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Enes, VOLVO Master Technician
Category: Volvo
Satisfied Customers: 4905
Experience:  15+YEARS WITH VOLVO AS THE MASTER VOLVO MECHANIC&Ase
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P0172 2006 volvo S40, cleaned MAF sensor, new upstream O2

Customer Question

P0172 2006 volvo S40, cleaned MAF sensor, new upstream O2 sensor, new oil filter housing (recall) PCV-to-manifold rubber hose, new plugs
Submitted: 4 months ago.
Category: Volvo
Customer: replied 4 months ago.
Check engine light on. When P0172 code is cleared with OBDII software (or battery disconnection), it returns after some driving time.
Expert:  Chad Farhat replied 4 months ago.

Hi, I'm Chad. Welcome to JustAnswer. I'm reviewing your question and I will be posting your reply ASAP.

Customer: replied 4 months ago.
I had meant to say that the large-diameter rubber hose from the oil filter housing to the intake manifold (PCV system engine vacuum) is also "new"
Expert:  Chad Farhat replied 4 months ago.

Hey how are you

1- P0172 = ECM 250A for Volvo

2006 Volvo S40 L5-2.4L VIN 38 B5244S4

Save Article

Diagnostic trouble code (DTC) information ECM-250A Condition Engine Control Module (ECM) receives information from the heated oxygen sensor about fuel/air mixture in different load areas. If Engine Control Module (ECM) registers that fuel/air mixture deviates too much from target lambda, so that adaptations end up in any of its end-positions, the diagnostic trouble code is generated. Substitute value - None. Possible source Upper limit - Incorrectly installed oil dipstick. Air leakage. - Air leakage in the intake system. - Air leakage in the exhaust system. - Low fuel pressure. - Damaged mass air flow (MAF) sensor. Lower limit - Oil level too high. - Contaminated engine oil. - Leaking injectors. - Damaged evaporative emission system (EVAP) valve. - High fuel pressure. - Damaged mass air flow (MAF) sensor. Fault symptom[s] - Warning lights and chimes/Malfunction Indicator Light ("Check engine" light) indication/no indication - Text window and warning symbol/Yellow symbol and text message - Driving/Poor performance/lacks power - Fuel system/Excessive fuel consumption

© 2017 ALLDATA, LLC. All Rights Reserved. Terms of Use (Version 2.0.13830)

Expert:  Chad Farhat replied 4 months ago.

Lower limit Preparatory checks Check and note which adaptation range is incorrect. Scroll through the list of adaptation ranges. The adaptation value is considered outside normal range if it is lower than 0.85 (engine runs rich) or higher than 1.15 (engine runs lean). Hint: The ranges consist of a table where the first digit in the name designates the engine speed range and the second the loading range. Range 1.1 designates a case with low engine speed and with low loading. Range 6.6 designates a case with high engine speed and with high loading.

Zoom and Print Options

Continue - Checking the system

-------------------------------------------------

Checking the mass air flow (MAF) sensor

Zoom and Print Options

Zoom and Print Options

- Engine running.
Check and compare the calculated air mass with the actual, read-out from mass air flow sensor. Try measuring at different speeds (rpm).

Hint: Differences of more than 20 % between the signals indicate a defective mass air flow sensor.

Remedy as necessary.

Note! When replacing mass air flow sensor. Repeat the check to verify that the replacement solved the problem.

1. For more information about current fuel compensation.
2. Select Continue.

Zoom and Print Options

Select one of the above options.

1 - Read-out of total fuel compensation

2 - Resetting adaptation

-------------------------------------------------

Read-out of total fuel compensation

Zoom and Print Options

- Engine running.
- For read-out of total fuel compensation at every given moment, press the symbol for VCT2000.

Hint: The read-out value shows the short term fuel trims's and the long term fuel trim's total compensation of injection time in real-time. Positive values indicate addition of fuel. Negative values indicate reduction of fuel.

Try measuring at different speeds (rpm) with different engine loading.

Note! Keep in mind that the EVAP-valve's addition of fuel vapors affects the read-out. Squeeze the hose between the EVAP-valve and inlet pipe to minimize the addition of fuel from the EVAP-system.

