monitoring oil fluid life

54 GEARS April 2003

Like most areas of the automo-bile, the vehicles lubrication andhydraulic systems have undergone many significant changes andupdates in the past few years. Fordecades the service interval for engineoil and transmission fluid changes werelisted in the vehicle owners manual.Generally two different oil/fluid changerecommendations were listed.Normal was described as highwaydriving, while the Severe changeschedule included cold start usage, stopand go driving, driving in hilly condi-tions and trailer towing. The customerwas supposed to interpret their type ofdriving and change the oil/fluid at theappropriate mileage or time interval.The problem with this system is the fol-lowing:

Very few people ever read theirowners manual!! It has always astound-ed me when some one buys a $100stereo, they spend 5 hours learning howto care for and operate the unit. Butthat same person purchases a $40,000Tahoe and they refuse to even crack theowners manual open. Hence, it is notuncommon at the OE as well as theindependent level to see a customer thathas not changed oil in the last 25000miles!! I cannot count the number oftimes I have seen customers come in forwarranty on their engine and I foundthat the oil had never been changed, andyes we could determine without mucheffort if the oil had been changed.Several times I have personally seenengines with over 60,000 miles on themand the production filter was still inplace on the engine. I actually met aDoctor one time that never changed oil

in his vehicles, he just added oil when itgot low.

A fun one was a guy in a motorhome that wanted a new engine underwarranty. The motor home had 33000miles, the OE filter was still in place,the customer had no receipts for any oilchanges. When we pulled the pan theoil had turned to Jello. Honest, youcould shake the pan and the oil wouldjust wiggle! When you turned the panupside down the oil stayed in the pan!In addition some customers were prettysneaky , after their engine failed theywould drain the oil and replace it withfresh oil and a filter. They really must

of thought we were as dumb as yourshoes, as again it is not difficult todetermine is the engine seized before orafter the oil was changed!

Another fun one was the guy thatwanted his truck bought back for trans-mission problems. It was a 1 ton X cabwith a 4L80E. He had gone through 8transmissions in less than 35000 miles.He owned a salvage yard and traveledbetween the two cities that he ownedyards in. Upon inspecting his truck Inoticed he had a 5th wheel hitch in theback of the bed. I asked to see his trail-er, which was loaded and ready foranother trip. It was a 40 foot tri-axle

by Steve Garrett

Garrett-monitorng_oil.qxd 3/24/03 4:43 PM Page 54

enclosed trailer. I asked if I could drivethe truck and trailer combination toEvaluate what was happening to thetransmissions. I hooked up my instru-mentation and off I went. The thing thecustomer did not know at the time wasmy destination, the scales.

I weighed the trailer, it weighed45,000 lbs!!! Not even a heavy dutytruck is designed for that kind ofweight. The customer was not happywhen I showed him in the owners man-ual the loaded towing specs for histruck and informed him that we weregoing to void any future warranty forthe vehicle.

Most everyone fits into the severeduty schedule based on their drivinghabits but they service their vehicle asthough their driving habits fit the nor-mal schedule.

As I am sure you are aware, baseoil does not wear out it simply getsdirty, although its additive packagemay degrade with use. Degradation ofthe additive package and the fact thatthe oil gets dirty is the main reason theoil/fluid needs to be changed. The typeof driving will have the greatest impacton the life of the oil/fluid.

The quality of the filter you use ona vehicle has a dramatic impact regard-ing how long the oil/fluid will stayclean. The transmission filter isdesigned to filter all of the fluid beforeit enters the hydraulic system. Theengine oil filter does not filter all of theengine oil in the vast majority of appli-cations. Instead, most engine oilingsystems are designed to filter some-where between 10-30% of the engineoil at a given time. This means a signif-icant amount of an engines oil is not fil-tered for a considerable period of time.Therefore the quality of the filter youuse is extremely important if you wantyour engine to last. Beware all filtersare not created equal. Some of themost common names in the filter mar-ket are some of the poorest quality fil-ters. Do your self and your customer afavor, research filters on the internet orgo to your local NAPA store and look attheir filter display. The display showsseveral name brand filters that are cutapart so you can see what is inside, youwill be amazed. To find the filter stud-ies on the internet search the key words

