Engine Control Module (ECM) Diagnostic Trouble Codes - 1 of 13: Other Volvo XC90 I

FAULT-TRACING INFORMATION

If the fault is intermittent, do not verify fault-tracing if the fault does not recur.

It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

CHECKING COMPONENTS AND CONNECTORS

Check the connector for the outside temperature sensor. Check for contact resistance and oxidation.

The sensor may be defective if the above fault tracing and corrective action does not remedy the fault.

Remedy as necessary.

Other information

1. For outside temperature sensor - 2006 see «OUTSIDE TEMPERATURE SENSOR DOOR MIRROR, REPLACING»(ref-494820-S21392095062012081600000)
2. For outside temperature sensor 2007 - see «OUTSIDE TEMPERATURE SENSOR»(ref-494820-S33534835522012081600000)
3. see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000) .

Scheme 40

1. Continue Refer to «VERIFICATION»(ref-476747-S10899418362012060500000)

VERIFICATION

HINT: After carrying out the repair, check that the fault has been remedied.

Scheme 41

Scheme 42

Scheme 43

1. Ignition off.
2. Reconnect connectors, reinstall components.
3. Ignition on.
4. Read off outside temperature.

Is the temperature within its permitted range?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S42089927802012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off.
2. Reconnect connectors, reinstall components.
3. Ignition on.
4. Read off outside temperature.

Is the temperature within its permitted range?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S39862829152012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off.
2. Reconnect connectors, reinstall components.
3. Ignition on.
4. Read off outside temperature.

Is the temperature within its permitted range?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S18427210672012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

REPLACING THE COMPONENT

The engine control module (ECM) has registered an internal fault.

If the fault is intermittent, it has been registered previously but is no longer present. Intermittent faults can be caused by interference at start up of the engine control module (ECM) or may be a different type of fault which occurs on different occasions. The fault is evaluated depending on how it occurs. Replace the engine control module (ECM) if the fault recurs.

Replace the engine control module (ECM) in the event of a permanent fault.

see ENGINE CONTROL MODULE (ECM), REPLACING

Remedy as necessary.

1. Continue Refer to «INFORMATION»(ref-476747-S12084060882012060500000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

INTERNAL FAULT

see INTERNAL FAULT

see INTERNAL FAULT

see INTERNAL FAULT

see INTERNAL FAULT

see INTERNAL FAULT

see INTERNAL FAULT

see INTERNAL FAULT

see INTERNAL FAULT

see INTERNAL FAULT

see INTERNAL FAULT

see INTERNAL FAULT

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Ignition on
4. Read off the intake air temperature (IAT).

Is the temperature within its permitted range?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S31327508702012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

CHECKING THE CONNECTOR

1. Ignition off
2. Check the boost pressure sensor connector. Check for contact resistance and oxidation. NOTE: The intake air temperature (IAT) sensor is integrated in the boost pressure sensor
3. Reinstall the components, reconnect the connectors etc.
4. Ignition on
5. Read off the intake air temperature (IAT). Check that the intake air temperature (IAT) is within its permitted range. If the intake air temperature (IAT) is now within its permitted range, the fault was caused by loose connections in the connector. Other information: For B5xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000) For B6xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000)

Is the temperature within its permitted range?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «CHECKING THE WIRING AND COMPONENT»(ref-476747-S39563215632012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Ignition on
4. Read off the intake air temperature (IAT).

Is the temperature within its permitted range?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S05220597632012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

1. Ignition off
2. Check the boost pressure sensor connector and terminal. Check for contact resistance and oxidation. NOTE: The intake air temperature (IAT) sensor is integrated in the boost pressure sensor. If no errors are found and the fault is permanent, replace the intake air temperature (IAT) sensor. Remedy as necessary. Other information: see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000) For resistance values, see «COMPONENT SPECIFICATIONS»(ref-476694-S25701556572012060500000) For B5xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000) For B6xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000)

1. Continue Refer to «VERIFICATION»(ref-476747-S22351624242012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

Scheme 44

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Start the engine. Allow the engine to idle for 5 minutes
4. Read off diagnostic trouble codes (DTCs). The fault has been remedied if status of the diagnostic trouble code (DTC) is intermittent.

Is the status of the diagnostic trouble code (DTC) intermittent?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S25850758342012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

CHECKING THE INTAKE SYSTEM

Check the mass air flow (MAF) sensor connector. Check for contact resistance and oxidation.

Check the intake system for leakage. In particular, check the hoses and hose connectors between the mass air flow (MAF) sensor and the throttle unit. Check for leakage and damage.

Check the inside of the throttle body (TB). Check for contamination. When the throttle body (TB) is contaminated, the air flow to the engine is impaired and diagnostic trouble code (DTCs) or fault symptoms can occur.

Clean the throttle body (TB) if needed.

If no fault is found, try a new mass air flow (MAF) sensor.

Remedy as necessary.

Other information

1. see «AIR LEAKAGE IN THE INTAKE SYSTEM, CHECKING»(ref-476750-S00778580782012060500000)
2. see «THROTTLE BODY (TB), CLEANING»(ref-476750-S20438140822012060500000)
3. see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000)
4. see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

1. Continue Refer to «VERIFICATION»(ref-476747-S20065942752012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off.
2. Reinstall the connectors, components etc.
3. Ignition on.
4. Read off and make a note of the adaptation value.
5. Start the engine. Increase the engine speed (RPM) a couple of times.
6. Read off the adaptation value and check that the adaptation value approaches 1.

Does the adaptation value approach 1?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S25312729322012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Check the mass air flow (MAF) sensor connector. Check for contact resistance and oxidation.

Check the intake system for leakage. In particular, check the hoses and hose connectors between the mass air flow (MAF) sensor and the throttle unit. Check for leakage and damage.

Check the inside of the throttle body (TB). Check for contamination. When the throttle body (TB) is contaminated, the air flow to the engine is impaired and diagnostic trouble code (DTCs) or fault symptoms can occur.

Clean the throttle body (TB) if needed.

If no fault is found, try a new mass air flow (MAF) sensor.

Remedy as necessary.

Other information

1. see «AIR LEAKAGE IN THE INTAKE SYSTEM, CHECKING»(ref-476750-S00778580782012060500000)
2. see «THROTTLE BODY (TB), CLEANING»(ref-476750-S05163330712012060500000)
3. see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000)
4. see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

1. Continue Refer to «VERIFICATION»(ref-476747-S31235565432012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off.
2. Reinstall the connectors, components etc.
3. Ignition on.
4. Read off and make a note of the adaptation value.
5. Start the engine. Increase the engine speed (RPM) a couple of times.
6. Read off the adaptation value and check that the adaptation value approaches 1.

Does the adaptation value approach 1?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S36002054652012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Check the mass air flow (MAF) sensor connector. Check for contact resistance and oxidation.

Check the induction system for air leaks. In particular, check the hoses and hose connectors between the mass air flow (MAF) sensor and the throttle unit. Check for leakage and damage.

Check the inside of the throttle body (TB). Check for contamination. When the throttle body (TB) is contaminated, the air flow to the engine is impaired and diagnostic trouble code (DTCs) or fault symptoms can occur. Clean the throttle body (TB) if needed.

Remedy as necessary.

Other information

1. see «AIR LEAKAGE IN THE INTAKE SYSTEM, CHECKING»(ref-476750-S00778580782012060500000)
2. see «THROTTLE BODY (TB), CLEANING»(ref-476750-S20438140822012060500000)
3. see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000)
4. see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

1. Continue Refer to «VERIFICATION»(ref-476747-S19292060372012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off.
2. Reinstall the connectors, components etc.
3. Ignition on.
4. Read off and make a note of the adaptation value.
5. Start the engine. Increase the engine speed (RPM) a couple of times.
6. Read off the adaptation value and check that the adaptation value approaches 1.

Does the adaptation value approach 1?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S19988528172012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Check the mass air flow (MAF) sensor connector. Check for contact resistance and oxidation.

Check the induction system for air leaks. In particular, check the hoses and hose connectors between the mass air flow (MAF) sensor and the throttle unit. Check for leakage and damage.

Check the inside of the throttle body (TB). Check for contamination. When the throttle body (TB) is contaminated, the air flow to the engine is impaired and diagnostic trouble code (DTCs) or fault symptoms can occur. Clean the throttle body (TB) if needed.

Remedy as necessary.

Other information

1. see «AIR LEAKAGE IN THE INTAKE SYSTEM, CHECKING»(ref-476750-S00778580782012060500000)
2. see «THROTTLE BODY (TB), CLEANING»(ref-476750-S05163330712012060500000)
3. see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000)
4. see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

1. Continue Refer to «VERIFICATION»(ref-476747-S17428568442012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off.
2. Reinstall the connectors, components etc.
3. Ignition on.
4. Read off and make a note of the adaptation value.
5. Start the engine. Increase the engine speed (RPM) a couple of times.
6. Read off the adaptation value and check that the adaptation value approaches 1.

