Engine Control, Sensors & Modules - Removal & Installation (Convertible): Other Volvo C70 I

Heated Oxygen Sensors (HO2S)

Front heated oxygen sensor (HO2S)

Scheme 200

The front heated oxygen sensor (HO2S) is used to provide the engine control module (ECM) with information about the remaining oxygen content of the exhaust gases in front of the three-way catalytic converter (TWC). This information is used by the engine control module (ECM) so that it can continually check the combustion so that lambda=1. lambda=1 is the ideal fuel-air ratio, with 14.7 kg air/1 kg fuel.

The heated oxygen sensor uses current control and its signal characteristic is linear. With a linear signal characteristic, the amplitude of the signal curve is low when changing the oxygen content in the exhaust gases. The probe consists of a preheating element (see "Pre-heating heated oxygen sensors") and the actual lambda sensor. The lambda sensor is an oxygen sensitive ceramic body consisting of zirconium oxide. The control module supplies power to the ceramic body, which reacts to the oxygen content of the exhaust gases. This in turn affects the signal to the Engine Control Module (ECM). In order to determine the oxygen content in the exhaust pipe, the heated oxygen sensor needs reference air from the surrounding air. This reference air reaches the heated oxygen sensor via the cable harness.

The engine control module (ECM) can diagnose the heated oxygen sensor. For further information, see Heated oxygen sensor (HO2S) diagnostic . VIDA can be used to read off the calculated lambda value from the heated oxygen sensor.

Rear heated oxygen sensor (HO2S)

Scheme 201

The rear heated oxygen sensor is used to provide the Engine Control Module (ECM) with information about the remaining oxygen content of the exhaust gases behind the three-way catalytic converter (TWC). This information is used by the Engine Control Module (ECM) to check the function of the three-way catalytic converter (TWC). This check is carried out when the conditions for the catalytic converter diagnostics have been met. The rear heated oxygen sensor has no direct effect on regulation of the fuel/air mixture. However the Engine Control Module (ECM) uses the signal to optimize the signal from the front heated oxygen sensor. For further information, see Catalytic converter diagnostic .

The heated oxygen sensor (HO2S) uses voltage control. The signal characteristic is binary. With a binary signal characteristic, the amplitude of the signal curve changes considerably when changing the oxygen content in the exhaust gases. Otherwise its components and function are the same as the front heated oxygen sensor (HO2S).

The engine control module (ECM) can diagnose the rear heated oxygen sensor. The signal can be read using VIDA.

Preheating of the heated oxygen sensors (HO2S)

The heated oxygen sensor (HO2S) only functions above a certain temperature, approximately 300 °C. The normal operating temperature is between 300-900 °C. The heated oxygen sensors (HO2S) are electrically pre-heated so that operating temperature is rapidly reached. This also ensures that the heated oxygen sensors (HO2S) maintain a normal operating temperature and to prevent condensation which could damage the heated oxygen sensor (HO2S).

The heater element in the probe consists of a positive temperature coefficient (PTC) resistor. The system relay supplies the heater element with voltage. The element is grounded in the engine control module (ECM). When the control module grounds the connection a current flows through the PTC resistor. When the heated oxygen sensor (HO2S) is cold, the resistance in the PTC resistor is low and a large current will flow through the circuit. The current from the Engine Control Module (ECM) is pulsed at first to prevent condensation damage to the heated oxygen sensor (HO2S). Depending on the temperature, allowances are made for factors such as the dew point. As the temperature in the PTC resistor rises, the resistance rises, the current falls and switches in stages to a constant current. The pre-heating time for the front heated oxygen sensor (HO2S) is short, approximately 20 seconds. The rear short-term fuel trim takes longer to warm up. This is to prevent damage to the probe. The pre-heating time for the front heated oxygen sensor (HO2S) is short, approximately 20 seconds.

Probe preheating begins as soon as the engine is started. The heater element heats the heated oxygen sensors (HO2S) to approximately 350 °C. The probes maintain this as a minimum temperature.

The engine control module (ECM) can diagnose the heater element.

Scheme 202

The engine coolant temperature (ECT) sensor checks the temperature of the engine coolant. The temperature of the engine coolant is required so that the engine control module (ECM) can regulate

1. the injection period
2. the idle speed
3. the engine cooling fan (FC)
4. the ignition advance
5. engagement and disengagement of the A/C compressor
6. diagnostic functions.

The sensor is a negative temperature coefficient (NTC) type which is supplied with power from the control module (signal) and is grounded in the control module.

The resistance in the sensor changes according to the temperature of the engine coolant. This provides the control module with a signal of between 0.1-4.9 V. The lower the temperature the higher the voltage (high resistance). A high temperature results in low voltage (low resistance).

The engine coolant temperature (ECT) sensor is located beside the thermostat.

The engine control module (ECM) can diagnose the engine coolant temperature sensor. The sensor value can be read off using VIDA.

Scheme 203

The engine cooling fan (FC) has two functions. One is to cool the engine compartment, the other is to cool the condenser when the air conditioning (A/C) compressor is working.

The engine control module (ECM) transmits a pulse width modulated (PWM) signal to the engine cooling fan (FC) control module. The control module then activates the fan at one of three different speeds. The speed of the engine cooling fan (FC) is determined by the engine control module (ECM), depending on the coolant temperature (based on the signal from the engine coolant temperature (ECT) sensor) and the vehicle speed.

