test Indicator
DFM Dual Mass Flywheel
DVD Digital Versatile Disc
EACV Electronic Air Control Valve EAT Electronic Automatic
Transmission
EBD Electronic Brake pressure
Distribution
ECD European Community Directive
ECM Engine Control Module
ECT Engine Coolant Temperature
ECU Electronic Control Unit
EDC Electronic Diesel Control
EEPROM Electronic Erasable
Programmable Read Only
Memory
EGR Exhaust Gas Recirculation
EKA Emergency Key Access
EN European Norm
EOBD European On Board Diagnostics
ETC Electronic Traction Control
EUI Electronic Unit Injector
EVAP Evaporative Emission
EVR Electronic Vacuum Regulator
F Fahrenheit
FBH Fuel Burning Heater
FIP Fuel Injection Pump
FTC Fast Throttle Control
g Gramme or Gravity
hHour
hc High compression
HC Hydro Carbons
HDC Hill Descent Control
HDPE High Density Polyethylene
HFS Heated Front Screen
Hg Mercury
HO2S Heated Oxygen Sensor
HMW High Molecular Weight
HRW Heated Rear Window
ht/HT High tension
IACV Idle Air Control Valve
IAT Intake Air Temperature
ICE In-Car Entertainment
i.dia. Internal diameter
IDM Intelligent Driver Module
in3Cubic inch
ILT Inlet Throttle
ISO International Organisation for
Standardisation
k Thousand
kg Kilogramme
km Kilometre
km/h Kilometres per hour
kPa KiloPascal
KS Knock Sensor
lLitre
lbf.in Pounds force inches
lbf/in
2Pounds per square inch
lbf.ft Pounds force feet

TORQUE WRENCH SETTINGS
06-2
Engine Td5
TORQUE DESCRIPTION METRIC IMPERIAL
ACE pump bolts25 Nm (18 lbf.ft)
A/C compressor bolts 25 Nm (18 lbf.ft)
Alternator support bracket to cylinder head bolts 25 Nm (18 lbf.ft)
Alternator/vacuum pump oil feed pipe union 10 Nm (7 lbf.ft)
Camshaft cover to camshaft carrier bolts 10 Nm (7 lbf.ft)
Camshaft sprocket to camshaft bolts 37 Nm (27 lbf.ft)
Centrifuge cover bolts 10 Nm (7 lbf.ft)
Centrifuge oil drain pipe to sump bolts (or nuts) 10 Nm (7 lbf.ft)
Centrifuge to oil drain pipe bolts 10 Nm (7 lbf.ft)
Centrifuge to oil cooler housing bolts 25 Nm (18 lbf.ft)
CKP sensor bolt10 Nm (7 lbf.ft)
Coolant pipe bolt50 Nm (37 lbf.ft)
Connecting rod bolts, then a further 80°20 Nm (15 lbf.ft)
Crankshaft pulley bolt 460 Nm (340 lbf.ft)
Crankshaft pulley TV damper bolts 80 Nm (59 lbf.ft)
Crankshaft rear oil seal housing bolts 10 Nm (7 lbf.ft)
Cylinder head bolts initial tighten 30 Nm (22 lbf.ft)
Cylinder head bolts final tighten, then a further 90°, then a further 180° and finally a
further 45°65 Nm (48 lbf.ft)
Dipstick tube to camshaft carrier bolt 10 Nm (7 lbf.ft)
Drive plate (automatic transmission) to crankshaft bolts 115 Nm (85 lbf.ft)
EGR pipe clamp to cylinder head bolt - if fitted 25 Nm (18 lbf.ft)
EGR pipe Allen screws 10 Nm (7 lbf.ft)
Engine mounting (front) to cylinder block bolts 48 Nm (35 lbf.ft)
Engine mounting (front) to chassis nuts 85 Nm (63 lbf.ft)
Engine mounting bracket (rear, LH & RH) to gearbox bolts 85 Nm (63 lbf.ft)
Engine mounting bracket (rear, LH & RH) nuts 45 Nm (33 lbf.ft)
Flywheel to crankshaft (manual transmission) bolts, then a further 90°40 Nm (30 lbf.ft)
Front crossmember bolts 26 Nm (20 lbf.ft)
Fuel connector block bolts 25 Nm (18 lbf.ft)
Fuel cooler to inlet manifold bolts 25 Nm (18 lbf.ft)
Gearbox housing to engine bolts 50 Nm (37 lbf.ft)
Heater pipe to cylinder head bolts 25 Nm (18 lbf.ft)
Main bearing cap bolts then a further 90°33 Nm (24 lbf.ft)
Oil cooler housing to cylinder block bolts 25 Nm (18 lbf.ft)
Oil cooler pipe clip bolts 10 Nm (7 lbf.ft)
Oil filter adaptor housing to oil cooler housing bolts 25 Nm (18 lbf.ft)