Does the adaptation value approach 1?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S27794383082012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

FLOW TOO LOW OR TOO HIGH

see FLOW TOO LOW OR TOO HIGH

see FLOW TOO LOW OR TOO HIGH

see FLOW TOO LOW OR TOO HIGH

see FLOW TOO LOW OR TOO HIGH

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reinstall the connectors, components etc.
3. Ignition on
4. Check that the air flow is correct. The value must be approximately 0 kg/h with the engine switched off
5. Start the engine. Read off the air flow. The value may vary by between 12-20 kg/h at idle speed, depending on the engine load and temperature. The value may be in excess of 20 kg/h if the engine is cold
6. Increase the engine speed (RPM) and check that the air flow increases with increased engine speed.

Are the values correct?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S01931040942012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

SIGNAL TOO HIGH

see SIGNAL TOO HIGH

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reinstall the connectors, components etc.
3. Ignition on
4. Check that the air flow is correct. The value must be approximately 0 kg/h with the engine switched off
5. Start the engine. Read off the air flow. The value may vary by between 12-20 kg/h at idle speed, depending on the engine load and temperature. The value may be in excess of 20 kg/h if the engine is cold
6. Increase the engine speed (RPM) and check that the air flow increases with increased engine speed.

Are the values correct?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S19766653252012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

SIGNAL TOO LOW

see SIGNAL TOO LOW

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reinstall the connectors, components etc.
3. Ignition on
4. Read off the boost pressure sensor pressure and atmospheric pressure sensor pressure
5. The difference between the pressure sensors should not be greater than 140 hPa.

Is the difference between the pressure sensors less than 140 hPa?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S25557391662012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

see SIGNAL TOO HIGH

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reinstall the connectors, components etc.
3. Ignition on
4. Read off the boost pressure sensor pressure and atmospheric pressure sensor pressure
5. The difference between the pressure sensors should not be greater than 140 hPa.

Is the difference between the pressure sensors less than 140 hPa?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S15268809302012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

SIGNAL TOO LOW / SIGNAL TOO HIGH

see SIGNAL TOO LOW / SIGNAL TOO HIGH

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reinstall the connectors, components etc.
3. Ignition on
4. Read off the boost pressure sensor pressure and atmospheric pressure sensor pressure
5. The difference between the pressure sensors should not be greater than 140 hPa.

Is the difference between the pressure sensors less than 140 hPa?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S31747264152012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

FAULTY SIGNAL

see FAULTY SIGNAL

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reinstall the connectors, components etc.
3. Ignition on
4. Read off the boost pressure sensor pressure and atmospheric pressure sensor pressure
5. The difference between the pressure sensors should not be greater than 140 hPa.

Is the difference between the pressure sensors less than 140 hPa?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S34025176692012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

SIGNAL MISSING

see SIGNAL MISSING

see SIGNAL TOO HIGH

see SIGNAL TOO HIGH

see SIGNAL TOO LOW / SIGNAL TOO HIGH

see SIGNAL TOO LOW / SIGNAL TOO HIGH

CHECKING CABLES AND CONNECTORS

Check signal cable between engine control module (ECM) #A22 (#A22) and mass air flow (MAF) sensor #5 for an intermittent short-circuit to supply voltage according to SHORT-CIRCUIT TO SUPPLY VOLTAGE, INTERMITTENT FAULTS .

Check power supply cable between engine control module (ECM) #A58 (#A58) and mass air flow (MAF) sensor #3 for an intermittent open-circuit according to OPEN-CIRCUIT, INTERMITTENT FAULTS

Other information

1. Connecting the breakout box/accessing the control module, see «CONNECTING THE BREAKOUT BOX»(ref-476691-S38062545372012060500000) .
2. To access/replace the Mass Air Flow (MAF) sensor, see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000) .
3. With the ignition on and mass air flow (MAF) sensor connector connected the voltage at mass air flow (MAF) sensor #2 should be approximately U bat , mass air flow (MAF) sensor #3 should be ground and mass air flow (MAF) sensor #5 should be approximately 1 volt.
4. For 5 cylinder turbocharged engines -2004, see «SIGNAL DESCRIPTION»(ref-476694-S26303328522012060500000)
5. For 5 cylinder turbocharged engines 2005-, see «SIGNAL SPECIFICATION»(ref-476694-S29505181092012060500000) .
6. For 6 cylinder engines -2004, see «SIGNAL SPECIFICATION»(ref-476694-S39196199822012060500000)
7. For 6 cylinder engines 2005-, see «SIGNAL SPECIFICATION»(ref-476694-S31890965202012060500000) .

1. Continue Refer to «INFORMATION»(ref-476747-S24196596222012060500000)

If the fault is intermittent, do not verify fault-tracing if the fault does not recur.

It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).

CHECKING CABLES

Check the cable between engine control module (ECM) #A22 (#A22) and mass air flow (MAF) sensor #5 for a short-circuit to supply voltage according to SHORT-CIRCUIT TO SUPPLY VOLTAGE. PERMANENT FAULTS .

Check the ground lead between #A58 (#A58) and mass air flow (MAF) sensor #3 for an open-circuit according to OPEN-CIRCUIT, PERMANENT FAULTS

Remedy as necessary

Other information

1. Connecting the breakout box/accessing the control module, see «CONNECTING THE BREAKOUT BOX»(ref-476691-S38062545372012060500000) .
2. To access/replace the Mass Air Flow (MAF) sensor, see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000) .
3. With the ignition on and the mass air flow (MAF) sensor connector connected the voltage at mass air flow (MAF) sensor #2 should be approximately U batt , mass air flow (MAF) sensor #3 should be ground and mass air flow (MAF) sensor #5 should be approximately 1 V.
4. For 5 cylinder turbocharged engines -2004, see «SIGNAL DESCRIPTION»(ref-476694-S26303328522012060500000)
5. For 5 cylinder turbocharged engines 2005-, see «SIGNAL SPECIFICATION»(ref-476694-S29505181092012060500000) .
6. For 6 cylinder engines -2004, see «SIGNAL SPECIFICATION»(ref-476694-S39196199822012060500000)
7. For 6 cylinder engines 2005-, see «SIGNAL SPECIFICATION»(ref-476694-S31890965202012060500000) .

1. Continue Refer to «VERIFICATION»(ref-476747-S24343962222012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reinstall the connectors, components etc.
3. Ignition on
4. Check that the air flow is correct. The value must be approximately 0 kg/h with the engine switched off
5. Start the engine. Read off the air flow. The value may vary by between 12-20 kg/h at idle speed, depending on the engine load and temperature. The value may be in excess of 20 kg/h if the engine is cold
6. Increase the engine speed (RPM) and check that the air flow increases with increased engine speed.

Are the values correct?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S03924334592012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reinstall the connectors, components etc.
3. Ignition on
4. Check that the air flow is correct. The value must be approximately 0 kg/h with the engine switched off
5. Start the engine. Read off the air flow. The value may vary by between 12-20 kg/h at idle speed, depending on the engine load and temperature. The value may be in excess of 20 kg/h if the engine is cold
6. Increase the engine speed (RPM) and check that the air flow increases with increased engine speed.

Are the values correct?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S10733745552012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

HEATED OXYGEN SENSORS (HO2S)

Front heated oxygen sensor (HO2S)

Scheme 45

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 (Volvo scan tool) can be used to read off the calculated lambda value from the heated oxygen sensor.

Rear heated oxygen sensor (HO2S)

Scheme 46

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 (Volvo scan tool).

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 47

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 (Volvo scan tool).

Scheme 48

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 (Volvo scan tool).

Scheme 49

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 (Volvo scan tool).

OUTSIDE TEMPERATURE SENSOR

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 (Volvo scan tool).

Scheme 50

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 (Volvo scan tool).

Scheme 51

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) 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 52

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 53

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 54

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 55

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.

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

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 56

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 whilst 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 (Volvo scan tool).

Scheme 57

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 (Volvo scan tool).

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 58

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 (Volvo scan tool).

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

Scheme 59

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 (Volvo scan tool).

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 60

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 sparkplug wells above each spark plug.

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

Scheme 61

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 62

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 (Volvo scan tool).

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

Scheme 63

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 (Volvo scan tool).

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 64

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 (Volvo scan tool).

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

IDENTIFYING UPGRADED SOFTWARE ECM/ETM

Upgraded software for the engine control module (ECM) and electronic throttle module (ETM), available during 2006 or later, can be identified. The updated software has a diagnostic number/software number . The diagnostic number/software number can be read using VIDA (Volvo scan tool).