When the vehicle is stationary, the engine cooling fan (FC) is activated as follows

1. the first stage is activated at approximately 105 °C and shut of at approximately 100 °C
2. the second stage is activated at approximately 110 °C and shut of at approximately 105 °C
3. the third stage is activated at approximately 115 °C and shut of at approximately 110 °C.

Note. The engine cooling fan may have a post-run of up to approx. 6 minutes after the engine has been turned off. The time for the fan's post-run depends on engine temperature, temperature in the engine compartment and pressure level in the AC-system.

The engine cooling fan (FC) and its control module are behind the radiator.

The engine control module (ECM) can diagnose the engine cooling fan. The fan can be activated using VIDA.

Scheme 204

The mass air flow (MAF) sensor gauges the air mass sucked into the engine. It continuously transmits signals to the engine control module (ECM) about the mass of the intake air. This data is used by the engine control module (ECM) to calculate

1. the injection period
2. the ignition timing
3. the engine load.

The gearbox control module (TCM) also uses this data for its gear shift calculations. This data is transmitted to the gearbox control module (TCM) from the engine control module (ECM) via the high speed side of the Controller area network (CAN).

The mass air flow (MAF) sensor is a hot wire type. Unlike other hot wire types, the mass air flow sensor in the Denso system uses a hot wire which has a ceramic casing. This eliminates the need for a clean burn function.

The mass air flow (MAF) sensor is supplied with battery voltage by the system relay and is grounded in the engine control module (ECM). The signal from the sensor is analogue and varies between 0.5 - 4.5 V depending on the air mass. Low air flow (low mass) results in low voltage, high air flow (high mass) gives high voltage.

The mass air flow (MAF) sensor is positioned between the air cleaner (ACL) housing and the intake manifold.

The mass air flow (MAF) sensor also contains an intake air temperature (IAT) sensor.

The engine control module (ECM) can diagnose the mass air flow (MAF) sensor. The signal can be read using VIDA.

Scheme 205

The outside temperature sensor detects the temperature in the surrounding air. The signal is used by the engine control module (ECM) as a substitute value in the event of a fault in certain components or functions and to control certain diagnostic functions.

The sensor is a negative temperature coefficient (NTC) type which is supplied with power from the control module (signal) and is grounded in the control module.

The resistance in the sensor, which provides a signal between 0.1-4.7 V, changes depending on the outside temperature. Low temperatures produce high voltage (high resistance), high temperatures produce low voltage (low resistance).

The outside temperature sensor is positioned in the left door mirror.

The engine control module (ECM) can diagnose the outside temperature sensor. The sensor value can be read off using VIDA.

Scheme 206

The engine speed (RPM) sensor provides the Engine Control Module (ECM) with information about the speed and position of the crankshaft. The Engine Control Module (ECM) is able to use the signal from the engine speed (RPM) sensor to determine when a piston is approaching top dead center (TDC). However it is unable to use the signal from the engine speed (RPM) sensor to determine whether the piston is in the combustion stroke or whether the exhaust valve is open (exhaust stroke). The signal from the camshaft position (CMP) sensor is also required to determine the operating cycle of the engine.

The signal from the engine speed (RPM) sensor is also used to check the engine for misfires (misfire diagnostics).

Cars with manual transmissions have a series of holes drilled in the periphery of the flywheel. Cars with automatic transmissions have a steel ring with punched holes. This steel ring is welded to the edge of the carrier plate. In both cases, there is 6° between each hole. This arrangement creates a hole for each tooth. There are 360° in one revolution. 6° between each hole means that there are 60 holes. However one hole is not drilled/punched, to create a reference position (tooth) for the crankshaft. This reference position is 72° before the top dead center (TDC) of cylinder 1 on a 5 cylinder engine.

The engine speed (RPM) sensor is at the rear of the engine above the flywheel.

The sensor is inductive with a permanent magnet. An alternating current is induced in the sensor when the flywheel/carrier plate passes the engine speed (RPM) sensor. The generated voltage and frequency increases with the engine speed (RPM).

The signal varies between 0.1 - 100 V (AC) depending on the engine speed (RPM).

The Engine Control Module (ECM) is able to determine the engine speed (RPM) by counting the number of holes per time unit. When the reference tooth passes the engine speed (RPM) sensor, the voltage and frequency drop momentarily to zero, even though the engine is still running. This allows the Engine Control Module (ECM) to determine the position of the crankshaft.

If the signal from the engine speed (RPM) sensor is incorrect or missing, the control module will use the signals from the camshaft position (CMP) sensor, on the condition that the position of the camshaft has been adapted and the car can be driven if there is no signal.

The engine control module (ECM) can diagnose the engine speed (RPM) sensor. The sensor value (engine speed (RPM)) can be read off using VIDA.

Scheme 207

The Engine Control Module (ECM) uses the signals from the camshaft position (CMP) sensor and the engine speed (RPM) sensor to establish the operating cycle of the engine. This enables the engine control module (ECM) to

1. start the engine more quickly
2. control the correct ignition coil and injector
3. function as a substitute for the engine speed (RPM) sensor
4. check the camshaft continuous variable valve timing (CVVT).

The pulse wheel on the camshaft has five teeth with different gaps which correspond to a specific cylinder.

For further information, also see Knock sensor (KS) , Engine speed (RPM) sensor and Camshaft control (CVVT) .

The sensor, which is a magnetic resistor with a permanent magnet, is grounded in the control module and supplied with current from the control module. When one of the teeth on the camshaft pulse wheel passes the camshaft position (CMP) sensor, a signal is transmitted to the control module from the camshaft position (CMP) sensor. The signal varies between 0-1 V and is low when a flank passes the camshaft position (CMP) sensor.