engine filter.Starting in the early 90s GM intro-

duced a system that was designed tomonitor the degradation of the engineand transmission lubricants on manyvehicle applications. This system wasdesigned to assure that the customerwas aware of when his/her engine oiland transmission fluid required service.The system was designed by thefluid/engine/ transmission engineers atGM. Engineers ran countless models tomeasure how long the oil/fluid wouldlast using the OE filter. The oil/fluidlife monitoring systems are designed totake into account the vehicle operatingconditions and the driving habits of thecustomer. So just how does the systemwork?

SYSTEM OPREATIONEach engine and transmission

application was tested to determine thedegradation rate of the oil/fluid for var-ious operating conditions. This baseline information is then loaded in thePCM/ECM software. The PCM/ECMsoftware has a preprogrammed numberof crankshaft rotations stored within itsmemory. Once the block of storedcrankshaft revolutions has been usedup, the PCM/ECM will turn on theservice engine oil or service transmis-sion fluid indicator.

The PCM/ECM monitors the num-ber of crankshaft rotations and the spe-cific way the vehicle is driven. If thevehicle driving conditions were mostlyhighway the number of miles the vehi-cle could be driven will be greater thanfor the customer that drives aggressive-ly or in stop and go traffic. TheECM/PCM subtracts crankshaft revolu-tions from the block of crankshaft revo-lutions as the engine runs. Based onthe following driving chacteristics thePCM/ECM will increase the rate atwhich it deducts revolutions from itsrevolution bank:

Cold start operationHigh ambient temperaturesAccelerationHigh engine loadHigh transmission temperatureHigh engine temperatureHigh RPM operationCalculated oil temperature

The penalty points that areassessed by the PCM/ECM reduce thenumber of crankshaft rotations requiredto illuminate the service indicator. Thecustomer may notice that the mileagewhen the change oil/fluid indicator firstcame on will vary between oil/fluidchanges. This is normal as the numberof penalty points assessed by the sys-tem will vary based on how the vehiclewas operated since the last oil/fluidchange. It should be noted that theoil/fluid life monitor has no way ofknowing if the vehicle had been operat-ed in dusty conditions. If the vehiclewas operated in dusty condition theoil/fluid should be changed based onthe severe schedule.

How the indicator is turned onvaries based on the application. Someapplications have the indicator hardwired to the PCM/ECM while othersutilize serial data transmission betweenthe PCM/ECM and the DIC (DriverInformation Center) or the IPC(Instrument Panel Cluster).

Since this system has the ability todisplay an indicator message or lamp,the customer will need to have theoil/fluid monitor memory reset if theoil/fluid is changed. This is accom-plished on GM vehicles using severaldifferent methods including:

Buttons on the DICButtons on the radioButtons on the IPCHidden buttonsThe accelerator pedal

Since each system utilizes a differ-ent type of reset procedure it is impor-tant to understand how to reset eachtype and year of vehicle. Listed on thenext few pages is how to reset the oillife monitor on different types/years ofvehicles.

56 GEARS April 2003

Monitoring Oil/Fluid Life


58 GEARS April 2003


1996-03

Buick LeSabre, Buick Park Avenue, Oldsmobile 88, CadillacDeville, Cadillac Eldorado, Oldsmobile Aurora, CadillacSeville, Buick Century, Buick Regal, 1997-03 ChevroletCorvette, Pontiac Bonneville (equipped with a DIC)

Turn on the Ignition switch, engine offPress the Trip button (Engine, Gage, Info or mode button

depending on application) on the DIC to view the choicesavailable.

Stop pressing the appropriate button when "oil life remain-ing" or "oil life index" is displayed.

On the DIC press and hold the "reset" button for at least 5seconds. The oil life should change to 99-100% on theDIC (on some applications the display will read XXX orreset)

1997-03

Pontiac Grand Prix with a trip calculatorTurn on the Ignition switch, engine offPress the mode button on the trip calculator until a light

appears next to the "Oil Life" display.Press and hold the "Reset" button on the trip calculator until

the oil life changes to 100%.