The differences between the first version , which is identified by the software number, and the second version , which is identified by the diagnostic number, include the following

1. Improved driveability after engine control module (ECM) reset. The start values for some system adaptations are adjusted to facilitate handling of aged/worn systems/components after diagnostic trouble code deletion or when the control module has been without power.
2. Increased hardiness to certain combinations of aging/wear in the system. The work areas for some adaptations are adjusted to better match the aging of certain components.
3. Supplements as to which faults are to generate a message to the driver.
4. Improved serviceability (diagnostic trouble code generation) for some intermittent faults that generate driveability problems.

The diagnostic number (also known as diagnostic version in VIDA (Volvo scan tool)) and the software number can be read out via VIDA (Volvo scan tool). The electronic throttle module (ETM) is identified solely by the diagnostic number.

If the diagnostic number/software number is within the following series, it is the latest software downloaded

1. 5-cyl non-turbo engines ,: Engine control module (ECM) diagnostic number 30785129 - 30785132 or 30785667 and electronic throttle module (ETM) 30785387.
2. Turbocharged and 6-cylinder normally aspirated engines : First version, engine control module (ECM) software number 30785203 - 30785240 and electronic throttle module (ETM) diagnostic number 30785388. Second version, engine control module (ECM) diagnostic number 30785372 - 30785378 and electronic throttle module (ETM) diagnostic number 30785388.

Scheme 65

The engine control module (ECM) controls the camshaft reset valve (CVVT) steplessly. The pressure of the engine oil is used to regulate the CVVT unit.

The CVVT is installed on the intake camshaft on all B5244 engines.

There are 30 camshaft degrees (60 crankshaft degrees) between the limit positions.

The variable camshaft is hydraulically controlled by the engine oil. The camshaft turns when the camshaft reset valve (CVVT) releases lubricating oil into the front (A) or rear chamber (B) of the CVVT unit. The chambers are separated by a piston which is secured in the camshaft. The piston is secured in the cover of the CVVT unit by splines so that it moves easily. When the oil acts on the piston, the piston twists. The pulse wheel for the timing belt is on the outer cover of the CVVT unit.

Regulation is precise and rapid.

The camshaft reset valve (CVVT) has extremely fine ducts. This allows for precise regulation. However as a result the reset valve is sensitive to contaminants.

The main role of the variable camshaft is to reduce exhaust emissions, especially during cold starting. Idle quality is also improved.

Before the engine starts, there is an internal check consisting of the following stages

1. When the ignition is switched on, there is an electrical check of the signal cable, the power supply cable and the solenoid. This check checks for a short-circuit to supply voltage or ground and open-circuits
2. The camshaft is checked to ensure that it is in the correct position in relation to the flywheel, with the camshaft in its 0 position (mechanical resting position). This can be done by comparing the signals from the camshaft position (CMP) sensor and the engine speed (RPM) sensor. If there is too much deviation between these, the camshaft reset valve (CVVT) is not activated and a diagnostic trouble code (DTC) is stored
3. During greater control of the variable camshaft, the amount of time taken to deploy the camshaft to the desired value is measured. This time is used partly to assess how long it takes to change the angle of the camshaft and partly to disengage the variable camshaft if the time exceeds a certain maximum limit. The camshaft uses the engine oil and the oil pressure to turn itself. The rotation time varies, depending on factors such as engine speed (RPM), oil pressure and the viscosity of the oil (which depends open the temperature and quality of the oil)
4. The signal from the camshaft position (CMP) sensor is compared with the signal from the engine speed (RPM) sensor when the engine is turned over to ensure that it is correct. The check stops when the engine has started. If the check returns faulty values, a diagnostic trouble code (DTC) is stored and there is no camshaft control (CVVT).

Control

Scheme 66

Control takes place as follows when deploying the camshaft

1. Oil is forced from the engine lubricating system to the intake port on the reset valve
2. The engine control module (ECM) grounds the valve, the position of the piston in the valve changes and the oil is guided to the continuous variable valve timing (CVVT) unit chamber (A1) via the duct (A2) in the camshaft
3. The continuous variable valve timing (CVVT) unit hub is pressed backwards by the oil pressure. The continuous variable valve timing (CVVT) unit then rotates the hub and the carriers are joined by twisted splines
4. The oil flows to the engine sump via the outer ducts on the hub and the reset valve's return hose.

Control takes place as follows when returning the camshaft

1. Oil is forced from the engine lubricating system to the intake port on the reset valve
2. The engine control module (ECM) breaks the ground connection for the valve. The piston in the valve is then pressed back by a spring. The oil flows to the continuous variable valve timing (CVVT) unit chamber (B1) via a duct (B2) in the camshaft
3. The hub of the continuous variable valve timing (CVVT) unit is forced forward by the oil pressure that is created. The continuous variable valve timing (CVVT) unit will rotate back to the non-deployed position
4. The oil flows to the engine oil sump via the center duct on the hub and the reset valve's return duct.

The above takes place very quickly. The engine control module (ECM) controls the deployment and return of the reset valve continually at high frequency. This results in rapid and exact control.

There are diagnostics for this function.

Scheme 67

Knock occurs in the combustion chamber when the fuel and air mixture self ignites. This can occur either before or after the spark plug has produced an ignition spark. In both cases the gas in two or more places ignites in the combustion chamber.

This results in an extremely fast combustion process with flames from several directions. When these flames collide, the pressure in the cylinder increases rapidly and there is a mechanical knocking sound.

If any of the cylinders knock there is a specific type of vibration in the cylinder block. These vibrations are transferred to the knock sensors (KS) which are screwed into place in the cylinder block. The resultant mechanical stress in the piezo electrical material in the knock sensors generates a voltage. The engine control module (ECM) can then determine which cylinder is knocking with the help of the camshaft position (CMP) sensor and the engine speed (RPM) sensor.

The knock sensors (KS) also interpret a proportion of normal engine sound. The control module is able to recognize the vibrations which correspond to knocking by filtering, amplifying and using software to evaluate the signal.

If the knock sensors (KS) detect knocking in the engine above a certain threshold value, the ignition timing is first retarded and then the fuel / air mixture is enriched to eliminate knocking.

Scheme 68

The following components are used for ignition control

1. engine speed sensor (7/25)
2. camshaft position (CMP) sensor (7/172)
3. mass air flow (MAF) sensor (7/17)
4. engine coolant temperature (ECT) sensor (7/16)
5. electronic throttle module (ETM) (4/50)
6. knock sensor (KS) (7/23-7/24)
7. transmission control module (TCM) (4/28)
8. spark plugs with ignition coils (20/3-20/8)
9. brake control module (BCM)/anti-lock brake system module (ABS), (4/16).

The engine control module (ECM) calculates the optimum ignition advance based on the software and information from the sensors. The engine control module (ECM) cuts the current to the ignition coil mounted on the cylinder to be ignited and produces a spark.

During the starting phase the engine control module (ECM) produces a fixed ignition setting. When the engine starts and the car is driven the engine control module (ECM) calculates the optimum ignition setting according to the engine speed (RPM), load, temperature etc.

The engine control module (ECM) analyses the signal from the knock sensors (KS) when the engine reaches operating temperature. If any of the cylinders knock, the ignition is retarded for that specific cylinder until the knocking ceases.

The ignition then advanced to the normal position or until the knock recurs.

Before the gearbox control module (TCM) changes gear, it sometimes transmits a torque limiting request to the engine control module (ECM). The engine control module (ECM) then retards the ignition momentarily to reduce the torque, resulting in smoother gear changes and reducing the load on the gearbox. There are different ignition retardation levels depending on the signals from the gearbox control module (TCM). The return signal from the engine control module (ECM) to the gearbox control module (TCM) confirms that the signal reached the engine control module (ECM). The brake control module (BCM)/ABS control module transmits information to the engine control module (ECM) about deviations in the drive line. The signal is used to stop the diagnosis.

For further information, also, see MISFIRE DIAGNOSTIC .

The engine misfires if the fuel does not ignite correctly. See MISFIRE DIAGNOSTIC .

Scheme 69

The cruise control function is an example of distributed functionality.

The following components are used when driving using cruise control

1. engine control module (ECM).
2. electronic throttle module (ETM)
3. brake control module (BCM) / anti-lock brake system module (ABS)
4. accelerator pedal (AP) position sensor
5. clutch pedal sensor
6. brake pedal sensor
7. control unit cruise control
8. steering wheel module (SWM)
9. central electronic module (CEM)
10. gearbox control module (TCM)
11. driver information module (DIM).

To activate cruise control the function must be switched on using the "CRUISE" button. A lamp lights up in the Driver Information Module (DIM).

