Ford Power Stroke Diesel No-start Diagnosis
Contents
1. Don t Start Something You Can t Finish By Bos PATTENGALE service opportunities on diesel powered vehicles are on the rise If your shop is looking for additional revenue taking on the oil burners could be the ticket But to be successful you ll need the right tools and training ow do you approach a fa miliar no start or drive ability problem Do you jump right in relying on past knowledge of com mon problems or do you follow a set diagnostic strategy to ensure nothing is overlooked What about when a vehicle manufac turer makes changes to the engine man 36 MUTOR November 2011 agement system D o you take time to understand the system first or do you dive right into the diagnostic process hoping your experience wins out What happens if your first couple of educated guesses don t resolve the problem Effective and efficient repair of to day s vehicles requires an understand ing of how each system operates be fore the diagnostic process begins It s Photoillustration Harold A Perry images Thinkstock amp Wieck Media November 2011 MOTOR 37 Oil Reservoir hi of High Pressure Pump High Pressure Oil Pump High Pressure Oil Rails is Ca LITE I tints Oil Cooler ICP Sensor tlt tite Fuel Injectors ee CSA ATT it INT II po N A TT a PR Sensor lt Drain to Crankcase Fig 1 This illustration shows the low pressure and high2. Check the low side oil pump pressure Al so pay close attention to the oil filter and related check valves Step 2 Using a scan tool with IPR bidirectional con trol open and close the IPR to see if any pressure change occurs If nothing hap FORD POWER STROKE DIESEL NO START DIAGNOSIS pens the IPR will need to be checked Step 3 The photo below shows an adapter used to check for leaks at the ICP port The ICP is removed and the adapter air hose are installed The shop air pushes the oil out of the high pressure system through the IPR into the oil pan Once you hear the air flow ing easily use a scan tool to command the IPR to 85 which closes off the high pressure system If the airflow does not decrease check the IPR Now Here are two test devices for diagnosing a no start condition on a Ford 6 0L Power Stroke diesel engine you cannot live without The adapter with hose at tached top photo is used to check for high pressure leaks at the ICP The two block off tools above check the high pressure pump s deadhead pressure 46 MOTOR November 2011 use a stethoscope and listen for leaks Step 4 If no leaks are found use the high pressure deadhead isolation tools to determine if the high pressure pump can produce sufficient pressure F ollow the manufacturer s recommendations for the proper test sequence The pump should be able to produce 1500 psi while cranking and IPR over 60 One quick check to
3. These are graphical examples of how the ICP IPR and rpm work together The screen capture on top is from a known bad vehicle that will not start which had an oil pressure leak the screen capture above is from a known good vehicle 44 MOTOR November 2011 shows the vehicle running after warm restart with the ICP pressure high But the pressure will continue to lower to the desired level The Inj Press Reg percentage will continue to decrease until the ICP desired pres sure is reached The screen capture on the bottom shows that the vehicle will not start The voltage values are normal rom is greater than 120 sync from the FICM isnor mal The ICP is below 500 psi and the Inj Press Reg has reached 85 which means there s an issue in the oil system Fig 3 graphically dis plays two vehicles while cranking The recording at the top shows a vehicle that will not start The red verti cal lines relate to the values below the graph In this case rpm is good but ICP is not capable of reaching 500 psi and the IPR is fully closed The bottom record ing shows a vehicle that s operating properly The timeline shows that it takes less than 4 seconds to start and stabilize the injection control pressure By now you should start to see a trend After a quick glance at the other parame ters the primary focus should be the ICP and the IPR percentage If the ICP is unable to reach 500 psi you need to determine why Step 1
4. bleshoot ing tips they use a logical process based on how the system functions This article can be found online at www motormagazine com
5. determine if ICP is above 500 psi and the vehicle will not start is to verify that the CP is accurate Simply disconnect the IPR if the vehi cle starts the ICP is out of calibration and should be replaced If vehicle does not start continue with other non oil related issues If you Skipped Steps 4 through 6 on the H ard Start N o Start Diagnostic Guide now would be a good time to review the fuel related items Check fuel quality elec tric fuel pump pressure and fuel pump inlet restriction Keep in mind that one bad injector will not create a no start so if the oil related systems test good the likely cause is fuel related Unfortunately we cannot cover all possible causes and test sequences in detail here so it s important to follow all manufacturer recommendations As for the 6 4L diesel engine one critical difference between it and the 6 0 is that the 6 4L engine does not use a high pressure oil system for fuel injector operation It uses a high pressure pump but it s pressurizing diesel fuel not oil If you decided to connect a scan tool look ing for ICP IPR or FICMSYNC you won t find these parameters You ll be monitoring parameters like pressure control valve volume control valve and fuel rail pressure sensor In order to be accurate and efficient when diagnosing Ford s 6 0L diesel you need to understand the system you re di agnosing The most successful driveability technicians do not rely on trou