1999-03

Pontiac Grand AM, Oldsmobile AleroTurn on the Ignition switch, engine offPush the reset button located on the drivers side IP fuse

blockThe change oil light will flash, press the reset button 1 more

time. Chimes will sound indicating the change oil message has

been reset.

2001-03

Pontiac Aztec, 2002-03 Buick Rendezvous with a DICTurn on the Ignition switch, engine offPress and hold the mode button on the DIC until the display

reads "Oil life left"Press and hold the SET button until 100% is displayed.3 chimes will sound and the change oil message will go off

in the DIC if you were successful in resetting the monitor.

2001-03

Buick Regal with a DICTurn on the Ignition switch, engine offDisplay engine oil life on the DICPress and hold the DIC reset button for at least 5 seconds.

2001-02

Cadillac EldoradoTurn on the Ignition switch, engine offPress the info button until "Oil Life Left" is displayedPress and hold the Reset button until the index reads 100%.

2003

Cadillac CTSTwo methods may be usedWITH BASE AUDIO SYSTEMTurn on the Ignition switch, engine offPress the info button on the DICOnce the oil life is displayed on the DIC press and hold the

CLR button. The oil life index will reset to 100%.WITH ON STARTurn on the Ignition switch, engine offTurn on the Audio system on using the PWR/VOL knob on

the lower left of the DICPress the info button on the left of the DIC displayTurn the TUNE/SEL knob located on the lower right of the

display until engine oil life is displayed. Press the knobonce to select the engine oil life function

Press the multifunction reset button in the upper right cornerof the display. The Display should now display 100% indi-cating the oil monitor has been reset.

1999-03

Pontiac Montana, Oldsmobile Silhouette, Chevrolet Venturewith a DIC

Turn on the Ignition switch, engine offPush the trip reset button in the DIC until "OIL" is displayed

on the DIC.Push and hold the reset button for at least 5 seconds The

number that was displayed will change to 100 indicating100% oil life.

Turn off the ignition switch.

1997-03

with a DIC, Pontiac Grand Prix, Buick Century, Buick Regal,Chevrolet Lumina, Oldsmobile Intrigue, Chevrolet MonteCarlo, Chevrolet Tahoe, Chevrolet Suburban, 1999-00Chevrolet Venture, GMC Yukon, GMC Denali, HummerH2, 2002-03 Oldsmobile Bravada, Chevrolet Trailblazer,GMC Envoy, 5500-6500-7500-8500 series medium dutytruck, 2003 560 medium duty truck, 2000-03 B7 mediumduty truck, 1999-00 Pontiac Montana, OldsmobileSilhouette 1999-00, Chevrolet Avalanche, GMC Sierra,Cadillac Escalade, Cadillac Escalade EXT, 2001-03Pontiac Aztec, 2002-03 Buick Rendezvous

Turn on the Ignition switch, engine offPress and release the accelerator pedal fully 3 times within

5 secondsThe change oil as well as possibly other messages or lamps

will flash.Turn off the ignition switch, the index has now been reset to

100%.If the light comes back on repeat the procedure.

(Continued on page 62)


62 GEARS April 2003


1999-02

Chevrolet Camaro, Pontiac Firebird/TransAMTurn on the Ignition switch, engine offPush the Trip/Oil Reset button located in the IPC for at least

12 secondsThe oil change light will flash and then go out.

1991-2000

Buick LeSabre, Buick Park Avenue without a DICTurn on the Ignition switch, engine offPress and hold the Oil reset button located in the glove box

(or under the dash next to the heater box on the passen-ger side). Hold the button for 5-55 seconds.

The change oil indicator will now flash 4 times indicating themonitor has been reset.

1989-91

Cadillac Eldorado, SevilleTurn on the Ignition switch, engine offPress the ENG DATA button until oil life index is displayedPress ENG DATA and RANGE simultaneously until the mon-

itor resets to 100.