The driver activates the function by pressing the SET+ or SET- button. A message is then transmitted via the low speed side of the Controller area network (CAN) to the central electronic module (CEM) which then transmits the message on via the high speed side of the Controller area network (CAN) to the engine control module (ECM). The engine control module (ECM) uses the vehicle speed signal from the brake control module (BCM)/ABS control module to control the throttle angle so that a constant speed is maintained. The gearbox control module (TCM) also receives a message indicating that cruise control is active via the Controller area network (CAN), so that the gearbox follows certain shifting patterns when the cruise control is active.

If the accelerator pedal (AP) is depressed the speed increases as normal and then resumes to the stored value when the driver releases the accelerator pedal (AP) again.

The engine control module (ECM) continually stores the speed. If the cruise control is disengaged, if for example the driver presses the brake pedal, the previous stored speed can be used by pressing the "RESUME" button.

Cruise control cannot be activated at speeds below 35 km/h.

Cruise control is disengaged

1. when the driver presses the clutch pedal or brake pedal
2. when the driver presses the "CRUISE" button on the steering wheel
3. when the driver depresses the "0" button on the steering wheel
4. if "P" or "N" positions are transmitted on the Controller area network (CAN) (applies to automatic transmissions)
5. if the speed deviates too much from the set value
6. when certain diagnostic trouble codes (DTCs) are stored which do not allow continued activation (For further information, see diagnostic trouble code (DTC) information).

Scheme 70

Note. This service information pertains to the air flow adaptation over the throttle unit, not to be confused with the control module's fuel adaptation (lambda adaptation).

There is a correction factor in the Engine control module (ECM) for adjusting the leakage flow over the throttle unit. Leakage flow means the air that does not go through the throttle unit, but goes via the crankcase ventilation, power brake booster and EVAP system. For the control module to be able to learn the adjustments needed in the different air flow areas, there are two adaptation areas. One for idling and one for part load. These values are saved when the engine is switched off.

These values can be read off using the "Air mass, correction value" and "Leakage flow over throttle unit" parameters.

AIR-LEAKAGE: FLOW VIA THROTTLE UNIT

HINT: The following measurement for diagnostic trouble code (DTC) ECM-130A can be carried out to determine the fault cause.

Air flow adaptation idling

The parameter for air flow adaptation idling is one of the parameters for determining the leakage flow over the throttle unit where the mass air flow (MAF) sensor flow determines the reference value. The adaptation value is the value that must be added or subtracted from the control module calculated air flow. The calculated air flow added or subtracted from the adaptation value should be the same as the mass air flow (MAF) sensor's flow.

The adaptation value is not used as a part of a diagnostic function and will not, in the event of a large value, result in a diagnostic trouble code (DTC). The value can be used to evaluate the air flow over the throttle unit. The adaptation value is displayed in kg/h and the normal values are 5-10 kg/h.

The engine does not only obtain air via the throttle unit, but also from the crankcase ventilation, the EVAP system and power brake booster for example. The total of this air supply should give us our normal adaptation value of 5-10 kg/h, which does not pass through the throttle unit and therefore the mass air flow (MAF) sensor.

If this air supply is removed or slightly restricted, e. g. if the crankcase ventilation becomes blocked, the adaptation value drops to less than 5 kg/h. Dirt in the throttle unit can have the same effect and generally depends on the crankcase ventilation being blocked. The crankcase ventilation should, in such cases, be checked first. If there is an air leak in the intake manifold the value would increase to above 10 kg/h.

Air flow adaptation part load

This is the part of air flow adaptation that makes it possible to compensate for the tolerance interval between different engines and for aging components. The normal value without adaptation is 1. A value below 1, e. g. 0.95 indicates that more air passes through the mass air flow (MAF) sensor than calculated. An indication of a blocked crankcase ventilation is a low adaptation value around 0.85 or less.

A value greater than 1 can indicate an air leak inside the intake manifold where, for example, a loose or defective vacuum line can give a value of 1.15 or greater.

Diagnostic trouble code (DTC) ECM-130A is stored if the value for the air flow adaptation at part load and the correction factor are extremely large. Unfortunately, the correction factor cannot be displayed in VIDA (Volvo scan tool), but if this DTC has been generated, the correction factor can be assumed to be extremely large. These adaptations should not only be used for fault-tracing, but considered to be an indication of which method should be used next time.

The fuel adaptations (lambda adaptations) should be checked first to analyze for an air leak. Thereafter check for smaller leaks than normal, for idling, less than 5 kg/h and/or for part load less than 1 kg/h. If the leakage flow is smaller, the crankcase ventilation may be blocked.

If the leakage flow is greater than normal, for idling greater than 10 kg/h and/or for part load greater than 1 kg/h, there might be an air leak in the connections to the engine after the throttle unit.

Check that the hoses and hose connectors between the mass air flow (MAF) sensor and the throttle unit are not leaking or defective.

Check that the boost pressure sensor is correctly mounted. Check for air leakage around the component.

HINT: This diagnostic trouble code can be caused by a damaged mass air flow sensor.

Remedy as necessary.

Other information

1. see «CHECK FOR AIR LEAKS IN THE INTAKE SYSTEM»(ref-494823-S24990024732012081600000)
2. For B5xx4T, see «THROTTLE BODY (TB), CLEANING»(ref-476750-S36382112932012060500000) .
3. For B6xx4x, see «THROTTLE BODY (TB), CLEANING»(ref-476750-S05163330712012060500000) .
4. see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000)

1. Continue Refer to «VERIFICATION»(ref-476747-S06825102182012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off.
2. Reinstall the connectors, components etc.
3. Ignition on.
4. Read off and make a note of the adaptation value.
5. Start the engine. Increase the engine speed (RPM) a couple of times.
6. Read off the adaptation value and check that the adaptation value approaches 1.

Does the adaptation value approach 1?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S14029658732012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

see SIGNAL TOO HIGH

see SIGNAL TOO HIGH

see SIGNAL TOO LOW

see SIGNAL TOO LOW

see FAULTY SIGNAL

see FAULTY SIGNAL

1. Ignition off
2. Check the boost pressure sensor connector and terminal. Check for contact resistance and oxidation. NOTE: The intake air temperature (IAT) sensor is integrated in the boost pressure sensor. If no errors are found and the fault is permanent, replace the intake air temperature (IAT) sensor. Remedy as necessary. Other information: see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000) For resistance values: «COMPONENT SPECIFICATIONS»(ref-476694-S25701556572012060500000) For B5xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000) For B6xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000)

1. Continue Refer to «VERIFICATION»(ref-476747-S37180958342012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Start the engine. Allow the engine to idle for 5 minutes
4. Read off diagnostic trouble codes (DTCs). The fault has been remedied if status of the diagnostic trouble code (DTC) is intermittent.

Is the status of the diagnostic trouble code (DTC) intermittent?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S41698335462012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

SIGNAL TOO HIGH / SIGNAL TOO LOW

see SIGNAL TOO HIGH / SIGNAL TOO LOW

see SIGNAL TOO HIGH / SIGNAL TOO LOW

see SIGNAL TOO HIGH / SIGNAL TOO LOW

CHECKING THE STATUS

Check whether the fault is permanent or intermittent by reading the signals from the fuel, outside and engine temperature sensors.

Note. In order for the correct values to be shown, reading of the temperatures must take place at the moment of start.

1. Start the engine.

Check that the intake temperature is reasonable. The temperature must correspond to the ambient temperature.

The fault is permanent if the signal is incorrect. The fault is intermittent if the signal is correct.

HINT: Remove the air temperature sensor, but let the connector remain connected. Let the hood remain open, the sensor should then indicate the same temperature as the outdoor temperature.

1. Continue Refer to «CHECKING THE COMPONENT AND WIRING»(ref-476747-S33097227372012060500000)

Scheme 71

Scheme 72

1. Ignition off.
2. Unplug the air temperature sensor connectors.
3. Check the connectors. Check for loose connections. Check for contact resistance. Check for oxidation. Check the resistance of the sensor between #1 and #2 (to the sensor). Remedy as necessary. Other information see «CONNECTING THE BREAKOUT BOX»(ref-476691-S38062545372012060500000) For 5 cylinder turbocharged engines -2004, see «SIGNAL DESCRIPTION»(ref-476694-S26303328522012060500000) For 5 cylinder turbocharged engines 2005-, see «SIGNAL SPECIFICATION»(ref-476694-S29505181092012060500000) . see «COMPONENT SPECIFICATIONS»(ref-476694-S25701556572012060500000) For B5xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000) For B6xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17655503092012060500000)

1. Continue Refer to «VERIFICATION»(ref-476747-S37378043432012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Ignition on. Read off the air temperature sensor signal. Check that the signal is plausible, compare with the external temperature.