The camshaft position (CMP) sensor is positioned at the rear of the engine on the camshaft with continuous variable valve timing (CVVT).

The engine control module (ECM) can diagnose the camshaft position (CMP) sensor.

Scheme 208

Cars of model year 1999-2000 have a knock sensor. Cars from model year 2001 are equipped with two knock sensors (KS).

The function of the knock sensor (KS) is to monitor combustion knocking from the engine. Knocking may damage the engine and reduces the efficiency of engine combustion.

If the engine control module (ECM) registers knocking from any of the cylinders, the ignition will be retarded for that cylinder at the next combustion stage. If repeated ignition retardation does not prevent knocking, the injection period will be increased. This has a cooling effect.

The sensor is made up of a piezo electrical crystal. If there is engine knock, vibrations (sound waves) spread through the cylinder block to the knock sensor (KS). The resultant mechanical stress in the piezo electrical material in the knock sensors generates a voltage. This signal is transmitted to the Engine Control Module (ECM). The signal corresponds to the frequency and amplitude of the sound waves. This allows the Engine Control Module (ECM) to determine if the engine is knocking. The camshaft position (CMP) sensor and engine speed (RPM) sensor are used to determine the operating cycle of the engine (which cylinder is igniting) and thereby which cylinder is knocking.

The knock sensors (KS) are positioned on the cylinder block below the intake manifold.

The engine control module (ECM) can diagnose the knock sensors (KS).

Scheme 209

The function of the engine coolant level sensor is to alert the driver if the engine coolant level in the expansion tank is too low.

The sensor is a magnetic reed switch, which is enclosed in a pipe on the bottom of the expansion tank. Around the pipe, on the inside of the expansion tank is a float. This float contains a magnet. When the engine coolant level is above minimum, the float is too high in the tank to affect the switch. However if the engine coolant level falls below the minimum level, the magnetic field acts on the switch.

The sensor is supplied with voltage (signal) from the Engine Control Module (ECM) and grounded in chassis. When the engine coolant level in the expansion tank is over a certain level the circuit closes, which produces a low signal. When the engine coolant level is below a certain level the circuit is opened by the engine coolant level sensor, which produces a high signal. When the engine control module (ECM) detects a high signal the information about low engine coolant level is transmitted via the Controller area network (CAN) to the driver information module (DIM), which warns the driver.

Note. There are no functions controlled by the engine which are directly connected to the low coolant level warning lamp. The Engine Control Module (ECM) only transfers the signal which is used by the Driver Information Module (DIM).

The engine control module (ECM) cannot diagnose the engine coolant level sensor.

Scheme 210

The function of the main relay (system relay) is to supply certain components with voltage.

The relay is mechanical and has a closing function. In the rest position the circuit in the relay is open.

The main relay terminals (#30 and #86) are supplied with voltage by the battery. When the ignition key has been turned and the engine control module (ECM) is powered, the terminal (#85) on the main relay is grounded by the engine control module (ECM).

When the terminal (#85) is grounded, the relay is activated and a number of components are powered via the relay terminal (#87).

The engine control module (ECM) can diagnose the main relay.

The main relay is in the relay/fusebox in the engine compartment.

Scheme 211

The air conditioning (A/C) relay controls the A/C compressor. When the climate control module (CCM) requests A/C control, a signal is transmitted to the engine control module (ECM) via the controller area network (CAN) to activate the relay. The engine control module (ECM) temporarily deactivates the relay in the event of

1. full load acceleration
2. too high engine coolant temperature.

The relay is mechanical. It has a closing / breaking function and is supplied with power from the system relay.

In the rest position the circuit in the relay is open.

The system relay supplies the coil and the relay with power. The relay activates when the coil is grounded in the engine control module (ECM), the circuit closes and the A/C compressor is supplied with power via the relay voltage output.

The relay coil is grounded (signal) when the engine control module (ECM) receives a signal via the Controller area network (CAN) from the climate control module (CCM) to activate the relay and start the compressor.

Fuel Pump (FP) Relay

The fuel pump (FP) relay supplies the fuel pump with power. The relay also cuts the power to the pump when the ignition is switched off or if the engine stops. The central electronic module (CEM) also cuts the power to the relay if the supplemental restraint module (SRS) transmits a message indicating that an airbag has deployed.

See "Design and Function, Central electronic module (CEM)".

The central electronic module (CEM) activates and deactivates the relay when requested by the engine control module (ECM) (via the Controller area network (CAN)).

See Design and Function, central electronic module (CEM).

When the ignition is switched on, the engine control module (ECM) sends a signal to the central electronic module (CEM) via the controller area network (CAN) to run the fuel pump (FP) for one seconds. This is so that the pressure increases in the fuel system, shortening the start time.

When the flywheel in the engine rotates (generating a signal from the engine speed (RPM) sensor), the engine control module (ECM) will transmit a request to the central electronic module (ECM) via the Controller area network to start the fuel pump (FP). In the event of the engine stopping, the Engine Control Module (ECM) cancels the "activated fuel pump" signal. The central electronic module (CEM) then switches off the fuel pump (FP).

There is a directly connected cable between the engine control module (ECM) and the central electronic module (CEM). In the event of a fault in the Control area network (CAN), this cable is used by the "activated fuel pump" signal.

