Mode $06 is a PCM and scan tool diagnostic mode that may
Contents
1. 2003 F ord F 150 V8 rolls into your shop with the customer complaint that the vehicle runs rough at times This occurs mostly under light to moderate acceleration and the Check Engine light is not illuminated Perhaps the thought of a no code driveability problem sig nals a difficult day ahead But today you re up for a good chal lenge and you can t get to the gravy work until this job is done You road test the vehicle under a light to moderate load and you re able to duplicate the symptom which is good news At least you re not chasing a phantom problem Based on the symptom it appears the vehicle has a misfiring cylin der You roll back into the shop and continue following a good diagnostic procedure by performing a thorough visual inspection of items related to engine performance U nfortu nately you note no obvious issues So what s next If the Check E ngine light were illuminat ed the next logical step would be to connect a scan tool and check for diagnostic trouble codes But the light is not on Where should you go from here If this were a GM vehicle you d connect a scan tool and review the engine misfire data parameters to pinpoint the cylinder that s causing the intermittent misfire But this is a Ford and misfire data parameters are not available in the enhanced data stream You decide to connect a scan tool anyway and to check for possible pending trouble codes Unfortunately no codes are stored F or many techs2. this is where a good day usually turns bad really fast But not for you today Perhaps you recently at tended a scan tool seminar where they discussed using M ode 06 data on F ord vehicles to locate a cylinder that s causing a misfire and now is a good time to use what you learned In case you have not heard of M ode 06 data let s review M ode 06 data Is one of the ten diagnostic modes or cate gories associated with the OBD II Generic system and is primarily found in the OBD II Generic section of your scan tool say primarily because a few vehicle manufacturers now also include M ode 06 data in their factory scan tools M ost OBD II Generic scan tools provide a description of the category but not the actual mode F or example if the Check Engine light is illuminated and you need to retrieve the fault code you select the description Read DTCs which really means you ve selected M ode 03 Fig 1 on page 38 is of a scan tool screen that displays the different mode numbers and a description of each mode M ode 06 data is the raw test values the OBD II system uses to evaluate the operating status of various components and systems in the engine management system Engineers program specific limit values for systems and components in order to determine when a fault code should be set For example the screen capture in Fig 2 shows M ode 06 data from a Ford F 150 The first line shows data for Test ID TID 01 and Compon
3. third fir ing events also show unstable secondary burn F ig 6 above shows a few more ex linet oo o S00 utecs Me ae ct 1006 OC iin Ene hk b Tas exh LE j 4 bt Fig 6 AC 0 P Esm es adapter can be pres used to quickly pin eee point shorted coils The image at right is a known good ig nition pattern the others are exam ples of shorted coils The diagnostic focus is on the pri mary ignition sec tion of the pattern Quik Check lt wire itini Rir amples of shorted coils Fig 7 below shows the misfiring cylin der and its cause a damaged ignition oil boot The white area in the photo indi cates a burn through in the rubber boot where the secondary voltage escaped Fig 7 The intermittent misfire issue on this Ford vehicle was a hole in the side of the boot The damage in this example is very obvious but similar carbon traces in side the boot also may occur If you re not careful swapping coils will make you think the problem magically went away It didn t it may appear a few days or weeks later 44 MOTOR july 2011 Primary Normal Primary Shorted Inside the rubber spark boot is a spring connecting the coil to the spark plug When the boot becomes soft the voltage is able to find a path of less resistance M ost of the time the damage is not that obvious In some cases a carbon trace will develop inside the boot and the sec ondary voltage will travel down the sid
4. 071 Boe 1159 50 pm ET August 37 207 Program Period Open to legal residents of the 50 US states LE and Canada pexcluding residents of Desbach 16 years of ape or alder or fhe age of majority in their stain prone of residence Particgpanis meri be achvely employed fuli of part time as a Gourlerperson Professional Technician ot Wholesale Destributor Eligible Particrpant a a ead ain aenar rs Copy Bulo ropair comau a Ahaaa aulo paris disiribulor To pariaman ved www FAM Challenge com fe Website curie complete fhe online registration awd sucess tlh campile all tiree H monthly video hiera during the Program Formed Eligitte Paricinans rceve one 1 evry itt amindan drawing tot each duccesslully competed vides Limit ane entry per parema per sueccessfelly Completed risa Dadi of wining depend on fhe total number of ebaH entries ceisd Five 5 Grand Prei SLE US valie moran Express branded fieward Card inconties Other Thee first 4 500 Eboible Particpants who seccessdully complete all three 13 video tutonals dung the Program Poriod will morio a Carhartt Long Sterve Workownar T Stert Incentive Offer ARV 96 00 U 5 905 60 OND Canadian residents must comecty goer a kil iing queso aed CA nasi os Bey Sobers to complote Gica Rates galah at tha Werte tie Sponsor Hono veel Consumer Preducts Hea a diviion of Honeywell Intentiabonal lie 29 Cid Piy Poel Deroy CT RES USA O AT Horeyeanl iienaa ine Circle 25 38 MOTOR