Is the value OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S02780104662012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

FAULT-TRACING

see FAULT-TRACING

see SIGNAL TOO HIGH

see SIGNAL TOO HIGH

see SIGNAL TOO LOW

see SIGNAL TOO LOW

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off.
2. Reconnect connectors, reinstall components.
3. Ignition on.
4. Read off outside temperature.

Is the temperature within its permitted range?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S26915027832012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

FAULTY SIGNAL OR SIGNAL MISSING

see FAULTY SIGNAL OR SIGNAL MISSING

see FAULTY SIGNAL OR SIGNAL MISSING

see FAULTY SIGNAL OR SIGNAL MISSING

INFORMATION

No fault-tracing has been developed for this diagnostic trouble code (DTC). The diagnostic trouble code (DTC) for this fault is first stored in the Central electronic module (CEM), then in the Engine control module (ECM). This diagnostic trouble code (DTC) can not be erased before the diagnostic trouble codes (DTC) in the central electronic module (CEM) has been remedied and erased.

Therefore, first read off diagnostic trouble codes in Central electronic module (CEM), perform troubleshooting and perform actions as needed. This diagnostic trouble code (DTC) can then be erased.

For further information on this diagnostic trouble code, see Diagnostic trouble code (DTC) information.

see FAULT-TRACING INFORMATION

There is no fault-tracing for this diagnostic fault code (DTC).

For further information on this diagnostic trouble code, see Diagnostic trouble code (DTC) information.

see FAULT-TRACING INFORMATION

1. Ignition off. Check the boost pressure sensor connector. Check for contact resistance and oxidation. Check that the boost pressure sensor is correctly installed and has not come loose. HINT: The fault may be due to a defective boost pressure sensor. The boost pressure sensor may be defective if the above fault tracing and corrective action does not remedy the fault. Remedy as necessary. Other information: For B5xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000) For B6xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000) .

1. Continue Refer to «VERIFICATION»(ref-476747-S35297883742012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

Scheme 73

1. Reinstall the connectors, components etc.
2. Test drive the car to reach different boost pressures
3. Read off the diagnostic status and the fault status for diagnostic trouble code (DTC) ECM-1600. NOTE: Do not switch off the engine before VCT2000 (or appropriate scan tool) has been connected and the status of the fault has been read off. Check that the fault status is "NO FAULT FOUND" when the diagnostic status is COMPLETED. If the fault status is "FAULT FOUND" when the diagnostic status is COMPLETED there is a fault.

Is the fault status "NO FAULT FOUND"?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S31277920092012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

1. Ignition off
2. Check the boost pressure sensor connector. Check for contact resistance and oxidation
3. Reinstall the components, reconnect the connectors etc.
4. Ignition on
5. Read off the boost pressure sensor signal. Check that the signal is within its permitted range. With the engine switched off, the voltage should be approximately 1.9 V. If the signal is now OK, the fault was caused by poor contact in the connector. Other information: For B5xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000) For B6xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000) see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000) .

Is the signal OK?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «CHECKING COMPONENTS AND WIRING»(ref-476747-S38155734062012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reinstall the connectors, components etc.
3. Ignition on
4. Read off the boost pressure sensor signal. With the ignition on the voltage should be approximately 1.9 V.

Is the signal OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S33859364402012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reinstall the connectors, components etc.
3. Ignition on
4. Read off the boost pressure sensor signal. With the ignition on the voltage should be approximately 1.9 V.

Is the signal OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S27534125952012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

1. Ignition off
2. Check the boost pressure sensor connector. Check for contact resistance and oxidation
3. Reinstall the components, reconnect the connectors etc.
4. Ignition on. Read off the boost pressure and the atmospheric pressure. The difference in pressure must not be greater than 140 hPa. If the difference is less than 140 hPa, the cause of the fault was loose connections in the connector. Other information: For B5xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000) For B6xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000)

Is the difference between the pressures less than 140 hPa?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «REPLACING THE COMPONENT»(ref-476747-S22554020572012060500000)

If the difference between the pressures is greater than 140 hPa, try replacing the boost pressure sensor.

HINT: Normal atmospheric pressure is 1013 hPa. Check which of the sensors appears to display the incorrect reading.

If the fault is not in the boost pressure sensor, replace the engine control module (ECM).

Note. The atmospheric pressure sensor is built into the engine control module (ECM) and therefore cannot be replaced as a separate item.

Remedy as necessary.

Other information

1. Normal atmospheric pressure is 1013 hPa
2. For B5xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000)
3. For B6xx4T, see «TEMPERATURE AND PRESSURE SENSORS, REPLACING»(ref-476695-S35429283012012060500000)
4. To access or replace the engine control module (ECM), see «ENGINE CONTROL MODULE (ECM), REPLACING»(ref-476695-S16000409902012060500000)
5. For 5 cylinder turbocharged engines -2004, see «SIGNAL DESCRIPTION»(ref-476694-S26303328522012060500000)
6. For 5 cylinder turbocharged engines 2005-, see «SIGNAL SPECIFICATION»(ref-476694-S29505181092012060500000) .
7. For 6 cylinder engines -2004, see «SIGNAL SPECIFICATION»(ref-476694-S39196199822012060500000)
8. For 6 cylinder engines 2005-, see «SIGNAL SPECIFICATION»(ref-476694-S31890965202012060500000) .

1. Continue Refer to «VERIFICATION»(ref-476747-S22703393112012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reinstall the connectors, components etc.
3. Ignition on
4. Read off the boost pressure sensor pressure and atmospheric pressure sensor pressure
5. The difference between the pressure sensors should not be greater than 140 hPa.

Is the difference between the pressure sensors less than 140 hPa?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S16533853732012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

CHECKING THE ENGINE COOLANT TEMPERATURE (ECT)

1. Fault-tracing must begin with the engine cold (+20 °C) so that the engine coolant temperature (ECT) sensor can be tested over as wide a temperature range as possible
2. Switch off the climate control system
3. Start the engine. Read off the engine coolant temperature (ECT). Check that the engine coolant temperature (ECT) is within its permitted range and corresponds with the engine warming up.

Is the temperature reasonable?

1. YES Refer to «CHECKING THE THERMOSTAT»(ref-476747-S31399776342012060500000)
2. NO Refer to «REPLACING THE COMPONENT»(ref-476747-S35979401002012060500000)

CHECKING THE THERMOSTAT

1. Start the engine. Run the engine until the engine coolant temperature (ECT) reaches approximately 100 °C
2. Activate the engine cooling fan (FC) with the engine running
3. Wait approximately 90 seconds and then shut-off the engine cooling fan (FC). Read off the engine coolant temperature (ECT). If the temperature is 85 °C or lower when the fan stops, the thermostat is defective.

Is the temperature lower than 86 °C?

1. YES Refer to «REPLACING THE COMPONENT»(ref-476747-S21538983752012060500000)
2. NO FAULT TRACING FAILED: The fault should have been detected and remedied. As this is not the case fault-tracing has failed. Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Try a new thermostat. See THERMOSTAT, REPLACING .

Scheme 74

Try a new engine coolant temperature (ECT) sensor.

1. For B5xx4T, see «REPLACING THE THERMOSTAT AND/OR ENGINE COOLANT TEMPERATURE SENSOR»(ref-476760-S13127344692012060500000)
2. For B6xx4T, see «ENGINE COOLANT TEMPERATURE (ECT) SENSOR, REPLACING»(ref-476695-S19968063362012060500000) .

1. Continue Refer to «VERIFICATION»(ref-476747-S00792864022012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Fault-tracing must begin with the engine cold (+20 °C) so that the engine coolant temperature (ECT) sensor can be tested over as wide a temperature range as possible
2. Ignition off
3. Reconnect connectors, reinstall components etc.
4. Start the engine
5. Read off the engine coolant temperature. Check that the engine coolant temperature (ECT) is within its permitted range and corresponds with the engine warming up.

Is the temperature within its permitted range?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S03488543502012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

If the fault is intermittent, do not verify fault-tracing if the fault does not recur.

It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).

1. Fault-tracing must begin with the engine cold (+20 °C) so that the engine coolant temperature (ECT) sensor can be tested over as wide a temperature range as possible
2. Switch off the climate control unit
3. Start the engine. Read off the engine coolant temperature (ECT). Check that the engine coolant temperature (ECT) is within its permitted range and corresponds with the engine warming up.

Is the temperature within its permitted range?

1. YES Refer to «CHECKING THE THERMOSTAT»(ref-476747-S13844684332012060500000)
2. NO Refer to «REPLACING THE COMPONENT»(ref-476747-S08443274482012060500000)

1. Start the engine. Run the engine until the engine coolant temperature (ECT) reaches approximately 100°C
2. Activate the engine cooling fan (FC) with the engine running
3. Wait approximately 90 seconds and then shut-off the engine cooling fan (FC). Read off the engine coolant temperature (ECT). If it is 85°C or lower when the fan stops, the thermostat is defective.