Zoom and Print Options

Continue - Resetting adaptation

-------------------------------------------------

Resetting adaptation

Zoom and Print Options

- Switch off the engine.
- Ignition on.
Reset the adaptations by pressing the VCT2000 symbol.
This is done so that the system can be started from normal. As a result, it is easier to see if the adaptations are going up or down.

Zoom and Print Options

Continue - Start adaptations

-------------------------------------------------

Start adaptations

Zoom and Print Options

Test-drive the vehicle on road and drive a little in different operating situations for 20 minutes, in order to complete as many adaptations as possible.
Check and note if any adaptation range is still incorrect. Scroll through the list of adaptation ranges.
The adaptation value is considered outside normal range if it is lower than 0.85 (engine runs rich) or higher than 1.15 (engine runs lean).

Hint: Also accelerate at full throttle a number of times to implement the adaptations that are not influenced by normal driving.

For adaptation to start, certain conditions must be fulfilled
- The engine speed is above 600 rpm.
- Engine temperature between 80-110°C.
- Fuel trim active = executed.
- EVAP-valve not active = 0 micros.

Hint: If fuel vaporization is high, the evaporative emission system (EVAP) valve is active for long periods. In this case, it may be necessary to disconnect the hose between the evaporative emission system (EVAP) valve and the EVAP canister.

Zoom and Print Options

Are these values OK?

Yes - Fault Found

No - Fault-tracing information

-------------------------------------------------

Fault-tracing information

Information

Fault-tracing information
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.

Do you want to exit fault-tracing?

Yes - Exit Fault-Tracing

No - Attempt New Test

------------------------

Attempt New Test - Preparatory checks

-------------------------------------------------

Checking the system

Zoom and Print Options

Hint: If fuel adaptations indicate too rich fuel/air mixture (adaptation value below 1.0) in several adaptation ranges, this indicates a fuel malfunction. The cause may be too high fuel pressure.

To investigate what the problem is due to, perform the following:
- Check that the oil level is between the minimum and maximum markings

Hint: Adaptations may show rich fuel/air mixture if several short drives have taken place and the engine oil thus has been contaminated by gasoline.

- Check the EVAP-valve for leakage.

Hint: A leaking valve gives a constant contribution of fuel vapors that affect the adaptations.

- Engine running.
- Check the fuel pressure for high fuel pressure.
- Ignition on.
- Check the residual pressure with regards ***** ***** low residual pressure.
Remedy as necessary.

Hint: If the residual pressure is too low, leaking injection valves may be the cause.

Other information
- Fuel system pressure, checking See: Fuel Delivery and Air Induction > Component Tests and General Diagnostics > Fuel System Pressure, Checking

Zoom and Print Options

Continue - Checking the mass air flow (MAF) sensor

-------------------------------------------------

© 2017 ALLDATA, LLC. All Rights Reserved. Terms of Use (Version 2.0.13830)

Lower limit Preparatory checks Check and note which adaptation range is incorrect. Scroll through the list of adaptation ranges. The adaptation value is considered outside normal range if it is lower than 0.85 (engine runs rich) or higher than 1.15 (engine runs lean). Hint: The ranges consist of a table where the first digit in the name designates the engine speed range and the second the loading range. Range 1.1 designates a case with low engine speed and with low loading. Range 6.6 designates a case with high engine speed and with high loading.

Zoom and Print Options

Continue - Checking the system

-------------------------------------------------

Checking the mass air flow (MAF) sensor

Zoom and Print Options

Zoom and Print Options

- Engine running.
Check and compare the calculated air mass with the actual, read-out from mass air flow sensor. Try measuring at different speeds (rpm).

Hint: Differences of more than 20 % between the signals indicate a defective mass air flow sensor.

Remedy as necessary.

Note! When replacing mass air flow sensor. Repeat the check to verify that the replacement solved the problem.

1. For more information about current fuel compensation.
2. Select Continue.

Zoom and Print Options

Select one of the above options.

1 - Read-out of total fuel compensation

2 - Resetting adaptation

-------------------------------------------------

Read-out of total fuel compensation

Zoom and Print Options

- Engine running.
- For read-out of total fuel compensation at every given moment, press the symbol for VCT2000.

Hint: The read-out value shows the short term fuel trims's and the long term fuel trim's total compensation of injection time in real-time. Positive values indicate addition of fuel. Negative values indicate reduction of fuel.