Scheme 212

Cars from model year 1999-2000 have an air distribution valve. The air distribution valve supplies the injectors with air. This results in better volumetric efficiency, more effective combustion and therefore cleaner exhaust emissions. The valve is also used for idle air trim but is also slightly open at higher engine speeds.

The valve is directly mounted on the inlet hose for the electronic throttle module (ETM). The valve is connected to a hose which supplies air to the air-shrouded injectors via a distribution pipe.

The valve has its own ignition driver stage and solenoid and is supplied with 12V. The valve is controlled steplessly by the Engine Control Module (ECM) using a variable pulse ratio (duty-cycle) which opens or closes a shutter in the valve.

The valve works primarily during cold starts and when idling, to minimize the release of carbon dioxide and hydro-carbons while maintaining performance and driveability. This is partly because the size of fuel drops is smaller with fuel mixed with air and does not adhere as easily to the walls of the intake manifold when they are cold and damp. This also reduces fuel consumption when cold starting and cuts the warm up time for both the engine and the three-way catalytic converter (TWC).

The total calculated volume of air to be released into the combustion chamber is distributed between both the Electronic Throttle Module (ETM) and the air distribution valve. The input signals to the Engine Control Module (ECM) which affect the operation of the air distribution valve are: the position of the throttle, engine speed (RPM)/position sensor, engine coolant temperature (ECT) sensor, ambient air pressure and ambient air temperature.

The air distribution valve can be diagnosed by the Engine control module (ECM) and can be activated using VIDA.

Scheme 213

The function of the injectors is to spray fuel into the cylinders in the correct spray patterns. This happens sequentially.

The injectors are in the intake manifold.

It is essential that the injectors are correctly installed with no air leakage around them. Fuel leakage from the top of an injector when it is not activated may lead to starting and driving problems.

The engine control module (ECM) controls the injectors using a pulse width modulation (PWM) signal.

The engine control module (ECM) can diagnose the injectors. The injectors can be activated using VIDA.

Air-shrouded injectors

Cars from model year 1999-2000 have air-shrouded injectors.

The injectors are in the air distribution pipe which is in the intake manifold.

The lower section of the injectors has 2 openings in the side where air can enter.

When the needle in the injector starts to rise, the openings are exposed. This allows air to flow in to the center of the valve at high speed, and the fuel and air are finely distributed and mixed.

When the needle rises further, the injector nozzle opens and the air/fuel mixture is released into the combustion chamber.

Scheme 214

The evaporative emission system (EVAP) valve is used to open/close the connection between the EVAP canister and the intake manifold. The valve controls the flow of hydro-carbons (fuel vapor) from the EVAP canister to the engine intake manifold using the vacuum in the intake manifold. This ensures that hydro-carbons stored in the EVAP canister are used in the engine combustion process.

The valve is an electro-magnetic valve which is powered from the system relay. When the valve needs to be opened, it is grounded internally in the engine control module (ECM). The evaporative emission system (EVAP) valve is closed when in the standby position (open-circuit).

When the control module requests that the EVAP canister should be emptied (the hydrocarbons stored in the canister should be released into the engine), the control module deploys the evaporative emission system (EVAP) valve by grounding it. The valve is grounded using a pulse width modulation (PWM) signal, allowing the control module to govern the extent to which the valve opens and adapting the emptying of the canister according to how full it is, engine speed (RPM) and load etc.

The engine control module (ECM) can diagnose the evaporative emission system (EVAP) valve. The valve can be activated using VIDA.

The evaporative emission system (EVAP) valve is close to the intake manifold.

Scheme 215

The camshaft reset valve controls the oil flow to the continuous variable valve timing (CVVT) unit.

The valve consists of an electro-magnetic valve with a spring-loaded piston. There are slits in the piston which channel the engine lubricating oil to different channels in the continuous variable valve timing (CVVT) unit by moving the piston in the reset valve. The continuous variable valve timing (CVVT) unit turns the camshaft (the cam timing changes). The direction in which the camshaft turns depends on the chamber in the CVVT unit which is supplied with oil (pressure).

Also see Camshaft control (CVVT) .

The system relay supplies the reset valve with voltage. The valve is grounded (control stage) in the engine control module (ECM). When the valve is grounded using a pulse width modulation (PWM) signal, the oil flow in the valve can be controlled to the different chambers in the continuous variable valve timing (CVVT) unit at variable rates. This allow the angle of the camshaft to be changed precisely and smoothly.

The engine control module (ECM) can diagnose the camshaft reset valve. The value of the reset valve can be read using VIDA.

Only cars of model year 2000 and later have continuous variable valve timing (CVVT).

The valve is on the cylinder head above the camshaft with camshaft control.

Scheme 216

The ignition coils ignite the fuel / air mixture on command from the engine control module (ECM). The signal is re-transmitted so that the control module knows that it worked.

Each ignition coil has its own integrated power stage.

The ignition coils are in the spark plug wells above each spark plug.

The ignition windings can be diagnosed by the Engine control module (ECM) and can be activated using VIDA.

Scheme 217

The emissions warning lamp in the Driver Information Module (DIM) has a warning symbol. This warning symbol varies depending on the market and model year. The warning symbols are

1. "Engine symbol" (not USA, model year 2001-)
2. "CHECK ENGINE" (MIL - Malfunction Indicator Lamp, USA only).
3. "Lambda symbol" (not USA, model year 1999-2000).

The warning symbol lights when the ignition key is turned to position II and goes out when the engine is started if the engine management system does not detect any faults.

The warning lamp is directly connected to the engine control module (ECM).

