b"Navigating the Mazestampedstamped record record of all of the allfaultsthe faults present present on a on vehicle a vehiclehighhigh on the onlisttheoflist suspects. of suspects. However, However, a mechanical a mechanical beforebefore it was it evenwas even pulled pulled intointoa service a service bay.bay.This This cancanfailurefailure of ablendof a blend door door could could notbenot completely be completely ruled ruled DOVR\x03DOVR\x03EH\x03D\x03EH\x03 UVW\x03 GHIHQVH\x03 WKH\x03 WKH\x03GUHDGHG\x03\x05HYHU\x03\x05HYHU\x03 out just yet. most plausible explanation based based UVW\x03D\x03 OLQH\x03OLQH\x03RI\x03 RI\x03GHIHQVH\x03WR\x03 WR\x03GUHDGHG\x03 outjustyet.TheThemost plausibleexplanation of a Volkswagen GTIan AutomotiveTechInfo.com publication VLQFH\x05\x03V\\QGURPH\x11\x03 on theGTIwasunremarkable.on availableVLQFH\x05\x03V\\QGURPH\x11\x03 on available information information was wasa blockage, a blockage, restriction, restriction, RU\x03RWKHU\x03W\\SH\x03RI\x03FRRODQW\x03RZ\x03LVVXH\x11\x03The Thepre-scanpre-scanonthe GTIwasunremarkable. RU\x03RWKHU\x03W\\SH\x03RI\x03FRRODQW\x03RZ\x03LVVXH\x11\x03With No Heat ThereThere were were a couple a couple of low of voltagelow voltage codes, codes, a heated a heated passenger seatseatfault, fault, code satellite passenger andandoneonecode fortheforsatellitethe radioradiotunertuner storedinInformation Electronicsstoredinthe theInformationElectronics ModuleModule(this(this faultispresentanytime satellite faultispresentanytimethe thesatelliteradio subscription has lapsed). radio subscription has lapsed). WR\x03HYDOXDWH\x03WKH\x03 WKH\x03SUHYLRXV\x03UHSDLUV\x03UHSDLUV\x037KH\x037KH\x03UVW\x03UVW\x03VWHS\x03VWHS\x03ZDV\x03ZDV\x03WR\x03HYDOXDWH\x03 SUHYLRXV\x03and andthecurrentstatestatethe coolingsystem.TheThe thecurrent ofofthecoolingsystem.heaterheatercoreinstallation lookedgood.No No leaks coreinstallationlookedgood. leaks appearedappeared under under the dash the dash and alland panels all panels were were in their in their place.place.TheThecoolantcoolant level fullinexpansionFew things will get a vehicle in for service like a passengerlevelwaswasfullinthe theexpansion tank,tank, but it but was it stillwas possiblestill possible there there was airwas trapped air trapped in in FRPSDUWPHQW\x03WKDW\x03GRHVQW\x03KHDW\x03XS\x03LQ\x03WKH\x03ZLQWHU\x03\x0bRU\x03FRRO\x03R\x03LQ\x03 the system from the prior service. the system from the prior service. summer). Of course, if a vehicle wont start it has to be towed to the shop, but customers will often ignore a warning lightWhileWhile on the ontopicthe topic of the ofexpansionthe expansion tank tank there there is a is a or unusual noise for as long as they can. This was the case onVLGH\x03VLGH\x03QRWH\x03QRWH\x03ZRUWK\x03ZRUWK\x03PHQWLRQLQJ\x1d\x03PHQWLRQLQJ\x1d\x03VRPH\x03VRPH\x039$*\x039$*\x03YHKLFOHV\x03YHKLFOHV\x03KDYH\x03KDYH\x03our 2015 Golf GTI subject vehicle. The service message wasa silicaa silica bag locatedbag located inside inside thetank.the tank. The Thebag isbag there is there long