Try measuring at different speeds (rpm) with different engine loading.

Note! Keep in mind that the EVAP-valve's addition of fuel vapors affects the read-out. Squeeze the hose between the EVAP-valve and inlet pipe to minimize the addition of fuel from the EVAP-system.

Zoom and Print Options

Continue - Resetting adaptation

-------------------------------------------------

Resetting adaptation

Zoom and Print Options

- Switch off the engine.
- Ignition on.
Reset the adaptations by pressing the VCT2000 symbol.
This is done so that the system can be started from normal. As a result, it is easier to see if the adaptations are going up or down.

Zoom and Print Options

Continue - Start adaptations

-------------------------------------------------

Start adaptations

Zoom and Print Options

Test-drive the vehicle on road and drive a little in different operating situations for 20 minutes, in order to complete as many adaptations as possible.
Check and note if any adaptation range is still incorrect. Scroll through the list of adaptation ranges.
The adaptation value is considered outside normal range if it is lower than 0.85 (engine runs rich) or higher than 1.15 (engine runs lean).

Hint: Also accelerate at full throttle a number of times to implement the adaptations that are not influenced by normal driving.

For adaptation to start, certain conditions must be fulfilled
- The engine speed is above 600 rpm.
- Engine temperature between 80-110°C.
- Fuel trim active = executed.
- EVAP-valve not active = 0 micros.

Hint: If fuel vaporization is high, the evaporative emission system (EVAP) valve is active for long periods. In this case, it may be necessary to disconnect the hose between the evaporative emission system (EVAP) valve and the EVAP canister.

Zoom and Print Options

Are these values OK?

Yes - Fault Found

No - Fault-tracing information

-------------------------------------------------

Fault-tracing information

Information

Fault-tracing information
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.

Do you want to exit fault-tracing?

Yes - Exit Fault-Tracing

No - Attempt New Test

------------------------

Attempt New Test - Preparatory checks

-------------------------------------------------

Checking the system

Zoom and Print Options

Hint: If fuel adaptations indicate too rich fuel/air mixture (adaptation value below 1.0) in several adaptation ranges, this indicates a fuel malfunction. The cause may be too high fuel pressure.

To investigate what the problem is due to, perform the following:
- Check that the oil level is between the minimum and maximum markings

Hint: Adaptations may show rich fuel/air mixture if several short drives have taken place and the engine oil thus has been contaminated by gasoline.

- Check the EVAP-valve for leakage.

Hint: A leaking valve gives a constant contribution of fuel vapors that affect the adaptations.

- Engine running.
- Check the fuel pressure for high fuel pressure.
- Ignition on.
- Check the residual pressure with regards ***** ***** low residual pressure.
Remedy as necessary.

Hint: If the residual pressure is too low, leaking injection valves may be the cause.

Other information
- Fuel system pressure, checking See: Fuel Delivery and Air Induction > Component Tests and General Diagnostics > Fuel System Pressure, Checking

Zoom and Print Options

Continue - Checking the mass air flow (MAF) sensor

-------------------------------------------------

© 2017 ALLDATA, LLC. All Rights Reserved. Terms of Use (Version 2.0.13830)

Expert:  Chad Farhat replied 4 months ago.

Upper limit Preparatory checks Check and note which adaptation range is incorrect. Scroll through the list of adaptation ranges. The adaptation value is considered outside normal range if it is lower than 0.85 (engine runs rich) or higher than 1.15 (engine runs lean). Hint: The ranges consist of a table where the first digit in the name designates the engine speed range and the second the loading range. Range 1.1 designates a case with low engine speed and with low loading. Range 6.6 designates a case with high engine speed and with high loading.

Zoom and Print Options

Continue - Checking the system

-------------------------------------------------

Checking the mass air flow (MAF) sensor

Zoom and Print Options

Zoom and Print Options

- Engine running.
Check and compare the calculated air mass with the actual, read-out from mass air flow sensor. Try measuring at different speeds (rpm).

Hint: Differences of more than 20 % between the signals indicate a defective mass air flow sensor.

Remedy as necessary.

Note! When replacing mass air flow sensor. Repeat the check to verify that the replacement solved the problem.

1. For more information about current fuel compensation.
2. Select Continue.

Zoom and Print Options

Select one of the above options.