6. e you really get to see what s hap pening with the engine management system It lists eight specific parameters that should be monitored while crank ing the engine H Bi een en dasad F guma Fig 2 These screen captures show the critical parameters that should be watched while cranking the engine The capture on the top is from a known good vehicle while the one above is from a defective vehicle 42 MOTOR November 2011 The two screen captures in Fig 2 show the parameters that should be monitored while cranking the engine Keep in mind that if the battery voltage drops below 9 5 volts the scan tool might reset If this occurs correct the battery issue before continuing In this example Engine Oil Tempera ture EOT is included but is not a para meter that needs to be monitored while cranking The initial note on the D iag nostic Guide is checking E OT If it s be low 60 F and the vehicle will not start and the recommendation is to check the Glow Plug System Operation first A V PWR Module Voltage B FICMLPWR FICM Logic Power C FICMVPWR FICM Vehicle Power The Guide specifies 8 volts min imum for all three A B and C but above 9 5 is a real world value If the voltage values are below the recom mended specification this should be corrected first D RPM The form states 100 rpm minimum but a real world value is above 120 rom Low rpm can be caused by electrical issues If the val
7. ec tion pressure regulator IPR This is a duty cycle controlled solenoid that Opens and closes to achieve the desired oil pressure The IPR duty cycle for a normal hot idle engine is approximately 30 In order to maintain the correct oil pressure excess oil is diverted back to the oil pan During engine start up the PCM needs to see at least 500 psi If the pres sure is too low the PCM increases the duty cycle percentage in other words it closes the IPR creating a restriction to increase the oil pressure If the PCM command reaches 85 the IPR is fully closed which indicates a major problem in the oil supply chain The photo above left shows a dam aged IPR where the debris catch screen is almost completely gone IPRs are common failure items and will normally point to additional problems F or exam ple if you find the high pressure oil reservoir screen is damaged then the IPR will likely have debris present and if the IPR screen is damaged or 40 MOTOR November 2011 clogged the high pressure oil reservoir screen Is likely damaged as well After leaving the high pressure oil pump the oil travels through a series of branch tubes standpipes passages EPA During engine start up the PCM must see at least 500 psi If the pressure Is too low the PCM closes the IPR high pressure oil rails and finally the fuel injectors Keep in mind that these con nection points will have O rings sealing the syst
8. em Fig 1 cannot properly demonstrate all the possibilities but if you look at where the lines connect to the components described each point would likely have an O ring O rings should never be reused under any Cir cumstance We ll discuss how to check for leaks later in the article Steps 1 through 6 in the Ford Hard Start N o Start Diagnostic Guide deal with visual inspection engine oil quality intake exhaust restrictions fuel quality and fuel pump pressure and volume Steps 7 through 9 cover checking for di agnostic trouble codes DTCs and per forming KOE O tests E xperienced technicians will check for DTCs first If the following DTCs are present P1378 Fuel Injection Control Module FICM voltage circuit low P0611 FICM Internal Failure P0261 P0264 P0267 P0270 P0273 P0276 P0279 and P0282 All Fuel Injector Cir cuits are low and or U0105 Lost com munication with FICM the most likely cause will be a faulty FICM Powers grounds and connections between the FICM and PCM should be checked pri or to replacement of the FICM In cases where the FICM connections test okay it s always a good idea to check for newer PCM FICM calibrations It s not uncommon to find TSBs where the only fix is updating the controller software FET Tra If no DTCs are present or if the DTCs do not relate to a no start condi tion continue to step 10 Scan Tool Data List M onitoring This is the step wher
9. he high pressure oil pump can deliver up to 3600 psi but only if the low pressure oil system delivers the oil to the high pres sure pump Understanding the low pressure and high pressure oil systems is critical for diagnosing hard start no start problems so let s take a closer look at these sys tems in detail The low pressure oil system begins with the oil pump drawing oil from the oil pan Oil pressure in excess of 70 psi between the pump and oil cooler is vented back to the oil pan The oil travels from the oil pump to the oil cooler and any pressure greater than 25 psi is diverted around the oil cooler to the oil filter The benefit is pro viding an alternative oil flow path during high oil flow conditions Photo courtesy Automotive Training Group Inc Ae E l a nn r N 2 i This is what can happen when a customer skips preventive maintenance Oil sludge builds up and can damage the reservoir filter screen Once the screen is compromised debris can enter the high pressure pump The oil travels from the oil cooler to the oil filter and any pressure greater than 20 psi bypasses the oil filter and travels to the high pressure reservoir The oil filter housing contains two criti cal valves One is an oil change drain valve that opens when the oil filter is Understanding the low and high pressure oil systems is critical for diagnosing hard start no start problems removed a