overdue, and the telltale squeal from the rear wheelsto extendofcoolant andandtraptrapcorrosive to extend thelifetheoflife the the coolant corrosive contaminants.said that the brakes were also in need of attention. Neithercontaminants. This This is all is well allwelland goodand good until until the bag thebag UXSWXUHV\x03of those items was in the work order though, only a poorUXSWXUHV\x03DQG\x03VHQGV\x03DQG\x03VHQGV\x03QH\x03JUDLQV\x03QH\x03JUDLQV\x03RI\x03VLOLFDWH\x03RI\x03VLOLFDWH\x03WKURXJKRXW\x03WKURXJKRXW\x03the cooling system, wreaking havoc along the way. heating complaint was listed.the cooling system, wreaking havoc along the way. The Theheater heateris particularly susceptible to silica The owner of the GTI reported that it wasnt until halfway core core is particularly susceptible to silicathrough his nearly hour-long commute to work that there wasblockage, tosmall capillarypassages. blockage, duedueto the the small capillary passages. TheThe bag bagseemsseems mostsusceptibletoleburstingwhenwhen the QDOO\\\x03KHDW\x03IURP\x03WKH\x03YHQWV\x11\x03$OO\x03RWKHU\x03IXQFWLRQV\x0f\x03OLNH\x03WKH\x03EORZHU\x03 mostsusceptib tobursting the engineengineisoverheated, so ruptured silicasilica pouch speeds and mode selection, worked correctlyjust no heat.isoverheated,asoarupturedpouch shouldshould be viewed be viewed as aassecondary a secondary problem, problem, with with thethe $\x03 WKRURXJK\x03 FXVWRPHU\x03 LQWHUYLHZ\x03 XQFRYHUHG\x03 PRUH\x03 RI\x03 WKH\x03 VWRU\\\x11\x03 7KH\x03 primaryprimaryreasonforoverheating stillstilltotodeter- -reason foroverheatingbe bedeter ofbag is indicatedbyV\\PSWRPV\x03KDG\x03EHHQ\x03SUHVHQW\x03IRU\x03D\x03IHZ\x03ZHHNV\x03QRZ\x0f\x03DQG\x03D\x03GLHUHQW\x03UHSDLU\x03 mined.mined. TheThepresence presence of the the bag is indicated by the the shop had replaced the heater core a few days ago. The new heater coreZRUGV\x03ZRUGV\x03\x05PLW\x03\x05PLW\x036LOLNDW\x05\x036LOLNDW\x05\x03SULQWHGSULQWHG\x03RQ\x03WKH\x03\x03RQ\x03VLGH\x03WKH\x03VLGH\x03RI\x03WKH\x03RI\x03WDQN\x0f\x03WKH\x03WDQN\x0f\x03had not improved the situation at all, and now the owner did not haveZKLFK\x03LV\x03*HUPDQ\x03IRU\x03\x05ZLWK\x03VLOLFDWH\x11\x05ZKLFK\x03LV\x03*HUPDQ\x03IRU\x03\x05ZLWK\x03VLOLFDWH\x11\x05DQ\\\x03FRQGHQFH\x03OHIW\x03LQ\x03WKH\x03RULJLQDO\x03VKRS\x11\x03 7KLV\x037KLV\x03*7,\x03*7,\x03KDWFKEDFN\x03KDWFKEDFN\x03ZDV\x03ZDV\x03QRW\x03VXHULQJ\x03QRW\x03VXHULQJ\x03IURP\x03IURP\x03VLOLFDWH\x03VLOLFDWH\x03blockage though,so sothere besomeotherotherExpansion Tank with Silica$IWHU\x03 UHDVVXULQJ\x03 WKH\x03 RZQHU\x03 WKDW\x03 WKH\x03 SUREOHP\x03 ZRXOG\x03 EH\x03 FRUUHFWO\\\x03 blockagethough,therehadhadtotobesome Expansion Tank with Silicareasonreasonfortheforlack heat.Beginning withwithafull diagnosed,andonlynecessarypartswouldbeinstalled,thevehiclethelackofofheat.Beginningafullcheck-in process was completed and the hatchback was dispatched to thesystemsystem perspe perspectivective and reviewingand reviewing the data the data known known so soG32 Engine far would provide a clear path