The warning lamp will light if there is a fault in one of the monitored parameters in the engine management system. The warning lamp will also light in response to a request transmitted via the Control area network (CAN) if there is a fault in one of the following systems which affects emissions

1. gearbox control module (TCM)
2. brake control module (BCM)
3. electronic throttle module (ETM).

Scheme 218

The manifold absolute pressure (MAP) sensor detects quick pressure changes in the intake manifold after the throttle. The signal from the sensor is used by the engine control module (ECM) as an addition to the mass air flow (MAF) sensor to calculate the injection period.

The semi-conductor sensor is grounded in the control module and is supplied with power from the control module.

The resistance in the sensor changes depending on the pressure in the intake manifold, giving a signal of 0.5 - 4.5 V. Low pressure results in low voltage, high pressure in high voltage.

The engine control module (ECM) can diagnose the manifold absolute pressure sensor. The sensor signal can be read using VIDA.

The manifold absolute pressure (MAP) sensor is on top of the radiator and is connected to the intake manifold by a hose.

Scheme 219

The fuel tank pressure sensor detects the pressure in the fuel tank. The signal from the sensor is used by the engine control module (ECM) during diagnostics to check for leakage in the fuel tank system.

The sensor, which is a piezo resistor, is grounded in the control module and supplied with power from the control module.

The resistance in the sensor changes depending on the pressure in the fuel tank, giving a signal of 0.5 - 4.5 V. Low pressure results in low voltage, high pressure in high voltage.

The tank pressure sensor can be diagnosed by the Engine control module (ECM), and the sensor's signal can be read using VIDA.

The fuel tank pressure sensor is positioned on top of the fuel tank on cars with leakage diagnostics for the evaporative emission (EVAP) system.

Scheme 220

The EVAP canister shut-off valve is used to close the connection between the EVAP canister/fuel tank system and fresh air (atmospheric pressure) when leak diagnostics are carried out on the cars with the evaporative emission (EVAP) system.

The valve is an electro-magnetic valve which is powered from the system relay. When the valve needs to be closed, it is grounded internally in the engine control module (ECM). The valve is open when in the rest position (open-circuit).

The valve can be diagnosed by the engine control module (ECM) and can be activated using VIDA.

The valve is next to the EVAP canister on cars with leak diagnostics for the evaporative emission (EVAP) system.

Preparations

Note. Read off data from the control module before replacing the control module. This is carried out via VIDA communication. The current data must be entered into the new control module after replacement.

Scheme 221

Ignition off.

Remove the key.

Note. The key must be removed to ensure that the ignition is not switched on by mistake.

Note. After the key has been removed: Wait 1 minute before starting work.

Remove

1. the surround for the combined instrument panel by pulling it straight out.

Scheme 222

1. the 4 screws
2. the connector
3. the combined instrument panel.

Installing The Driver Information Module (DIM)

Install

In reverse order.

Ordering Software And Programming Control Modules

Order software according to the table below.

Program the new control module according to the table below.

Finishing Work

The customer parameters must be programmed after replacing the control module. The clock must also be reset. Finally, check that no diagnostic trouble codes (DTCs) were stored during replacement. Information about programming control modules and reading off diagnostic trouble codes (DTCs) can be found under VIDA communication.

Replacing Engine Control Module (ECM)

C70, S70, V70 -2000

1. For B5xx4T -2002, see «Replacing the engine control module (ECM)»(ref-404033-S08158354962011061000000)
2. For B5xx4T 2003-, see «Engine control module (ECM), replacing»(ref-404033-S28939388822011061000000)
3. For B5xx4S see «Replacing the engine control module (ECM)»(ref-404033-S34042663912011061000000) .

Removing the temperature sensor

Remove the cap from the expansion tank.

Raise the car. Remove the lower splashguard.

Position a container under the engine drain cock. Drain the engine coolant.

Close the cock.

Install the lower splash guard.

Lower the car.

Scheme 223

Remove the screw holding the engine stabilizer brace to the bracket on the engine.

Undo the clamp holding the return hose for the power steering.

Remove the cross stay.

Scheme 224

Remove the crankcase ventilation pipe from the intake manifold. Start with the cover.

Remove the plastic hoses between the turbocharger (TC) and the charge air cooler and between the air cleaner (ACL) and the turbocharger (TC).

Remove the clamp for the intake manifold at the turbocharger (TC) for cylinders 1, 2 and 3. Detach the upper section of the pipe by turning it towards the firewall.

Scheme 225

Remove

1. the upper timing belt cover. Lift up the servo reservoir and place it on top of the engine. WARNING: Seal the cover for the servo reservoir. Check that no oil leaks out. Servo oil is highly inflammable.
2. the screw for the front timing belt cover. See «REMOVING THE FRONT TIMING COVER»(ref-438319-S23581740062011120100000) .
3. the timing belt cover. Disconnect the connector for the sensor cable.

Remove the variable valve timing solenoids and place them to one side.

Remove the screw for the cable duct.

Scheme 226

Remove the thermostat housing with the cable duct.

Clean the mating surfaces of the cylinder block. Ensure that no dirt enters the fluid ducts.

Scheme 227

Secure the thermostat housing in a vise. Remove the sensor.

Note. Handle the thermostat housing carefully when securing it in the vise.

Installing the temperature sensor

Note. For tightening torques, see Tightening torque .

Clean the thermostat housing mating surfaces. Ensure that there is no dirt left in the thermostat housing.