Oil pick-up strainer Torx screws + 10 Nm (7 lbf.ft)
Oil pressure switch 15 Nm (11 lbf.ft)
Oil pump drive sprocket bolt + 25 Nm (18 lbf.ft)
Oil pump pressure relief valve plug + 25 Nm (18 lbf.ft)
Oil pump and stiffener assembly to cylinder block bolts 13 Nm (10 lbf.ft)
Oil sump to cylinder block bolts 25 Nm (18 lbf.ft)
Oil sump to gearbox bell housing bolts 13 Nm (10 lbf.ft)
PAS pump bracket bolts 27 Nm (20 lbf.ft)
PAS pump pulley bolts 27 Nm (20 lbf.ft)
Rocker arm adjusting screw locknuts 16 Nm (12 lbf.ft)

TORQUE WRENCH SETTINGS
06-20
Heating and air conditioning
Wipers and washers
TORQUE DESCRIPTION METRIC IMPERIAL
Heater assembly16 Nm (12 lbf.ft)
Compressor bolts22 Nm (16 lbf.ft)
Blower motor19 Nm (14 lbf.ft)
Compressor to mounting bracket bolts 25 Nm (18 lbf.ft)
A/C pipes to compressor bolts 10 Nm (7 lbf.ft)
Condenser pipe bolt 5 Nm (3.7 lbf.ft)
Receiver drier to bracket bolts 5 Nm (3.7 lbf.ft)
Adaptor block to receiver drier bolt 5 Nm (3.7 lbf.ft)
Evaporator pipe bolts 5 Nm (3.7 lbf.ft)
Dual pressure switch to receiver drier 10 Nm (7 lbf.ft)
Air conditioning pipes to receiver drier bolts 5 Nm (3.7 lbf.ft)
TX valve pressure pipe union 22 Nm (16 lbf.ft)
Evaporator pipe to TXV valve 32 Nm (24 lbf.ft)
Evaporator assembly to body bolts 16 Nm (12 lbf.ft)
High and low pressure pipe, bolts 10 Nm (7 lbf.ft)
Fuel burning heater Torx bolts 25 Nm (18 lbf.ft)
TORQUE DESCRIPTION METRIC IMPERIAL
Link to motor spindle 7 Nm (5.2 lbf.ft)
Front motor assembly 2.5 Nm (1.8 lbf.ft)
Spindle nut 3 Nm (2.2 lbf.ft)
Wiper arm nut13 Nm (10 lbf.ft)

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

EMISSION CONTROL - V8
DESCRIPTION AND OPERATION 17-2-35
Exhaust Emission Control Operation
The oxygen content of the exhaust gas is monitored by heated oxygen sensors using either a four sensor (NAS only)
or two sensor setup, dependent on market destination and legislative requirements. Signals from the heated oxygen
sensors are input to the engine management ECM which correspond to the level of oxygen detected in the exhaust
gas. From ECM analysis of the data, necessary changes to the air:fuel mixture and ignition timing can be made to
bring the emission levels back within acceptable limits under all operating conditions.
Changes to the air:fuel ratio are needed when the engine is operating under particular conditions such as cold starting,
idle, cruise, full throttle or altitude. In order to maintain an optimum air:fuel ratio for differing conditions, the engine
management control system uses sensors to determine data which enable it to select the ideal ratio by increasing or
decreasing the air to fuel ratio. Improved fuel economy can be arranged by increasing the quantity of air to fuel to
create a lean mixture during part-throttle conditions, however lean running conditions are not employed on closed loop
systems where the maximum is λ = 1. Improved performance can be established by supplying a higher proportion of
fuel to create a rich mixture during idle and full-throttle operation. Rich running at wide open throttle (WOT) for
performance and at high load conditions helps to keep the exhaust temperature down to protect the catalyst and
exhaust valves.
The voltage of the heated oxygen sensors at λ = 1 is between 450 and 500 mV. The voltage decreases to 100 to 500
mV if there is an increase in oxygen content (λ > 1) indicating a lean mixture. The voltage increases to 500 to 1000
mV if there is a decrease in oxygen content (λ < 1), signifying a rich mixture.