2001-03

Chevrolet Impala, Monte CarloOptional Method using the radioTurn on the Ignition switch, engine off, Radio OFFPress and hold the TUNE DISP button on the radio until

"SETTINGS" is displayedPress the SEEK PSCAN up or down arrow to scroll the main

menu.Scroll until "Oil Life" appears on the display.Press the 1 Prev or 2 Next button to enter the sub menu.

Reset should now be displayed. Press the TUNE DISP button to reset the monitor. A chime will now sound indicating the oil life monitor has

been reset.Scroll till EXIT appears on the display. Press the TUNE

DISP button to exit the reset functions.

1992-93

Cadillac Eldorado, SevilleTurn on the Ignition switch, engine offPress INFORMATION until the oil life index is displayedPress STORE/RECALL until the oil life monitor resets to

100.

1989

Oldsmobile Toronado/TrofeoTurn on the Ignition switch, engine offPress the ENG DATA button until oil life index is displayedPress ENG DATA and GAGE simultaneously until the moni-

tor resets to 100.

1990

Oldsmobile Toronado/TrofeoTurn on the Ignition switch, engine offPress the ENG DATA button until oil life index is displayedPress RESET and ENTER simultaneously until the monitor

resets to 100.

1991-92

Oldsmobile Toronado/TrofeoTurn on the Ignition switch, engine offPress the OPTIONS button until oil life index is displayedPress RESET and ENTER simultaneously until the monitor

resets to 100.

1989-92

Oldsmobile Toronado/Trofeo with visual information centerTurn on the Ignition switch, engine offPress the INFO key and then the OIL LIFE key until oil life

index is displayedPress RESET until the monitor resets to 100.

(Continued from page 58)


GEARS April 2003 63

1989-93

Cadillac AllanteTurn on the ignition switch, engine offPress the RANGE button until the oil life index is displayedPress AVE SPEED and RANGE simultaneously until the oil

life monitor resets to 100%.

1991-1995

Oldsmobile 98/88 with a DICPress the reset or test button in the center of the IPCPress the Oil buttonPress and hold the Reset button for at least 5 seconds.

1989-91

Cadillac Eldorado, SevilleTurn on the Ignition switch, engine offPress the ENG DATA button until oil life index is displayedPress ENG DATA and RANGE simultaneously until the mon-

itor resets to 100.

1993-05

Cadillac, with a Northstar engine (Resetting theTransmission Fluid monitor Using onboard diagnostics

Turn on the Ignition switch, engine offEnter on Board diagnostics, Choose PCM outputs. Select PCM output parameter PS15 Use the warmer button to increase the fluid life in 1 degrees

increments, while the cooler button will decrease the fluidlife. This feature allows you to reset the fluid life to whatever percentage you desire between 1 and 100%.

Cycle the key off for at least 30 seconds to store the valueyou set in the above step in memory.

NOTE: On some applications, the engine and/or transmis-sion fluid life can be reset with the use of a scan tool.

Well as you can see, this type of system is becoming moreand more popular. In the years to come most of the vehi-cles coming into your shop will be equipped with somesort of monitoring system. If you are ever in doubt as howto reset a monitored system look in the vehicles ownersmanual, you know the book in the glove box that is stillwrapped in its original plastic!

1993-03

Cadillac, Oldsmobile Aurora with a Northstar engine(Resetting the Transmission Fluid monitor Using the DIC

Turn on the Ignition switch, engine offPress the Trip button (Engine, Gage, Info or mode button

depending on application) on the DIC to view the choicesavailable.

Stop pressing the appropriate button when "transmission oillife remaining" or "transmission fluid life index" is dis-played.

On the DIC press and hold the "reset" button for at least 5seconds. The oil life should change to 99-100% on theDIC (on some applications the display will read XXX orreset).

1991-93

Cadillac Deville, FleetwoodTurn on the ignition switch, engine offPress RANGE and FUEL USED buttons simultaneously to

display the oil life indexPress RANGE and RESET simultaneously until the change

oil soon light flashes. The oil life monitor is now reset.


monitoring oil fluid life

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