Install

1. the new sensor. Use a new gasket . Tighten to 20 Nm . Ensure that the sensor cable is correctly routed in the thermostat housing and in the cable duct
2. the thermostat housing using a new gasket. Tighten to 17 Nm
3. the screw for the cable duct. Tighten to 10 Nm
4. the variable valve timing solenoids. Tighten to 10 Nm
5. the front timing belt cover. See «Installing the front timing cover»(ref-438319-S29593724362011120100000) . The mudguard over the right drive shaft boot may come loose. If this happens, secure it from underneath
6. the screw for the front timing belt cover. Tighten to 12 Nm
7. the servo reservoir. Check that the hoses are correctly positioned
8. the upper timing belt cover.

Install the plastic hoses between the turbocharger (TC) and the charge air cooler and between the air cleaner (ACL) and the turbocharger (TC).

Install the crankcase ventilation pipe on the intake manifold.

Tighten all hose clamps.

Install

1. the engine stabilizer brace. Tighten to 50 Nm
2. the torque rod on the bracket on the engine. Tighten to 80 Nm
3. the clamp holding the return hose for the power steering.

Engine Coolant Temperature (ECT) Sensor, Replacing (B5244S; 2000)

S60, V70 2000-, S80

1. For B5244S/S2 1999-, see «Thermostat / temperature sensor, engine coolant, replacing»(ref-403969-S34824642562011061000000)
2. For B5244S/S2/S6 2002-, see «Replacing the thermostat and/or engine coolant temperature sensor»(ref-403969-S21007574872011061000000) .

Scheme 228

Remove the intake pipe for the air cleaner housing (ACL). Disconnect both the connectors for the engine cooling fan (FC).

Remove

1. The evaporative emission system (EVAP) valve from the engine cooling fan (FC) shroud
2. the hose clamps and charge air pipe/hose on the right-hand side (turbo charged engines only).

Scheme 229

Remove the four tie straps that hold the cable harness secure at the fan shroud.

Note. Certain vehicles have three tie straps and a clip holding the cable harness at the fan shroud.

Lift out the hose for the expansion tank from the holders on top of the fan shroud

Remove

1. the cool box plastic hose from the fan shroud.
2. both the screws holding the fan shroud.

Release the hose for the coolant reservoir from the fan shroud.

Scheme 230

Carefully lower the fan shroud and align with the holders. Route the cable harness behind the holder (3).

Tighten both the mounting screws

Press the hose down from the expansion tank into the holder on the fan shroud

Transfer the clips from two tie-straps to the tie straps that have two catches (1).

Secure the cable harness by the fan shroud using tie straps (1) and (2).

Install

1. the canister purge (CP) valve
2. the hose clamp and charge air pipe/hose on the right-hand side (turbo charged engines only)
3. the intake manifold to the air cleaner (ACL) housing.

Connect the engine cooling fan (FC) connectors.

Scheme 231

Transfer the bracket (1) to the new fan shroud.

Install the connectors for the fan on the bracket using the holder from the service kit (2).

Scheme 232

For vehicles with chassis number according to the table: Replace the cover on the cool box (Engine control module (ECM), Transmission control module (TCM)).

Scheme 233

Apply the decal to the cover of the cool box.

Engine Speed (RPM) Sensor, Replacing

C70

1. For B5xx4T, see «Replacing flywheel sensor»(ref-404033-S37370485502011061000000) .

Scheme 234

1. Jack up the car.
2. Remove protection cover from under engine.
3. Drain the coolant as described in «Replacing radiator/charge air cooler (CAC)»(ref-438318-S07767039222011120100000) .
4. Lower the car.
5. Release coolant hose from thermostat housing using pliers.
6. Remove thermostat housing.
7. Remove sensor.

Scheme 235

1. Jack up the car.
2. Remove protection cover from under engine.
3. Drain the coolant as described in «Radiator / charge air cooler (CAC), replacement»(ref-438318-S36936788022011120100000) .
4. Lower the car.
5. Loosen oil reservoir for servo pump as described in «Fluid reservoir, reservoir»(ref-404026-S11070193112011061000000) .
6. Remove coolant reservoir and put it to one side.
7. Remove screws and outer/upper timing-gear casing.
8. Remove screws and wire channel.
9. Disconnect connector.
10. Remove 4 screws and thermostat housing.
11. Remove sensor and wires.

Scheme 236

1. Install lock grip pliers on the return hose from the fluid reservoir as close to the power steering pump as possible. NOTE: Place paper over the generator (GEN) as protection against oil.
2. Remove the return hose from the power steering pump.

Scheme 237

1. Lift the fluid reservoir from the mounting. Remove the lock grip pliers. Drain the oil into a container. WARNING: Avoid skin contact with the oil.
2. Disconnect both the hoses from the reservoir
3. Remove the reservoir.

Engine temperature sensor, 6-cylinder

1. Install thermostat housing sensor.
2. Position wires in slot on thermostat housing.

Note. The white marks should be positioned in lower opening of slot, from underneath.

1. Position gasket on thermostat housing correctly and install thermostat housing using two of the screws.
2. Position thermostat housing correctly and tighten the four screws.
3. Position wire channel correctly and position wire in channel.
4. Tighten screw on wire channel.
5. Connect the connector.
6. Install outer/upper timing-gear casing.
7. Install coolant reservoir.
8. Install oil reservoir for servo pump as described in «Fluid reservoir, reservoir»(ref-404026-S11070193112011061000000) .