The heated oxygen sensor needs to operate at high temperatures in order to function correctly (≥ 350° C). To achieve
this the sensors are fitted with heater elements which are controlled by a pulse width modulated (PWM) signal from
the engine management ECM. The heater element warms the sensor's ceramic layer from the inside so that the
sensor is hot enough for operation. The heater elements are supplied with current immediately following engine start
and are ready for closed loop control within about 20 to 30 seconds (longer at cold ambient temperatures less than
0°C (32°F)). Heating is also necessary during low load conditions when the temperature of the exhaust gases is
insufficient to maintain the required sensor temperatures. The maximum tip temperature is 930° C.
A non-functioning heater element will delay the sensor's readiness for closed loop control and influences emissions.
A diagnostic routine is utilised to measure both sensor heater current and the heater supply voltage so its resistance
can be calculated. The function is active once per drive cycle, as long as the heater has been switched on for a pre-
defined period and the current has stabilised. The PWM duty cycle is carefully controlled to prevent thermal shock to
cold sensors.
The heated oxygen sensors age with mileage, causing an increase in the response time to switch from rich to lean
and lean to rich. This increase in response time influences the closed loop control and leads to progressively
increased emissions. The response time of the pre-catalytic converter sensors are monitored by measuring the period
of rich to lean and lean to rich switching. The ECM monitors the switching time, and if the threshold period is exceeded
(200 milliseconds), the fault will be detected and stored in the ECM as a fault code (the MIL light will be illuminated
on NAS vehicles). NAS vehicle engine calibration uses downstream sensors to compensate for aged upstream
sensors, thereby maintaining low emissions.
Diagnosis of electrical faults is continuously monitored for both the pre-catalytic converter sensors and the post-
catalytic converter sensors (NAS only). This is achieved by checking the signal against maximum and minimum
threshold for open and short circuit conditions. For NAS vehicles, should the pre- and post-catalytic converters be
inadvertently transposed, the lambda signals will go to maximum but opposite extremes and the system will
automatically revert to open loop fuelling. The additional sensors for NAS vehicles provide mandatory monitoring of
the catalyst conversion efficiency and long term fuelling adaptations.
Note that some markets do not legislate for closed loop fuelling control and in this instance no heated oxygen
sensors will be fitted to the exhaust system.

EMISSION CONTROL - V8
17-2-36 DESCRIPTION AND OPERATION
Failure of the closed loop control of the exhaust emission system may be attributable to one of the failure modes
indicated below:
lMechanical fitting & integrity of the sensor.
lSensor open circuit / disconnected.
lShort circuit to vehicle supply or ground.
lLambda ratio outside operating band.
lCrossed sensors.
lContamination from leaded fuel or other sources.
lChange in sensor characteristic.
lHarness damage.
lAir leak into exhaust system (cracked pipe / weld or loose fixings).
System failure will be indicated by the following symptoms:
lMIL light on (NAS and EU-3 only).
lDefault to open-loop fuelling for the defective cylinder bank.
lIf sensors are crossed, engine will run normally after initial start and then become progressively unstable with
one bank going to its maximum rich clamp and the other bank going to its maximum lean clamp – the system will
then revert to open-loop fuelling.
lHigh CO reading
lStrong smell of H
2S (rotten eggs)
lExcessive emissions
Fuel Metering
When the engine is cold, additional fuel has to be provided to the air:fuel mixture to assist starting. This supplementary
fuel enrichment continues until the combustion chamber has heated up sufficiently during the warm-up phase.
Under normal part-throttle operating conditions the fuel mixture is adjusted to provide minimum fuel emissions and
the air:fuel mixture is held close to the optimum ratio (λ = 1). The engine management system monitors the changing
engine and environmental conditions and uses the data to determine the exact fuelling requirements necessary to
maintain the air:fuel ratio close to the optimum value that is needed to ensure effective exhaust emission treatment
through the three-way catalytic converters.
During full-throttle operation the air:fuel mixture needs to be made rich to provide maximum torque. During
acceleration, the mixture is enriched by an amount according to engine temperature, engine speed, change in throttle
position and change in manifold pressure, to provide good acceleration response.
When the vehicle is braking or travelling downhill the fuel supply can be interrupted to reduce fuel consumption and
eliminate exhaust emissions during this period of operation.
If the vehicle is being used at altitude, a decrease in the air density will be encountered which needs to be
compensated for to prevent a rich mixture being experienced. Without compensation for altitude, there would be an
increase in exhaust emissions and problems starting, poor driveability and black smoke from the exhaust pipe. For
open loop systems, higher fuel consumption may also occur.