5. July 2011 AHTS Honda Fomenge Car Civic LX LL Lal Pa 2 es Identification Vehicle Info Diagnostics Service Info Global OBD Il Global OBO M Test Stepa Sekechion of required functor Continue wit Continue Mode 2 Freeze Frame Mode VTA road OTSs Sci 4 Liner OTs lor a iyeba aaa 5 Cachan Ganon Gaba Mode 6 Tent data sporad momit systems oe A ACLS Mace O Yepha RA Back Fig 1 Mode 06 data is available on most OBD II Generic scan tools but the location and description of the information will vary from tool to tool In this ex ample Mode 06 is clearly labeled for easy access Consult your scan tool man ual for additional details about the location of Mode 06 data eT he Fuel Tank level must be above 15 for misfire monitor operation It s not uncommon to be working on a ve hicle that s low on fuel but if the fuel level is less than 15 misfire monitor ing is suspended Some technicians are in the habit of Swapping coils clearing PCM memory and then road testing the vehicle for component or fault verification After clearing the PCM memory a Profile Correction must be learned to correct Velie Heath 17 MAY FOLL G9 PH Test 10 TTB 00 ich te iian gender Bho veel ape corel ant 01 ich ba loan canser Graho yeftoge omma ii ins ii fiz 409 25 im 08 m 0 me me sas 40s 07 joa fen g tiseeeeceeusi Tae EEEEEZEESE Zz nooo o leo Fig 2 Mode 06 data will be disp
6. What s the best way to test for intermittent ignition misfires Con nect an engine analyzer lab scope to the misfiring cylinder before disturbing the connections between the ignition coil spring boot and spark plug M ost scope manufacturers offer a variety of ways to access ignition signals and you need to pick your best display options Fig 4 on page 40 shows a secondary ignition pattern taken from a Ford F 150 at idle with an intermittent misfire using a coil on plug C O P wand The C Q P secondary ignition pattern looks very similar to a single cylinder distribu tor ignition pattern and they are with one exception Ford uses a multispark strategy at idle soeed This will go into a single spark program off idle which is useful to know if you re conducting loaded diagnostics ve labeled the common sections of the ignition pattern for general review but here are a few tios when dealing with F ord misfires elf you have a DTC for a specific cylinder and the code comes right back after you clear it the most likely cause is a shorted coil or a secondary ignition is sue that s so bad you might even hear it arcing If you listen closely Shorted coils are easy to pick out using the primary ignition pattern eC O P ignition systems are more sen sitive to Issues in the secondary ignition area The point labeled Start of Burn in Fig 4 is a good spot to focus on when looking for resistance in the boot s
7. e cause of the misfire There are many in dividual issues that can create cylinder misfires and they fall into three basic categories fuel ignition and engine mechanical This is where deductive reasoning will save you time by helping you deter mine which checks or tests should be performed first We know from our road test that the misfire is not present at all times so we need to consider what can cause Intermittent misfires Or maybe in this case we should consider what would cause a constant misfire condition By having this information we can determine where to look for in termittent misfires Let s look at fuel first If the fuel in jector were shorted we would likely have an injector fault DTC and a possi ble P0303 Service information would point to resolving the fuel injector fault first which would resolve the P0303 If the fuel injector were providing too much or not enough fuel a P0171 or P0174 fuel mixture DTC would be stored If the fuel injector in question l Siri Ihot Timely tmiece ghee Miata E 25 00 DE aj ad was not providing any fuel at all and is not shorted then a P0303 would be present and perhaps a P0171 lean mix ture fault as well Based on this reasoning the fuel sys tem is not likely to be the source of the intermittent misfire There are always exceptions to the rule and possible wild card ideas might be water in the fuel or fuel injector wiring circuit issues but neit
8. e of the spark plug to ground Testing the secondary ignition before disturbing the coil will allow you to see what s truly at fault In this example we determined the source of the problem was In the secondary ignition area and a new boot and spring should fix the problem In review the key to quickly finding intermittent misfire issues is having a consistent strategy and being comfort able with your equipment Knowing how to use M ode 06 to find the cylin der that s misfiring is a critical step in the process and takes only a few mi This article can be found online at www motormagazine com