Is the temperature lower than 86°C?

1. YES Refer to «REPLACING THE COMPONENT»(ref-476747-S21263692522012060500000)
2. NO FAULT TRACING FAILED: The fault should have been detected and remedied. As this is not the case fault-tracing has failed. Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Try a new thermostat. See THERMOSTAT, REPLACING .

Try a new engine coolant temperature (ECT) sensor.

1. For B5xx4T, see «REPLACING THE THERMOSTAT AND/OR ENGINE COOLANT TEMPERATURE SENSOR»(ref-476760-S13127344692012060500000)
2. For B6xx4T, see «ENGINE COOLANT TEMPERATURE (ECT) SENSOR, REPLACING»(ref-476695-S19968063362012060500000) .

1. Continue Refer to «VERIFICATION»(ref-476747-S12977322842012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Fault-tracing must begin with the engine cold (+20 °C) so that the engine coolant temperature (ECT) sensor can be tested over as wide a temperature range as possible
2. Ignition off
3. Reconnect connectors, reinstall components etc.
4. Start the engine
5. Read off the engine coolant temperature. Check that the engine coolant temperature (ECT) is within its permitted range and corresponds with the engine warming up.

Is the temperature within its permitted range?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S27943370782012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

THERMOSTAT, REPLACING

REMOVING THE THERMOSTAT

Scheme 75

Remove

1. the clamp holding the return hose for the power steering
2. the screw holding the engine stabilizer brace to the bracket on the engine
3. the screws holding the engine stabilizer brace to the suspension turrets
4. the engine stabilizer brace
5. the expansion tank cap.

Raise the car. Remove the lower splashguard.

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

Close the cock.

Install the lower splash guard.

Lower the car.

Scheme 76

1. the plastic hoses between the turbocharger (TC) / charge air cooler and the air cleaner (ACL) / turbocharger (TC). Applies only to B6xx4T engines .

Scheme 77

Lift up the servo reservoir and place it on top of the engine.

Note. Ensure that the timing belt cover has cleared the nipple on the thermostat housing before the cover is pulled up.

Remove

1. the screw for the front timing belt cover. Applies only to B6xx4T Cars with chassis number 203779- see «TIMING COVER FRONT, REPLACING»(ref-476755-S02493621522012060500000) .
2. the timing belt cover. Use a weatherstrip tool.

Scheme 78

1. the thermostat housing cover
2. the thermostat.

INSTALLING THE THERMOSTAT

Note. Clean all mating surfaces. Ensure that no dirt enters the fluid ducts.

Note. Ensure that the timing belt cover is in position before the cover is pressed in against the rear timing belt cover to prevent damage to the nipple on the thermostat housing.

Install

1. the new thermostat
2. the cover of the thermostat housing with a new gasket . Tighten to 17 Nm
3. the front timing belt cover. The mudguard over the right drive shaft boot may come loose. If this happens, secure it from underneath
4. the screw for the front timing belt cover. Tighten to 12 Nm . Applies only to B6xx4T Cars with chassis number 203779- see «INSTALLING THE FRONT TIMING COVER»(ref-476755-S27397020582012060500000) .

1. the plastic hoses between the turbocharger (TC) / charge air cooler and the air cleaner (ACL) / turbocharger (TC). Applies only to B6xx4T engines .

1. the servo reservoir. Check that the hoses are correctly positioned
2. the engine stabilizer brace
3. the screws holding the engine stabilizer brace to the suspension turrets. Tighten to 50 Nm
4. the screw holding the engine stabilizer brace to the bracket on the engine. Tighten to 80 Nm
5. the clamp holding the return hose for the power steering.

Carry out a function test

Fill with coolant.

Install the cap on the expansion tank.

Test drive the engine until the thermostat has opened.

Top up the coolant if necessary.

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect connectors, reinstall components etc.
3. Ignition on
4. Read off the engine coolant temperature (ECT) sensor.

Is the temperature within its permitted range?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S09852556762012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

If the fault is intermittent, do not verify fault-tracing if the fault does not recur.

It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Ignition on
4. Read off the engine coolant temperature (ECT) sensor.

Is the temperature within its permitted range?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S12489002212012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

1. Ignition off
2. Check the connector on the engine coolant temperature (ECT) sensor. Check for contact resistance and oxidation
3. Reinstall the components, reconnect the connectors etc.
4. Ignition on
5. Read off the engine coolant temperature (ECT) sensor. If the temperature is now within its permitted range, the fault was caused by loose connections in the connector. Other information see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000) For B5xx4T, see «REPLACING THE THERMOSTAT AND/OR ENGINE COOLANT TEMPERATURE SENSOR»(ref-476760-S13127344692012060500000) For B6xx4T, see «ENGINE COOLANT TEMPERATURE (ECT) SENSOR, REPLACING»(ref-476695-S19968063362012060500000) .

Is the temperature within its permitted range?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «CHECKING THE WIRING AND COMPONENT»(ref-476747-S35236775282012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect connectors, reinstall components etc.
3. Ignition on
4. Read off the engine coolant temperature (ECT) sensor.

Is the temperature within its permitted range?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S42623166242012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

If the fault is intermittent, do not verify fault-tracing if the fault does not recur.

It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).

1. Ignition off
2. Check the engine coolant temperature (ECT) sensor connector. Check for contact resistance and oxidation
3. Reinstall the components, reconnect the connectors etc.
4. Ignition on
5. Read off the engine coolant temperature (ECT) sensor. If the temperature is now within its permitted range, the fault was caused by loose connections in the connector. Other information For B5xx4T, see «REPLACING THE THERMOSTAT AND/OR ENGINE COOLANT TEMPERATURE SENSOR»(ref-476760-S13127344692012060500000) For B6xx4T, see «ENGINE COOLANT TEMPERATURE (ECT) SENSOR, REPLACING»(ref-476695-S19968063362012060500000) . see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000) .

Is the temperature within its permitted range?

1. YES OKAY: Troubleshooting has been completed.
2. NO Refer to «CHECKING THE WIRING AND COMPONENT»(ref-476747-S35473469502012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Ignition on
4. Read off the engine coolant temperature (ECT) sensor.

Is the temperature within its permitted range?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S32419712662012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect connectors, reinstall components etc.
3. Ignition on
4. Activate the relevant injector. A "click" should be heard when the injector is activated.

Is the injector working?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S07360223392012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect connectors, reinstall components etc.
3. Ignition on
4. Activate the relevant injector. A "click" should be heard when the injector is activated.

Is the injector working?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S40651656622012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect connectors, reinstall components etc.
3. Ignition on
4. Activate the relevant injector. A "click" should be heard when the injector is activated.

Is the injector working?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S14490014612012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

REPLACING THE THERMOSTAT

Note. This diagnostic trouble code (DTC) is stored if the engine coolant temperature (ECT) sensor freezes. This may happen if the coolant level is low or there is too little glycol in the coolant. Check the engine coolant level and its freezing point. Remedy as necessary.

The engine control module (ECM) has registered that the actual temperature increase has deviated from the calculated temperature increase. This deviation is due to a defective thermostat.

Try replacing the thermostat.

1. For B5xx4T, see «REPLACING THE THERMOSTAT AND/OR ENGINE COOLANT TEMPERATURE SENSOR»(ref-476760-S13127344692012060500000)
2. For B6xx4T, see «ENGINE COOLANT TEMPERATURE (ECT) SENSOR, REPLACING»(ref-476695-S19968063362012060500000) .

1. Continue Refer to «INFORMATION»(ref-476747-S38823212312012060500000)

In case of this defect, troubleshooting is not followed by verification.

The information can be displayed again or the fault-tracing for this fault can be interrupted.

CHECKING THE FUEL INJECTION SYSTEM

Check the intake system for air leakage.

HINT: Air leakage in the intake system can occur through the evaporative emission system (EVAP) valve, the secondary air solenoid valve or the power brake booster.

Check the fuel pressure.

Test drive the car for approximately 10 minutes.

Check the mass air flow (MAF) sensor. Read off its correction factor. The value must be between 0.8 and 1.2.

Note. There must not be any air leakage when this test is carried out.

Remedy as necessary.