Follow-on work, 6-cylinder

1. Fill up coolant.
2. Warm the engine until the thermostat opens. Switch engine off and check the level. Re-fill if necessary.
3. Check for leaks.
4. Check in VIDA vehicle communication (read-out of parameter values), for current engine system, that the engine temperature shown appears correct.

Engine temperature sensor, 5-cylinder

Install in reverse order.

Follow-on work, 5-cylinder

1. Fill up coolant.
2. Warm the engine until the thermostat opens. Switch engine off and check the level. Re-fill if necessary.
3. Check for leaks.
4. Check in VIDA vehicle communication (read-out of parameter values), for current engine system, that the engine temperature shown appears correct.

General

The Controller area network (CAN) is monitored and controlled by the central electronic module. When the central electronic module detects a fault in the controller area network a diagnostic trouble code (DTC) is set in the central electronic module. There are different diagnostic trouble codes depending on the type of malfunction detected.

Types of error which are handled are

1. Electrical faults
2. No communication from the control module
3. Faulty communication.

Electrical Faults

In the event of errors in the signal levels on the communication cables for the central electronic module a diagnostic trouble code (DTC) is stored in the central electronic module. A check is carried out on each communication cable to the central electronic module, CAN L, CAN H on the low speed side and CAN L and CAN H on the high speed side There are two different levels which are detected (low or high).

This gives eight diagnostic trouble codes for detecting electrical faults.

The diagnostic trouble codes for electrical faults are CEM-DF0X for the low speed network and CEM-DF1X for high speed network.

No Communication From The Control Module

The central electronic module knows which control modules are in the Controller area network and checks that all the control modules communicate. If any control module on the Controller area network (CAN) does not communicate a diagnostic trouble code is stored in the central electronic module. There is a diagnostic trouble code for each control module. The diagnostic trouble codes are CEM-1A5X respectively CEM-1A6X.

Faulty Communication

Each control module except for the central electronic module has two diagnostic trouble code types which are related to faulty communication (the central electronic module only has one type of diagnostic trouble code).

These are

1. Faulty messages
2. Configuration fault (missing in the central electronic module (CEM)).

Faulty messages

When a control module sends errors in the messages a number of times, the control module stops communication. The diagnostic trouble code is stored in the control module which caused the faulty message. If the fault is permanent it is impossible to communicate with the control module. It is not possible to read off diagnostic trouble codes from the control module with the switched off communication.

The diagnostic trouble codes (DTCs) are XXX-E000 for the high speed network and XXX-E001 for low speed network.

Configuration fault

If the signal configuration of a control module does not correspond to the signal configuration of the central electronic module, a diagnostic trouble code is stored in the control module with the faulty signal configuration.

The diagnostic trouble code for configuration fault is XXX-E003.

Final Drive Housing, Replacing Upper Bushing

Special tools

9995503

Note. The tool and method to install the upper bushing on model year 92- has changed. The new tool has P/N 999 5503-1.

Scheme 238

The bushing has a version and mounting position common to all engine alternatives.

The bushing consists of two halves held together by a sleeve

Scheme 239

The breather hole has been moved from the housing to the cover.

Scheme 240

A new tool has been developed for replacing the bushing. Work is carried out on the unit when removed.

Location

Board, 16/17-1 (whole board)

Location, G8

Scheme 241

Grind out the sleeve cone on one side and knock the halves apart.

Scheme 242

Install the new bushing halves.

Use tool 9995503 so that the conical seat under the screw head on the tool comes against the side of the sleeve to be coned (riveted). Lubricate the underside of the screw head using petroleum jelly.

Scheme 243

Press the halves with the tool and guide the tool up so that the bushing halves are opposite each other as illustrated. Then tighten to 200 Nm .

Note. Important that the tool is tightened to 200 Nm so that the bushing sleeve cones correctly.

Scheme 244

Check that the bushing is in position.

Information

Example of use of the frozen values

Faults can be intermittent, which is important to remember when fault-tracing for possible causes. If the fault is not present when the vehicle is in the workshop, a fault cause can be missed as the values can be correct when fault-tracing is carried out. A good indication of when the fault occurred the first time are the frozen values that can be read out using VIDA/Details.

The frozen values are stored immediately after a fault has been detected. Most parameters in the frozen values are the same for all faults and indicates a general status when a fault has been detected, e.g. engine speed, load, coolant temperature, vehicle speed and battery voltage. Some of them have been selected to give a better understanding of the specific fault. Diagnostic Trouble Code (DTC) ECM-903F Throttle position (TP) can be used as an example of how the frozen values can be used (this is only one example and there may be deviations in reality).

One of the checks given in fault-tracing is "voltage supply to throttle unit" and continues with a suggestion to check the battery and charging system. However, the battery's condition, with the vehicle in the workshop, does not show the battery voltage when the fault was detected. The best information is in the frozen values, i.e. the voltage that the Engine control module (ECM) detected, when the Electronic throttle module (ETM) indicated the fault.

However, remember that this is not an indication of the voltage supply to the Electronic throttle module (ETM), but to the Engine control module (ECM). If the Engine control module (ECM), according to the frozen values, had a good voltage, the battery worked. The voltage supply to the Electronic throttle module (ETM) should therefore be checked separately.

In this case, we assume that the vehicle had a low battery voltage in the workshop. As seen in the frozen values however, the battery voltage was correct when the fault occurred, and this was therefore probably not the cause. This is an example of how the frozen values can be used, to make fault-tracing more efficient and prevent taking too much time fault-tracing incorrectly. This prevents fault-tracing and correcting a fault that was not actually the cause of the problem, which was originally to be solved.