for the diagnosis.CoverCover G32 Engine shops European specialist. Part of the check-in process was a pre-scanfar would provide a clear path for the diagnosis.Coolant Level Coolant Level ofallmodulespresentThe Theheaterheater waswas new, buthad had made noCoolantSensorSensorcorecore new,but ititmadeno Coolant onthevehicle.Thisisimprovement tothe the ofcabinheat.heat.ThereExpansionCoolant improvementto lacklack ofcabin ThereExpansionCoolant apracticethatshopswerewere nono fault codes present related toengine,TankTank ReturnReturnshouldthinkaboutfault codes present related to the the engine,FRROLQJ\x03FRROLQJ\x03V\\VWHPV\\VWHP\x0f\x03RU\x03\x0f\x03+9$&\x03FRPSRQHQWV\x11\x03RU\x03+9$&\x03FRPSRQHQWV\x11\x037KHUH\x037KHUH\x03ZHUH\x03ZHUH\x03adopting if they are notnooverheatingthethesystemSilicate Silicate nooverheating concerns, concerns, sosocooling coolingsystem DOUHDG\\\x11\x03$\x03SUH\x10VFDQ\x03GRQH\x03 Containerappeared tobeworkingcorrectly apartapart from theContainerappearedtobeworkingcorrectlyfromthe intheparkinglotbyaheating concern. heating concern.SilicateSilicateVHUYLFH\x03 ZULWHU\x03 RU\x03 RFH\x03assistantishelpfultoThereThere was wasthepossibilitythe possibility thatthata blend a blend door door actuator actuatorCoolant ZDV\x03ZDV\x03QRW\x03DOORZLQJ\x03 EH\x03 EH\x03GLUHFWHG\x03DFURVV\x03DFURVV\x03WKH\x03 WKH\x03 Coolant the technician, but moreQRW\x03DOORZLQJ\x03DLURZ\x03DLURZ\x03WR\x03 WR\x03GLUHFWHG\x03 SupplySupplyheaterheatermatrix,butbutwithout fault codesinthe importantly, it providesmatrix, withoutanyanyfaultcodesintheOriginalinsurancefortheshopRU\x03 WHOOWDOH\x03FOLFNLQJ\x03FOLFNLQJ\x03VRXQGV\x03VRXQGV\x03IURP\x03IURP\x03 Expansion Tank - Cross View +9$&\x03+9$&\x03FRQWUROOHU\x03FRQWUROOHU\x03RU\x03 WHOOWDOH\x03 Expansion Tank - Cross View withinwithin the depths the depths of the of dashboard, the dashboard, that thatdid not did seem not seem(Image Courtesy Volkswagen)N82 Valve 2015 VW Golf GTI 2.0L Turbo to have a dated and time(Image Courtesy Volkswagen)29 8VolkswagencoolingsystemscanseemaThecoolingsystememploysavarietyofstrategies,buttwoofthose bit like a maze at times, with hoses teeingstrategiesweremostpertinenttothisdiagnosis:EngineWarmingand R\x03RI\x03HDFK\x03RWKHU\x03DQG\x03URXWLQJ\x03HYHU\\\x03ZKLFK\x03 IndependentHeating.EngineWarmingtakesplaceduringacoldstart. ZD\\\x03XQGHU\x03WKH\x03KRRG\x11\x037KH\x03RZ\x03GLDJUDP\x03LQ\x03 7KH\x03URWDU\\\x03VOLGH\x03YDOYHV\x03LQ\x03WKH\x03WHPSHUDWXUH\x03DFWXDWRU\x03UHVWULFW\x03FRRODQW\x03RZ\x0f\x03serviceinformationfurthercementstheallowing the engine to reach closed loop operating temperatures as quickly feeling of being lost in a maze full of twistsaspossible.Thiscontributestoloweredemissionsandincreasedfuel and turns and dead ends.HFRQRP\\\x11\x037KH\x03FRRODQW\x03VKXW\x10R\x03YDOYHV\x03DUH\x03FORVHG\x03GXULQJ\x03WKH\x03ZDUPLQJ\x03SKDVH\x03DV\x03 ZHOO\x11\x03 $IWHU\x03 VXFLHQW\x03 KHDWLQJ\x03 RI\x03 WKH\x03 HQJLQH\x0f\x03 WKH\x03 WUDQVPLVVLRQ\x03 