10. llowing the oil to drain back into the pan the other is an antidrain back valve that uses a one way check valve to keep oil in the housing with the engine off and the filter installed This ensures that oil is available on initial Start Ups The oil travels to the high pressure reservoir where approximately 1 quart of oil is stored The high pressure oil pump draws oil from the reservoir through a 3 in screen designed to catch debris The photo above shows what can happen when preventive maintenance is neglect ed Keep in mind that once this screen is damaged debris will enter the high pressure pump and be carried through the high pressure system The high pressure oil pump is driven by the camshaft and produces the high pressure oil needed to properly operate the fuel injectors The pump is capable of producing more volume and pressure than is needed for normal operation and the excess volume is controlled by the powertrain control module PCM N ext in line is the injection control pressure ICP sensor which measures the oil pressure leaving the pump and reports this to the PCM The PCM uses November 2011 MOTOR 39 Here are two examples of where oil pressure may be lost in the high pressure system Injection pressure regulator IPR damage left photo and O ring issues right are very common causes of hard start and no start complaints the information from the ICP sensor to regulate the oil pressure using the inj
11. pressure oil systems for the 6 0L diesel engine The fuel system must have the correct oil pressure to operate so oil related problems are common causes of hard start no start issues nice to have troubleshooter tips but there s no substitute for a firm grasp of how the components relate to one an other and what happens when every thing is working right M any assume top driveability tech nicians quickly diagnose problems be cause they re able to complete all the tasks in a fault tree the fastest or be cause they know all the common is sues The truth is they re able to look at the symptoms make a logical deci sion on where the diagnostic process 38 MUTOR November 2011 should begin and then follow the best path for resolution The opportunity to repair diesel vehi cles is on the rise and if your shop is looking for additional revenue diesel repair can be it To be successful you need to have the right tools and techni cians who understand how diesel sys tems work F ord diesel truck repair is a good op portunity It s also an excellent example of how things can change very quickly In the past 10 years Ford has offered four different platforms 7 3L 6 0L 6 4L and now the 6 7L and although the basic combustion process for each is similar how the fuel is supplied to the cylinders is very different This article will focus on a common driveability complaint with the Ford 6 0L diesel engine then explain ho
12. ue is 0 check the crankshaft position sensor CKP E ICP ICP Pressure A minimum of 500 psi is required for injector operation As detailed earlier there are many possi ble causes for low ICP pressure The possible causes could be located in the low pressure or high pressure section F ICP V ICP Voltage Minimum voltage is specified as 80 volt while cranking Zero volts might indicate wiring or connector issues G Fuel PW Injector pulse width defaults to 0 without a CKP signal Range 50015 to 2mS H FICMSYNC No sync from the FICM could be caused by camshaft position sensor CMP or CKP faults The value should be YES after 120 rpm is reached The Diagnostic Guide does not refer ence IPR 1nj Press Reg but thisisa critical parameter for checking the state of oil system health As discussed earlier IPR should be approximately 30 idling hot If the value is higher or has reached 85 there s an issue with the oil system and it s only a matter of time before a hard start or no start issue develops If you service vehicles equipped with this Seg tees eed ie E I 1 ur a a Ge a are Ferd aes Fa LL i I e Ghee Clima H sree emi BITE 1259 mint tect engine on a regular basis it s not a bad idea to check these values N ow let s take a closer look at the two scan tool examples In Fig 2 on page 42 the screen capture on the top alle 2 ed a oe f 8 et ee Fig 3
13. w the 6 4L fuel delivery system differs from the 6 0L H ard start and no start complaints are a common issue with F ord 6 0L diesel engines and experienced techni Courtesy Ford Motor Co cians are able to determine the root Cause very quickly But they can do this only because they understand how the system operates Technicians with limited experience will most likely begin with the H ard Start N o Start Diagnostic Guide devel oped by Ford We don t have the space to reproduce it here but it can be found at http tinyurl com 64dvmu5 This comprehensive guide is designed to pro vide a logical diagnostic flow and help the technician avoid overlooking poten tial issues which from F ord s perspective will ensure that the vehicle is repaired ef ficiently and correctly the first time Technicians using this guide will lo cate the root cause but they may not understand why they re performing the steps listed One example is step 2 Check Engine Oil Level Check for contaminants fuel coolant Correct Grade Viscosity M iles H ours on oil correct level Engine oil quality and level are critical for correct operation of the fuel injectors and a common cause of hard start no start issues Why is the engine oil so critical Fig 1 on page 38 shows a simple oil flow schematic for the 6 0L diesel en gine In order for the fuel injectors to operate a minimum of 500 psi oil pres sure is required for start up T
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