Other information

1. see «CHECK FOR AIR LEAKS IN THE INTAKE SYSTEM»(ref-494823-S24990024732012081600000)
2. see «CHECKING FUEL AND RESIDUAL PRESSURES»(ref-494826-S19525701392012081600000)
3. see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000)

1. Continue Refer to «VERIFICATION»(ref-476747-S36874029782012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Test drive the vehicle on the road. Run a TRIP schedule so that the engine control module (ECM) compares the diagnostics. To run a TRIP schedule, see: «VERIFYING REPAIRS»(ref-494828-S19905032792012081600000)
4. Connect VCT2000 (or appropriate scan tool) to the data link connector (DLC) without switching off the engine. NOTE: If the engine is switched off, the stored fault status will be erased and the test drive will have to be repeated. Read off the diagnostic status and fault status for the diagnostic trouble code (DTC) by selecting the relevant diagnostic trouble code (DTC) from the list. Check the fault status for the diagnostic trouble code (DTC) when the diagnostic is "Complete". If the function is correct, the fault status must be "No fault found" when the diagnostic is complete.

Is the function OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S25694322382012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

see SIGNAL TOO HIGH

Check the intake system for air leakage.

HINT: Air leakage in the intake system can occur through the evaporative emission system (EVAP) valve, the secondary air solenoid valve or the power brake booster.

Check the exhaust system for leakage.

Check the fuel pressure and residual pressure.

Check that the oil level is within the minimum and maximum markings.

Check the viscosity of the engine oil by reading off the short-term fuel trim with the engine running. Plug the crankcase ventilation and read off the short-term fuel trim again. The value must be more or less unchanged.

Remedy as necessary.

Other information

1. see «CHECK FOR AIR LEAKS IN THE INTAKE SYSTEM»(ref-494823-S24990024732012081600000)
2. see «CHECKING FOR AIR LEAKAGE IN THE EXHAUST SYSTEM»(ref-494824-S07275287112012081600000)
3. see «CHECKING FUEL AND RESIDUAL PRESSURES»(ref-494826-S19525701392012081600000)

Was a fault detected?

1. YES Refer to «VERIFICATION»(ref-476747-S39082310202012060500000)
2. NO Refer to «CHECKING THE MASS AIR FLOW (MAF) SENSOR»(ref-476747-S33624671222012060500000)

CHECKING THE MASS AIR FLOW (MAF) SENSOR

Test drive the car for approximately 10 minutes.

Read off the correction factor of the mass air flow (MAF) sensor. The value must be between 0.8 and 1.2.

Note. There must not be any air leakage when this test is carried out.

Remedy as necessary.

Other information

1. see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000) .

1. Continue Refer to «VERIFICATION»(ref-476747-S39082310202012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Test drive the vehicle on the road. Run a TRIP schedule so that the engine control module (ECM) compares the diagnostics. To run a TRIP schedule, see: «VERIFYING REPAIRS»(ref-494828-S19905032792012081600000)
4. Connect VCT2000 (or appropriate scan tool) to the data link connector (DLC) without switching off the engine. NOTE: If the engine is switched off, the stored fault status will be erased and the test drive will have to be repeated. Read off the diagnostic status and fault status for the diagnostic trouble code (DTC) by selecting the relevant diagnostic trouble code (DTC) from the list. Check the fault status for the diagnostic trouble code (DTC) when the diagnostic is "Complete". If the function is correct, the fault status must be "No fault found" when the diagnostic is complete.

Is the function OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S23445145372012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

see SIGNAL TOO LOW

Check the intake system for air leakage.

HINT: Air leakage in the intake system can occur through the evaporative emission system (EVAP) valve, the secondary air solenoid valve or the power brake booster.

Check the fuel pressure.

Test drive the car for approximately 10 minutes.

Check the mass air flow (MAF) sensor. Read off its correction factor. The value must be between 0.8 and 1.2.

Note. There must not be any air leakage when this test is carried out.

Remedy as necessary.

Other information

1. see «CHECK FOR AIR LEAKS IN THE INTAKE SYSTEM»(ref-494823-S24990024732012081600000)
2. see «CHECKING FUEL AND RESIDUAL PRESSURES»(ref-494826-S19525701392012081600000)
3. see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000) .

1. Continue Refer to «VERIFICATION»(ref-476747-S07620886872012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Test drive the vehicle on the road. Run a TRIP schedule so that the engine control module (ECM) compares the diagnostics. To run a TRIP schedule, see: «VERIFYING REPAIRS»(ref-494828-S19905032792012081600000)
4. Connect VCT2000 (or appropriate scan tool) to the data link connector (DLC) without switching off the engine. NOTE: If the engine is switched off, the stored fault status will be erased and the test drive will have to be repeated. Read off the diagnostic status and fault status for the diagnostic trouble code (DTC) by selecting the relevant diagnostic trouble code (DTC) from the list. Check the fault status for the diagnostic trouble code (DTC) when the diagnostic is "Complete". If the function is correct, the fault status must be "No fault found" when the diagnostic is complete.

Is the function OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S15209515722012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Check the intake system for air leakage.

HINT: Air leakage in the intake system can occur through the evaporative emission system (EVAP) valve, the secondary air solenoid valve or the power brake booster.

Check the exhaust system for leakage.

Check the fuel pressure and residual pressure.

Check that the oil level is within the minimum and maximum markings.

Check the viscosity of the engine oil by reading off the short-term fuel trim with the engine running. Plug the crankcase ventilation and read off the short-term fuel trim again. The value must be more or less unchanged.

Remedy as necessary.

Other information

1. see «CHECK FOR AIR LEAKS IN THE INTAKE SYSTEM»(ref-494823-S24990024732012081600000)
2. see «CHECKING FOR AIR LEAKAGE IN THE EXHAUST SYSTEM»(ref-494824-S07275287112012081600000)
3. see «CHECKING FUEL AND RESIDUAL PRESSURES»(ref-494826-S19525701392012081600000)

Was a fault detected?

1. YES Refer to «VERIFICATION»(ref-476747-S28238335562012060500000)
2. NO Refer to «CHECKING THE MASS AIR FLOW (MAF) SENSOR»(ref-476747-S33493793322012060500000)

Test drive the car for approximately 10 minutes.

Read off the correction factor of the mass air flow (MAF) sensor. The value must be between 0.8 and 1.2.

Note. There must not be any air leakage when this test is carried out.

Remedy as necessary.

Other information

1. see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000) .

1. Continue Refer to «VERIFICATION»(ref-476747-S28238335562012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Test drive the vehicle on the road. Run a TRIP schedule so that the engine control module (ECM) compares the diagnostics. To run a TRIP schedule, see: «VERIFYING REPAIRS»(ref-494828-S19905032792012081600000)
4. Connect VCT2000 (or appropriate scan tool) to the data link connector (DLC) without switching off the engine. NOTE: If the engine is switched off, the stored fault status will be erased and the test drive will have to be repeated. Read off the diagnostic status and fault status for the diagnostic trouble code (DTC) by selecting the relevant diagnostic trouble code (DTC) from the list. Check the fault status for the diagnostic trouble code (DTC) when the diagnostic is "Complete". If the function is correct, the fault status must be "No fault found" when the diagnostic is complete.

Is the function OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S26381168872012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

Check the intake system for air leakage.

HINT: Air leakage in the intake system can occur through the evaporative emission system (EVAP) valve, the secondary air solenoid valve or the power brake booster.

Check the fuel pressure.

Test drive the car for approximately 10 minutes.

Read off the correction factor of the mass air flow (MAF) sensor. The value must be between 0.8 and 1.2.

Note. There must not be any air leakage when this test is carried out.

Remedy as necessary.

Other information

1. see «CHECK FOR AIR LEAKS IN THE INTAKE SYSTEM»(ref-494823-S24990024732012081600000)
2. see «CHECKING FUEL AND RESIDUAL PRESSURES»(ref-494826-S19525701392012081600000)
3. see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000)

1. Continue Refer to «VERIFICATION»(ref-476747-S21687599232012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Test drive the vehicle on the road. Run a TRIP schedule so that the engine control module (ECM) compares the diagnostics. To run a TRIP schedule, see: «VERIFYING REPAIRS»(ref-494828-S19905032792012081600000)
4. Connect VCT2000 (or appropriate scan tool) to the data link connector (DLC) without switching off the engine. NOTE: If the engine is switched off, the stored fault status will be erased and the test drive will have to be repeated. Read off the diagnostic status and fault status for the diagnostic trouble code (DTC) by selecting the relevant diagnostic trouble code (DTC) from the list. Check the fault status for the diagnostic trouble code (DTC) when the diagnostic is "Complete". If the function is correct, the fault status must be "No fault found" when the diagnostic is complete.

Is the function OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S24611176442012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

see SIGNAL TOO HIGH

Check the intake system for air leakage.

HINT: Air leakage in the intake system can occur through the evaporative emission system (EVAP) valve, the secondary air solenoid valve or the power brake booster.

Check the exhaust system for leakage.

Check the fuel pressure and residual pressure.

Check that the oil level is within the minimum and maximum markings.