1 - Read-out of total fuel compensation

2 - Resetting adaptation

-------------------------------------------------

Read-out of total fuel compensation

Zoom and Print Options

- Engine running.
- For read-out of total fuel compensation at every given moment, press the symbol for VCT2000.

Hint: The read-out value shows the short term fuel trims's and the long term fuel trim's total compensation of injection time in real-time. Positive values indicate addition of fuel. Negative values indicate reduction of fuel.

Try measuring at different speeds (rpm) with different engine loading.

Note! Keep in mind that the EVAP-valve's addition of fuel vapors affects the read-out. Squeeze the hose between the EVAP-valve and inlet pipe to minimize the addition of fuel from the EVAP-system.

Zoom and Print Options

Continue - Resetting adaptation

-------------------------------------------------

Resetting adaptation

Zoom and Print Options

- Switch off the engine.
- Ignition on.
Reset the adaptations by pressing the VCT2000 symbol.
This is done so that the system can be started from normal. As a result, it is easier to see if the adaptations are going up or down.

Zoom and Print Options

Continue - Start adaptations

-------------------------------------------------

Start adaptations

Zoom and Print Options

Test-drive the vehicle on road and drive a little in different operating situations for 20 minutes, in order to complete as many adaptations as possible.
Check and note if any adaptation range is still incorrect. Scroll through the list of adaptation ranges.
The adaptation value is considered outside normal range if it is lower than 0.85 (engine runs rich) or higher than 1.15 (engine runs lean).

Hint: Also accelerate at full throttle a number of times to implement the adaptations that are not influenced by normal driving.

For adaptation to start, certain conditions must be fulfilled
- The engine speed is above 600 rpm.
- Engine temperature between 80-110°C.
- Fuel trim active = executed.
- EVAP-valve not active = 0 micros.

Hint: If fuel vaporization is high, the evaporative emission system (EVAP) valve is active for long periods. In this case, it may be necessary to disconnect the hose between the evaporative emission system (EVAP) valve and the EVAP canister.

Zoom and Print Options

Are these values OK?

Yes - Fault Found

No - Fault-tracing information

-------------------------------------------------

Fault-tracing information

Information

Fault-tracing information
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.

Do you want to exit fault-tracing?

Yes - Exit Fault-Tracing

No - Attempt New Test

------------------------

Attempt New Test - Preparatory checks

-------------------------------------------------

Checking the system

Zoom and Print Options

To investigate what the problem is due to, perform the following:
- Check the intake system for air leakage.

Hint: Incorrectly installed oil dipstick can cause not measured air to be drawn into the engine.

- Check the exhaust system for air leakage.
- Engine running.
- Check for too low fuel pressure.
- Ignition on.
- Check the residual pressure with regards ***** ***** low residual pressure.
Remedy as necessary.
- Air leaks in the intake system, checking See: A L L Diagnostic Trouble Codes ( DTC ) > Related Tests, Information and Procedures > Air Leaks in the Intake System, Checking
- Air leakage exhaust system, check See: A L L Diagnostic Trouble Codes ( DTC ) > Related Tests, Information and Procedures > Air Leakage Exhaust System, Check
- Fuel system pressure, checking See: Fuel Delivery and Air Induction > Component Tests and General Diagnostics > Fuel System Pressure, Checking

Zoom and Print Options

Continue - Checking the mass air flow (MAF) sensor

-------------------------------------------------

© 2017 ALLDATA, LLC. All Rights Reserved. Terms of Use (Version 2.0.13830)

Expert:  Chad Farhat replied 4 months ago.

Please check here

Possible source Upper limit - Incorrectly installed oil dipstick. Air leakage. - Air leakage in the intake system. - Air leakage in the exhaust system. - Low fuel pressure. - Damaged mass air flow (MAF) sensor. Lower limit - Oil level too high. - Contaminated engine oil. - Leaking injectors. - Damaged evaporative emission system (EVAP) valve. - High fuel pressure. - Damaged mass air flow (MAF) sensor. Fault symptom[s] - Warning lights and chimes/Malfunction Indicator Light ("Check engine" light) indication/no indication - Text window and warning symbol/Yellow symbol and text message - Driving/Poor performance/lacks power - Fuel system/Excessive fuel consumption