9. ent ID CID 11 which relate to Bank 1 Oxygen Sensor functionality The power train control module PCM uses a special fuel control switching routine to test the O2 sensor The Min and M ax columns display the programmed threshold values for pass or fail The Actual column displays the value for the last test 36 MOTOR July 2011 hotoillustration Harold A Perry images Thinkstock amp Wieck Media MISFIRES By Bos Parrencal EN a 4 i P Mode 06 is a PCM and scan tool diagnostic mode that may or may not be familiar to yo Here we demonst ate how data displayed nh this mode can pe Wed to pinpoint the sourc of an intermittent z misfire on Ford vehicles performed In this example the Actual value is 729 which Is greater than the M in value of 512 which means the O2 sen sor passed the last test f the Actual value was less than 512 the PCM would likely set a P0133 DTC Bank 1 Slow Re sponse and illuminate the Check E ngine light Further down the chart are Test ID numbers without a description Why In the early stages of OBD II vehicle manufacturers were not required to use a standardized M ode 06 labeling format so for the scan tool to decode the data correctly you need a detailed year make model and engine size database If your scan tool displays only the raw data without definitions there s no reason to panic most shop information systems provide M ode 06 defin
10. her of those is a likely scenario Skipping over ignition problems for a moment let s move on to mechanical engine issues M echanical issues like low compression jumped timing and valve train problems are more likely to create a permanent misfire condition Again exceptions to the rule and all that and other causes of a misfire could be stick ing valves or faulty lifters but don t be lieve these are the most likely causes You probably already have a good idea that the ignition system is the most likely cause of the intermittent misfire but which part of the ignition system is at fault PCM ignition coil coil boot spring or spark plug Some techs are coil swappers If you are too don t worry you re not alone But how often have you have swapped coils only to find that the misfire is gone on the original cylinder and all you did was trade one misfiring cylinder for an other The misfire may be gone for only a short time then shows up in the swapped position or returns to the origi nal cylinder Swapping coils is not a very accurate 42 MOTOR july 2011 Fig 5 These screen captures and photo show another method of testing Ford ignition coils A lab scope is con nected to the control side of the coil A low current probe can be used to check for a shorted coil but is not much use for secondary ignition tests or efficient way to locate the source of a misfire and might end up wasting valu able time
11. itions The good news is that a standard has been established and you ll see this new format on most Controller Area N etwork CAN OBD II vehicles N ow let s get back to our misfiring F ord F 150 The next step is determining which Test ID s are related to the mis fire monitor Let s take another look at Fig 2 because it might be possible to figure this out without referring to the service information L ooking at the chart you ll notice there are a series of 51 Test ID s with the associated Component ID s numbered 01 through 08 A quick guess would have been right The 51 Test IDs are related to the misfire monitor and Component ID s 01 through 08 represent cylinders 1 through 8 F or future quick reference early model F ord systems use 51 to monitor misfire later non CAN systems use 53 and CAN systems use 0B for the history last 10 drive cycles and 0C for the current last test performed Test ID 50 is for misfires that cannot be attributed to a specific cylinder and will normally result in a P0300 DTC being set In Fig 2 all the 51 TID s except CID 03 show 0 which means the misfiring cylinder in question is cylinder 3 The M ax limit in this case is 1638 and the Actual value is 1177 which means that during the last trip misfires occurred but they had not exceeded the limit This is why we have no DTC for cylinder 3 Once the Actual value exceeds the M ax limit a DTC will be stored in this case a P0303 would be