Check the viscosity of the engine oil by reading off the short-term fuel trim with the engine running. Plug the crankcase ventilation and read off the short-term fuel trim again. The value must be more or less unchanged.

Remedy as necessary.

Other information

1. see «CHECK FOR AIR LEAKS IN THE INTAKE SYSTEM»(ref-494823-S24990024732012081600000)
2. see «CHECKING FOR AIR LEAKAGE IN THE EXHAUST SYSTEM»(ref-494824-S07275287112012081600000)
3. see «CHECKING FUEL AND RESIDUAL PRESSURES»(ref-494826-S19525701392012081600000)

Was a fault detected?

1. YES Refer to «VERIFICATION»(ref-476747-S32228914592012060500000)
2. NO Refer to «CHECKING THE MASS AIR FLOW (MAF) SENSOR»(ref-476747-S07039331692012060500000)

Test drive the car for approximately 10 minutes.

Read off the correction factor of the mass air flow (MAF) sensor. The value must be between 0.8 and 1.2.

Note. There must not be any air leakage when this test is carried out.

Remedy as necessary.

Other information

1. see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000) .

1. Continue Refer to «VERIFICATION»(ref-476747-S32228914592012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Test drive the vehicle on the road. Run a TRIP schedule so that the engine control module (ECM) compares the diagnostics. To run a TRIP schedule, see: «VERIFYING REPAIRS»(ref-494828-S19905032792012081600000)
4. Connect VCT2000 (or appropriate scan tool) to the data link connector (DLC) without switching off the engine. NOTE: If the engine is switched off, the stored fault status will be erased and the test drive will have to be repeated. Read off the diagnostic status and fault status for the diagnostic trouble code (DTC) by selecting the relevant diagnostic trouble code (DTC) from the list. Check the fault status for the diagnostic trouble code (DTC) when the diagnostic is "Complete". If the function is correct, the fault status must be "No fault found" when the diagnostic is complete.

Is the function OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S15018952342012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

see SIGNAL TOO LOW

see SIGNAL TOO HIGH

see SIGNAL TOO LOW

This diagnostic trouble code can only be stored during lambda regulation quick tests. The test is normally run as verification after faults have been rectified. If the diagnostic trouble code is stored during the test, this means that faults remain to be remedied that can cause problems with lambda regulation. Continue with/return to manual navigation for fault tracing under the diagnostic trouble code related to lambda regulation.

see FAULT-TRACING INFORMATION

see FAULT-TRACING INFORMATION

Check the intake system for air leakage.

HINT: Air leakage in the intake system can occur through the evaporative emission system (EVAP) valve, the secondary air solenoid valve or the power brake booster.

Start the engine. Allow the engine to run at idle speed for 10 minutes.

Check the mass air flow (MAF) sensor. Read off its correction factor. The value must be between 2 and 12.

Note. There must not be any air leakage when this test is carried out.

Remedy as necessary.

Other information

1. see «CHECK FOR AIR LEAKS IN THE INTAKE SYSTEM»(ref-494823-S24990024732012081600000)
2. see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000) .

1. Continue Refer to «VERIFICATION»(ref-476747-S11904551532012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Test drive the vehicle on the road. Run a TRIP schedule so that the engine control module (ECM) compares the diagnostics. To run a TRIP schedule, see: «VERIFYING REPAIRS»(ref-494828-S19905032792012081600000)
4. Connect VCT2000 (or appropriate scan tool) to the data link connector (DLC) without switching off the engine. NOTE: If the engine is switched off, the stored fault status will be erased and the test drive will have to be repeated. Read off the diagnostic status and fault status for the diagnostic trouble code (DTC) by selecting the relevant diagnostic trouble code (DTC) from the list. Check the fault status for the diagnostic trouble code (DTC) when the diagnostic is "Complete". If the function is correct, the fault status must be "No fault found" when the diagnostic is complete.

Is the function OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S04957775742012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

see SIGNAL TOO HIGH

Check the intake system for air leakage.

HINT: Air leakage in the intake system can occur through the evaporative emission system (EVAP) valve, the secondary air solenoid valve or the power brake booster.

Check the exhaust system for leakage.

Check the fuel pressure and residual pressure.

Check that the oil level is within the minimum and maximum markings.

Check the viscosity of the engine oil by reading off the short-term fuel trim with the engine running. Plug the crankcase ventilation and read off the short-term fuel trim again. The value must be more or less unchanged.

Remedy as necessary.

Other information

1. see «CHECK FOR AIR LEAKS IN THE INTAKE SYSTEM»(ref-494823-S24990024732012081600000)
2. see «CHECKING FOR AIR LEAKAGE IN THE EXHAUST SYSTEM»(ref-494824-S07275287112012081600000)
3. see «CHECKING FUEL AND RESIDUAL PRESSURES»(ref-494826-S19525701392012081600000)

1. Continue Refer to «CHECKING THE MASS AIR FLOW (MAF) SENSOR»(ref-476747-S24490984052012060500000)

Read off the correction factor of the mass air flow (MAF) sensor. The value must be between 2 and 12.

Note. There must not be any air leakage when this test is carried out.

Remedy as necessary.

Other information

1. see «MASS AIR FLOW (MAF) SENSOR, REPLACING»(ref-476751-S11580805602012060500000) .

1. Continue Refer to «VERIFICATION»(ref-476747-S20627724172012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Test drive the vehicle on the road. Run a TRIP schedule so that the engine control module (ECM) compares the diagnostics. To run a TRIP schedule, see: «VERIFYING REPAIRS»(ref-494828-S19905032792012081600000)
4. Connect VCT2000 (or appropriate scan tool) to the data link connector (DLC) without switching off the engine. NOTE: If the engine is switched off, the stored fault status will be erased and the test drive will have to be repeated. Read off the diagnostic status and fault status for the diagnostic trouble code (DTC) by selecting the relevant diagnostic trouble code (DTC) from the list. Check the fault status for the diagnostic trouble code (DTC) when the diagnostic is "Complete". If the function is correct, the fault status must be "No fault found" when the diagnostic is complete.

Is the function OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S12007858762012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

see SIGNAL TOO LOW

see SIGNAL TOO HIGH

see SIGNAL TOO HIGH

see SIGNAL TOO LOW

see FAULT-TRACING INFORMATION

see FAULT-TRACING INFORMATION

see FAULT-TRACING INFORMATION

see FAULT-TRACING INFORMATION

Check power cable terminal #1 in the rear heated oxygen sensor (HO2S) connector. Check for contact resistance. Check for oxidation.

Check ground lead terminal #2 in the rear heated oxygen sensor (HO2S) connector. Check for contact resistance. Check for oxidation.

Try a new heated oxygen sensor (HO2S) if the above fault-tracing does not remedy the fault.

Remedy as necessary.

Other information

1. see «HEATED OXYGEN SENSOR (HO2S), REPLACING»(ref-476768-S23777230272012060500000)
2. see «CHECKING WIRING AND TERMINALS»(ref-476689-S17283010372012060500000)

1. Continue Refer to «VERIFICATION»(ref-476747-S31917916102012060500000)

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Start the engine. Read off the diagnostic status and fault status for the diagnostic trouble code (DTC) by selecting the relevant diagnostic trouble code (DTC) from the list. Increase the engine speed to 2500 RPM until the diagnostic is "Complete". Check the fault status for the diagnostic trouble code (DTC) when the diagnostic is "Complete". If the function is correct, the fault status must be "No fault found" when the diagnostic is complete.

Is the function OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S18051889972012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

see FAULTY SIGNAL

HINT: After carrying out the repair, check that the fault has been remedied.

1. Ignition off
2. Reconnect the connectors, reinstall components etc.
3. Start the engine. Allow the engine to idle for at least 1 minute
4. Test drive the car at an even speed (approximately 80 km/h for at least 5 minutes)
5. Connect VCT2000 (or appropriate scan tool) to the data link connector (DLC) without switching off the engine. NOTE: If the engine is switched off, the stored fault status will be erased and the test drive will have to be repeated. Read off the diagnostic status and fault status for the diagnostic trouble code (DTC) by selecting the relevant diagnostic trouble code (DTC) from the list. Check the fault status for the diagnostic trouble code (DTC) when the diagnostic is "Complete". If the function is correct, the fault status must be "No fault found" when the diagnostic is complete.

Is the function OK?

1. YES VERIFIED: Troubleshooting has been completed.
2. NO Refer to «INFORMATION»(ref-476747-S14322772872012060500000)

The fault should have been detected and remedied. As this is not the case fault-tracing has failed.

Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.

SIGNAL TOO HIGH/SIGNAL TOO LOW/SIGNAL MISSING

see SIGNAL TOO HIGH/SIGNAL TOO LOW/SIGNAL MISSING