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Code P0172 Topic is solved

Help, Advice, Owners' Discussion and DIY Tutorials devoted to the second generation C70, S40 and V50 Volvos -- awkwardly model year 2004 ½ onwards -- plus where to go for advice and discussion on Volvo's sporty C30 Coupe powered by Volvo's ubiquitous inline 5-cylinder power plant.
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Cukhe2000
Posts: 2
Joined: 20 Jun 2022, 16:20
Year and Model: 2008 S-40i
Location: Virginia

Code P0172

Post by Cukhe2000 »

Hi,
First time I ran to problems to troubleshoot my 2008 S-40i, manual transmission, 235 k, one owner. I got the code P172, replaced both O2 ,MAF, and Fuel pressure sensors, tested my vacuum brake motor apply12v heard the pump sound… opened oil cap have good vacuum. Replaced my oil breather unit and hoses 70k ago. Great appreciate for any advice…

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RickHaleParker
Posts: 6993
Joined: 25 May 2015, 14:30
Year and Model: See Signature below.
Location: Kansas
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Post by RickHaleParker »

ECM-250A (P0172) Long-term fuel trim. B5244S4


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.
    Too high ethanol content in fuel.
    Air leakage in the intake system.
    Air leakage in the exhaust system.
    Low fuel pressure.
    Damaged mass air flow (MAF) sensor.
    Damaged, dirty oil trap.
    Clogged air filter.
    Dirty mass air flow 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.
    Damaged, dirty oil trap.
    Clogged air filter.
    Dirty mass air flow sensor.
⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙⸙
1998 C70, B5234T3, 16T, AW50-42, Bosch Motronic 4.4, Special Edition package.
2003 S40, B4204T3, 14T twin scroll AW55-50/51SN, Siemens EMS 2000.
2004 S60R, B8444S TF80 AWD. Yamaha V8 conversion
2005 XC90 T6 Executive, B6294T, 4T65 AWD, Bosch Motronic 7.0.

Cukhe2000
Posts: 2
Joined: 20 Jun 2022, 16:20
Year and Model: 2008 S-40i
Location: Virginia

Post by Cukhe2000 »

Thank you, next steps to replace oil trap and hoses to see. Engine/RPM/gas miles are normal.

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