The odometer setting (km) is included among the frozen values in the Engine control module (ECM). This makes a fast comparison with the odometer counter possible, so that one can determine if the fault occurred as part of the fault-tracing and can be ignored.

For example, the CAN related diagnostic Trouble Codes (DTCs) can be detected when the battery voltage drops when working on the vehicle, by the passenger compartment lighting and other loads draining the battery. The frozen values indicate the odometer setting in km. Multiplying this value by 0.62 gives the distance in miles. The current distance in miles and km can be read out using VIDA.

The following should be taken into account when using frozen values for fault-tracing. The frozen values, that should be used with care, are those that have been stored for CAN and are related to Diagnostic Trouble Codes (DTCs) for the Electronic throttle module (ETM).

If the Electronic throttle module (ETM) detects that the communication to the Engine control module (ECM) is interrupted, error flags are stored in the Electronic throttle module (ETM). These error flags are sent to the Engine control module (ECM) as soon as communication on the CAN is working again. This means that the Engine control module (ECM) stores the Diagnostic Trouble Codes (DTCs) as soon as the Electronic throttle module (ETM) supplies them.

This, in turn means that it is at this time that the frozen values are stored. For the Electronic throttle module (ETM) this means that the frozen values occur from a point in time after the fault first occurred.

Read Off Fault Type

Actual fault type with data.

Previous Fault Type

This fault type may be the same as above, although not necessarily.

All read off data is based on this fault type.

Time Before The Data Was Frozen

How long the fault existed before the frozen values were created.

Time After Engine Start

How long since the engine was started.

Outside Temperature

Displays the actual outside temperature when the frozen values were created. The value is given in °C.

Atmospheric Pressure

Displays the actual atmospheric pressure when the frozen values were created. The value is given in hPa.

Vehicle Speed

Displays the actual vehicle speed when the frozen values were created. The value is given in km/h.

Engine Speed

Displays the actual engine speed (RPM) when the frozen values were created. The value is given in RPM.

Mass Air Flow g/Stroke

Displays the actual mass air flow in g/stroke when the frozen values were created.

Intake Pressure

Displays the actual pressure in the intake manifold when the frozen values were created. The value is given in hPa.

Engine Coolant Temperature (ECT)

Displays the actual engine temperature when the frozen values were created. The value is given in °C.

Lambda Compensation

Lambda compensation is rapid adjustment of the fuel adaptation value which continually adjusts the fuel air mixture. The area of adjustment is between 0-2. The normal value is 1 (no adaptation).

Long Term Fuel Trim

Long term fuel trim is slow adjustment of the fuel trim value that is used to adapt the fuel / air mixture during longer periods. This value takes into consideration factors such as the aging of components and component tolerances etc. The area of adjustment is between 0-2. The normal value is 1 (no adaptation).

Accelerator Pedal (AP) Affected

Indicates whether the accelerator pedal (AP) was depressed or not when the frozen values were created.

Probe Control

Indicates whether the engine was regulated using fuel trim or not when the frozen values were created.

Fuel Shut-Off System

Indicates whether the fuel shut-off system was active or not when the frozen values were created.

Operating Cycle

Indicates whether the engine was active or not when the frozen values were created.

This happens when the engine speed (RPM) exceeds 600 RPM

Warm-Up Cycle

Indicates whether a warm-up cycle had been run or not when the frozen values were created.

A warm-up cycle is run if the engine coolant temperature (ECT) is between -7° C and +35° C when the engine is started.

Gear Selected

Indicates whether a gear was selected or not when the frozen values were created.

Engine Cooling Fan (FC)

Indicates whether the engine cooling fan (FC) was active or not when the frozen values were created.

A/C Requested

Indicates whether the air conditioning (A/C) was selected or not when the frozen values were created.

Air Conditioning (A/C) Compressor Active

Indicates whether the air conditioning (A/C) compressor was active or not when the frozen values were created.

Brake Pedal Switch

Indicates whether the brake pedal was affected or not when the frozen values were created.

EVAP Canister Purge Valve Active

Indicates whether the EVAP canister purge valve was active or not when the frozen values were created.

Cruise Control Active

Indicates whether the cruise control was active or not when the frozen values were created.

EVAP Canister Shut-Off Valve

Indicates whether the EVAP canister shut-off valve was active or not when the frozen values were created.

State, Fuel Trim

Depending on the prevailing circumstances when the frozen values were created, one of the following alternatives may be stored.

1. no fuel trim, the start conditions have not been met . This condition occurs at the crank or immediately after start before fuel trim has started
2. fuel trim with two probes . This situation occurs during driving when both probes are used during fuel trim (part load)
3. no fuel trim, operation with predefined values . This situation occurs during hard acceleration or during fuel shut-off when there is no fuel trim and operation is under predefined values
4. no fuel trim, operation with a system fault . This situation occurs when an earlier diagnostic trouble code (DTC) was stored that caused the fuel trim to be disabled
5. fuel trim with one probe (front) . This situation occurs at idling speed or during light acceleration when one probe (front) is used during fuel trim.

Battery Voltage

Displays the actual battery voltage when the frozen values were created.

Passenger Compartment Temperature

Displays the temperature in the passenger compartment in the instant the frozen values were created.

Odometer Setting

Displays the odometer setting in the instant the frozen values were created.

Installing The Lock

Note. Screw in the screw until it takes.

Install the fuel rail.

Press in the secondary lock (2).

Screw the screw (1) right in.