Page 68 of 99

Spark plugs
The spark plugs should be replaced every 60,000 miles (96,000 km) under normal driving conditions. City driving or
fast highway driving may necessitate replacement sooner.
Under normal driving conditions, spark plugs require no maintenance between replacement intervals. When installing
new plugs, be sure to use the right type and to tighten them correctly. When changing the plugs, clean the terminals
and rubber seals. Also check that the suppressor connectors are in good condition. Cracked or damaged connectors
should be replaced.
pg. 114 Fuel/emissions systems
Fuel system
The fuel system is all-electronic and is microprocessor-controlled. It can continually compensate for variation in
engine load, speed and temperature to give the best economy and power. A mass air flow sensor measures the inducted
air. In this way the system can make instantaneous adjustments for changes in air temperature or density, thus always
assuring the best economy with the lowest possible exhaust emissions.
Heated oxygen sensor(s)
This is an emission control system designed to reduce emissions and improve fuel economy. The heated oxygen sensor
monitors the composition of the exhaust gases leaving the engine. The exhaust gas analysis is fed into an electronic
module. This adjusts the air-fuel ratio to provide optimum conditions for combustion and efficient reduction of the
three major pollutants (hydrocarbons, carbon monoxide and oxides of nitrogen (NOx)) by a three-ways catalytic
converter.
Crankcase ventilation
Crankcase ventilation
The engine is provided with positive crankcase ventilation which prevents crankcase gases from being released into the
atmosphere. Instead, the crankcase gases are admitted to the intake manifold and cylinders.
Evaporative control system
The car is equipped with an evaporative control system which prevents gasoline vapor from being released into the
atmosphere.
The system consists of a fuel tank with filler pipe and cap, a rollover valve, a Fill Limit Vent Valve (FLVV), vapor
vent lines, a charcoal canister, a purge line, a purge control valve and engine connections.
In addition, there is a pressure sensor connected to the fuel tank and a filter -protected Canister Close Valve (CCV) on
ProCarManuals.com
Page 90 of 99
2 0 0 4
VOLVO C70
INDEX
pg. 193 - 195 Index
A
ABS 17
Air conditioning35
Air filter - engine113
Air mix33
Air vents33
Airbag (SIPS)8
Airbag (SRS)4
Alarm45
Ambient temperature sensor25
Anti-lock Brake System (ABS)17,74
Antifreeze77
Ashtrays31
Audio systems
-General information186
-SC-813134
-SC-816147
-SC-900/01163
Automatic daytime running24
Automatic transmission66,129
-Kickdown67
Automatic transmission fluid126
B
Battery77
,130
Battery drain - avoiding57
Battery maintenance122
Booster cushion12
Brake failure warning light17, 18
Brake fluid118,126
Brake fluid warning light28
Brake system74, 75
Brake warning light17
ProCarManuals.com
Page 93 of 99
Hood54
I
Ignition switch21
Immobilizer (start inhibitor)43
Instrument illumination22
Instruments14, 15
J
Jack56
, 86
Jump starting73
K
Keyless entry system44
Keylock64
Keys43
Kick -down66
Kickdown67
L
Label information110
Lifting the car112
Locks43
Long load storage53
Lubrication115
Luggage racks - trunk-mounted70
Lumbar support49
M
Maintenance service111
Malfunction indicator lamp17
Manual transmission65, 129
Manually raising convertible top102
Memory function - front seats47
Mirrors - rear/side view50
O
Occupant safety13
Octane rating62
Odometer16
Oil (engine)116, 117, 126
Oil pressure warning light18
Opening the trunk from the inside55
P
Paint touchup104
Parking brake17,30
Parking brake reminder light18
Parking lights20
PCV system113
Polishing107
ProCarManuals.com
Page 94 of 99
Power seats47
Power steering fluid118, 126
R
Radio
-General information186
-SC-813134
-SC-816147
-SC-900/01163
Radio Data System - RDS168
Rear fog light17, 22
Rear suspension128
Rear window demister23
Rear/side-view mirrors50
Refueling62
Remote control (central locking system)44
Remote keyless entry system44
Replacing bulbs89-94
Replacing fuses95
Reporting safety defects13
Road assistance132
Roadholding68
Roll Over Protection System (ROPS)10
Rotating tires82
S
Safety defects - reporting13
Seat belt maintenance13
Seat belts2,3,11
- Automatic Locking Retractor11
- Emergency Locking Retractor11
Seat belts - cleaning108
Seats47
Seats - heated30
Securing cargo57
Service reminder indicator17
Servicing112, 114
Shift lock64
Shiftlock66
Shiftlock release (override)101
Side Impact Protection System (SIPS)8
Side-view mirrors - heated23
SIPS8
Snow chains81
Snow tires81
Spare tire88
ProCarManuals.com