Exhaust Emission System Diagnostics
The engine management ECM contains an on-board diagnostics (OBD) system which performs a number of
diagnostic routines for detecting problems associated with the closed loop emission control system. The diagnostic
unit monitors ECM commands and system responses and also checks the individual sensor signals for plausibility,
these include:
lLambda ratio outside of operating band
lLambda heater diagnostic
lLambda period diagnostic
lPost-catalytic converter lambda adaptation diagnostic (NAS only)
lCatalyst monitoring diagnostic
Lambda Ratio Outside Operating Band
The system checks to ensure that the system is operating in a defined range around the stoichiometric point. If the
system determines that the upper or lower limits for the air:fuel ratio are being exceeded, the error is stored as a fault
code in the ECM diagnostic memory (the MIL light is illuminated on NAS vehicles).

EMISSION CONTROL - V8
DESCRIPTION AND OPERATION 17-2-37
Lambda Heater Diagnostic
The system determines the heater current and supply voltage so that the heater's resistance can be calculated. After
the engine has been started, the system waits for the heated oxygen sensors to warm up, then calculates the
resistance from the voltage and current measurements. If the value is found to be outside of the upper or lower
threshold values, then the fault is processed (the MIL light is illuminated on NAS vehicles).
Lambda Period Diagnostic
The pre-catalytic converter sensors are monitored. As the sensors age, the rich to lean and the lean to rich switching
delays increase, leading to increased emissions if the lambda control becomes inaccurate. If the switching period
exceeds a defined limit, the sensor fault is stored in the ECM diagnostic memory (the MIL light is illuminated on NAS
vehicles).
Post-Catalytic Converter Lambda Adaptation Diagnostic (NAS only)
On NAS vehicles the ageing effects of the pre-catalytic converter sensors are compensated for by an adaptive value
derived from the post-catalytic converter sensors. This is a long term adaption which only changes slowly. For a rich
compensation the additive value is added to the rich delay time. For a lean compensation, the adaptive value is added
to the lean delay time. The adaptive time is monitored against a defined limit, and if the limit is exceeded, the fault is
stored in the ECM's diagnostic memory and the MIL light is illuminated on the instrument pack.
Catalyst Monitoring Diagnostic
On NAS specification vehicles the catalysts are monitored both individually and simultaneously for emission pollutant
conversion efficiency. The conversion efficiency of a catalyst is monitored by measuring the oxygen storage, since
there is a direct relationship between these two factors. The closed loop lambda control fuelling oscillations produce
pulses of oxygen upstream of the catalyst, as the catalyst efficiency deteriorates its ability to store oxygen is
decreased. The amplitudes of the signals from the pre-catalytic and post-catalytic converter heated oxygen sensors
are compared. As the oxygen storage decreases, the post-catalytic converter sensor begins to follow the oscillations
of the pre-catalytic converter heated oxygen sensors. Under steady state conditions the amplitude ratio is monitored
in different speed / load sites. There are three monitoring areas, and if the amplitude ratio exceeds a threshold in all
three areas the catalyst conversion limit is exceeded; the catalyst fault is stored in the diagnostic memory and the MIL
light is illuminated on the instrument pack. There is a reduced threshold value for both catalysts monitored as a pair.
In either case, a defective catalyst requires replacement of the downpipe assembly.
In the case of a catalytic converter failure the following failure symptoms may be apparent:
lMIL light on after 2 driving cycles (NAS market only).
lHigh exhaust back pressure if catalyst partly melted.
lExcessive emissions
lStrong smell of H
2S (rotten eggs).
Oxygen sensor voltages can be monitored using TestBook/T4, the approximate output voltage from the heated
oxygen sensors with a warm engine at idle and with closed loop fuelling active are shown in the table below:
Measurement Normal catalyst Defective catalyst
Pre-catalytic heated oxygen sensors ~ 100 to 900 mV switching @ ~ 0.5
Hz~ 100 to 900 mV switching @ ~ 0.5 Hz
Post-catalytic heated oxygen sensors ~ 200 to 650 mV, static or slowly
changing~ 200 to 850 mV, changing up to same
frequency as pre-catalytic heated oxygen
sensors
Amplitude ratio (LH HO
2 sensors & RH
HO
2 sensors)<0.3 seconds >0.6 seconds (needs to be approximately
0.75 seconds for single catalyst fault)
Number of speed/load monitoring areas
exceeded (LH & RH)0 >1 (needs to be 3 for fault storage)