12. layed in many formats This scan tool capture shows all the available items in a simple easy to read chart If your scan tool doesn t provide all the definitions pertaining to Mode 06 consult your service information for details for mechanical variations in the engine This might require an extended road test on later model vehicles The misfire section of the OBD document pro vides a key piece of information that will help reduce the amount of time it takes for Profile Correction Learn to complete The PCM needs to see at least three 60 to 40 mph no braking decelerations for Profile Correction Re learn which means a standard road test around the block will not get this done eM any techs have wondered why on some F ords the Check E ngine light does not come on right away when a misfire is present This is primarily due to the misfire count not exceeding the limit But there s another way F ord protects the catalytic converter during misfire conditions The misfire section of the OBD II document explains that if the PCM determines a cylinder is misfiring the fuel injector can be turned off to protect the catalyst from damage Once the fuel injector is turned off the cylin der is now basically an air pump which reduces the potential for catalyst failure The key to efficient driveability diag nostics is thorough system understand ing Knowing when where and how a test is performed is critical for success Consul
13. pring and spark plug If the Start of Burn voltage is higher than what s shown here there s more resistance if the Start of Burn volt age is lower there s less resistance e ntermittent issues are generally go ing to show up in the secondary ignition section but most of the time you ll need to road test the vehicle Don t spend too much time looking for a misfire in Fig 4 because none is present Remember the misfire happens only when the vehicle is driven so we need to attach a C O P device suitable for road tests and retest while driving If you don t have a suitable road test attachment available Fig 5 above shows an alternative method which entails con necting your lab scope to the control side of the ignition coil The image you re Chick Choc looking for is similar to the blue trace which is basically the secondary pattern from Fig 4 displayed in a lower voltage range A low current probe Is also con nected but is not necessary for intermit tent secondary misfire issues The left image in Fig 5 shows the cylinder without a misfire The right im age is captured as we begin to acceler ate the vehicle duplicating the condi tions that caused the customer s com plaint The first secondary ignition firing Primary Shorted TE TH gee rei l i 7 event is turned into a sea of solid blue and it looks like we have times where the secondary voltage goes high and then very low The second and
14. stored once the limit is exceeded and then the Check En gine light will illuminate Keep in mind the Check E ngine light will react differently depending on the severity of the misfire F or example it will illuminate steady for a Type B misfire or flash if there s a Type A catalyst damaging misfire Once again the car manu facturer will establish the limits for Tyoe A and Type B mis fires F ord offers a free resource at www M otorcraftservice com that details how its OBD II systems operate Click on the OBD Theory amp Operation tab along the left side of the page You ll find a list of OBD summary documents from 1996 to the current model year 2011 including diesel engines The documents offer interesting insight into how F ord OBD II monitors operate including monitor sequence which sensors are involved how long the monitor runs typi cal monitor conditions and failure criteria F ollowing are a few key points about F ord misfire moni toring found in these documents July 2011 MOTOR 3 7 For no charge you ll take three different 15 minute modules instructing and testing you on subjects like oil filter anatomy engineering testing and extended oil changes Finish all three modules to earn rewards and for a chance to win prizes Carhart Long Sleeve DON T FAIL YOUR ENGINE NO PUSICHASE HECESSMARY WHO Mi QUEREC AND WHERE PROMEITED The FAAM Challenge Program nas T0101 im Besser Tiree ET on Some 1 2
15. ting these documents will pro vide insight that goes beyond trouble tree charts In no code driveability situations us ing M ode 06 data is the key to deter Fig 3 Ford dealership technicians use a factory scan tool to locate the mis firing cylinder The dropout in the pattern shown in this screen capture indi cates that cylinder 3 is not contributing as much as the others The good news You don t have to purchase a factory scan tool to get the job done mining which cylinder or cylinders are misfiring If you re not sure where to find M ode 06 data on your scan tool review the user s manual You might be wondering how dealer ship technicians deal with cylinder iden tification issues Fig 3 above is a screen capture from the F ord factory scan tool F ord offers a Power Balance test proce dure which shows all cylinders in a chart and compares per cylinder rom to a baseline In this example cylinder 3 Start of Burn Burn Time Primary Ignition u TS 0 Chae prem r prm Banh T Fig 4 This is a secondary ignition pattern from a Ford with an intermittent misfire at idle The pattern is easy to get when you use a C O P adapter as shown in the photo 40 MOTOR July 2011 shows reduced rpm which indicates that cylinder 3 is not contributing as much as the other cylinders We don t know the cause of the misfire at this point but we know cylinder 3 needs to be checked The next step is to determine th
Download Pdf Manuals
Related Search