FRRODQW\x03ThismazeismadeevenmorecomplexVKXW\x10R\x03YDOYH\x03RSHQV\x0f\x03DQG\x03WKH\x03URWDU\\\x03VOLGHV\x03PRYH\x03WR\x03DOORZ\x03IXOO\x03RZ\x03WKURXJK\x03EHFDXVH\x03 WKH\x03 RZ\x03 FDQ\x03 PRUSK\x03 GHSHQGLQJ\x03 the radiator. onenginetemperatureandoperatingThe Independent Heating strategy kicks in when a heat setting is selected FRQGLWLRQV\x11\x03 6HUYLFH\x03 LQIRUPDWLRQ\x03 LV\x03 HDVLO\\\x03 E\\\x03 WKH\x03 GULYHU\x11\x03 ,Q\x03 WKLV\x03 VFHQDULR\x03 WKH\x03 1\x1b\x15\x03 FRRODQW\x03 VKXWR\x03 YDOYH\x03 ZLOO\x03 EH\x03forgotten,butisjustwhatwasneededinCooling SystemRSHQHG\x0f\x03DOORZLQJ\x03FRRODQW\x03RZ\x03WKURXJK\x03WKH\x03KHDWHU\x03FRUH\x03WR\x03PHHW\x03WKH\x03FDELQ\x03this case to gain a clear understanding of)ORZ\x03'LDJUDP heating demands. The electric coolant recirculation pump may also be the cooling system components and theorycommanded On. of operation. :LWK\x03 D\x03 FOHDU\x03 XQGHUVWDQGLQJ\x03 RI\x03 FRRODQW\x03 RZ\x03 DQG\x03 WKH\x03 GLHUHQW\x03 RSHUDWLQJ\x03TheheartofthethermalmanagementsystemistheN493enginemodes of the thermal management system, it was time to create an action temperaturecontrolactuator,whichutilizestworotaryslidevalvestoSODQ\x03VWDUWLQJ\x03ZLWK\x03WKH\x03OHDVW\x03LQYDVLYH\x03WHVWV\x03UVW\x11\x037\\SLFDOO\\\x0f\x03WKH\x03EHVW\x03WHVWV\x03WR\x03GLUHFW\x03FRRODQW\x03RZ\x03DQG\x03KRXVHV\x03WKH\x03WRRWKHG\x03EHOW\x10GULYHQ\x03FRRODQW\x03SXPS\x03DQG\x03 start with can be done with a scan tool from the front seat of the vehicle.thermostat wax capsule.$FWLRQ\x033ODQ\x033ULRULW\\\x03/LVW\x1dThere is also an electric after-run coolant pump, a recirculation pump, and5XQ\x03WKH\x03EOHQG\x03GRRU\x03FDOLEUDWLRQ\x03LQ\x03%DVLF\x036HWWLQJV\x03WR\x03YHULI\\\x03RSHUDWLRQ\x03WZR\x03FRRODQW\x03VKXWR\x03YDOYHV\x03LQ\x03WKH\x03V\\VWHP\x11\x032QH\x03RI\x03WKH\x03VKXWR\x03YDOYHV\x03LV\x03RQ\x03WKH\x03 DQG\x03FRQUP\x03QR\x03IDXOW\x03FRGHV\x03VHW\x11\x030RQLWRU\x03VSHFLHG\x03DQG\x03DFWXDO\x03YDOXHV\x03RI\x03inlet side of the heater core, and the other is for the transmission cooler onthe temperature doors in live data.YHKLFOHV\x03HTXLSSHG\x03ZLWK\x03D\x03'6*\x03DXWRPDWLF\x03WUDQVPLVVLRQ\x11Sample Rate: 8.0 - VCDSEngineEngine inlet Label File: 06K-907-425-V1.CLB Basic Settings StopTemperatureoutput IDE05231-Engine temperature management actuatorcontrol of the actuatorGo! Finished correctly I motor N493 Rotary slide 2Show Measuring Data Done, Go BackSupply toN493 Basic SettingradiatorVCDSAdvanced Measuring ValuesSample Rate: 1.3 Turbo!Group UDS requestsBackLoc. Description Actualof theIDE. Coolant temperature 106 CoilIDE. Coolant temperature at radiator outlet: actual. 22.9 CcoolerIDE. Coolant temperature at engine outlet: specifie. 106.5 CBelt drive IDE. Coolant shut-off valve OpenGearCoolant pump IDE. Coolant circulation pump: activation 10.00 %worm RotaryIDE. Transmission coolant valve Openslide 1 Back heating,IDE. Heater support pump: spec. value 65.11% turbocharger Back radiator and gearbox Graph Log Save Done, Go BackN493 Temperature Control Actuator Cross View (Image Courtesy Volkswagen) &RRODQW\x036HQVRUV\x03\x036KXW\x102\x039DOYHV\x03/LYH\x03'DWD"