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|Trouble Code: P0300 (3.8L V6 VIN K Auto) |Print this code data[pic] |
|Multiple Engine Misfire Detected | |
Number of Trips to Set Code: 2
OBD II Monitor Type: CCM Details
Indicators: MIL Details
• MISFIRE Details
• MIL Details
Trouble Code Conditions:
DTC P0101, P0102, P0103, P0107, P0108, P0116-P0118, P0121-P0123, P0125, P0336, P0341, P0502-P0503, P1106-P1107, P1114, P1115, P1121, P1122, P1336, 1351, P1361, P1362 and P1374 not set, engine speed from 525-6600 rpm, ECT sensor at 21-255ºF, TP angle steady, system voltage over 10.0v and the PCM detected a crankshaft speed variation in 2 or more cylinders characteristic of a misfire. If the misfire is severe, the MIL will flash on/off on 1st trip!
Possible Causes:
• Base engine mechanical fault that affects one or more cylinders
• Fuel metering fault (high fuel pressure or fuel contaminated)
• EVAP system problem or the EVAP canister is fuel saturated
• EGR valve is stuck open or the PCV system has a vacuum leak
• Ignition system fault (a coil) that affects more than one cylinder
• MAF sensor contamination (it can cause a very lean condition)
• TSB 99-06-04-005B contains a repair procedure for this code
• TSB 03-06-04-030 contains a repair procedure for this code
|PATH: Diagnostics > Diagnostic Routines > Powertrain > Engine Controls - 3.8L > DTC P0300 Engine Misfire Detected |Print[pic] |
DTC P0300 Engine Misfire Detected
|NOTE |
|Applicable vehicles: |
|Bonneville, Eighty Eight, LeSabre (VIN C/H) |
DTC P0300 Engine Misfire Detected
Circuit Description
The PCM has the ability to detect a misfire by monitoring the 3X reference and camshaft position input signals from the Ignition Control Module. The PCM monitors crankshaft speed variations (reference period differences) to determine if a misfire is occurring. If 2% or more of all cylinder firing events are misfires, emission levels may exceed mandated standards. The PCM determines misfire level based on the number of misfire events monitored during a 200 engine revolution test sample. The PCM continuously tracks 16 consecutive 200 revolution test samples. If 11 or more misfires are detected during any 5 of the 16 samples, DTC P0300 will set. If the misfire is large enough to cause possible three-way catalytic converter damage, DTC P0300 may set during the first 200 revolution sample in which the misfire was detected. In the case of a catalyst damaging misfire, the MIL will flash to alert the vehicle operator of the potential of catalyst damage.
Conditions for Setting the DTC
• No VSS, Transaxle, TP sensor, Fuel trim, Fuel injector circuit, ECT sensor, CKP sensor CMP sensor, or MAF sensor DTC(s) set.
• Engine speed between 450 and 5800 RPM.
• System voltage between 9 and 16 volts.
• The ECT indicates an engine temperature between -7°C (19°F) and 120°C (248°F).
• Throttle angle steady.
• The PCM is detecting a crankshaft RPM variation indicating a misfire sufficient to cause three-way catalytic converter damage or emissions levels to exceed mandated standard.
Action Taken When the DTC Sets
• If the misfire level is non-catalyst damaging, the PCM will illuminate the MIL during the second key cycle in which the DTC sets.
• If the misfire is severe enough to cause possible catalyst damage, the PCM will immediately flash the MIL while the misfire remains at catalyst damaging levels.
• The PCM will disable TCC operation.
• The PCM will store conditions which were present when the DTC set as Freeze Frame and Fail Records data.
Conditions for Clearing the MIL/DTC
• The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
• The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
• The DTC can be cleared by using the scan tool.
Diagnostic Aids
The scan tool provides information that can be useful in identifying the misfiring cylinder. If the DTC P0300 is currently stored as DTC status Failed Since Code Clear, the misfire history counters (Misfire History Cyl #1 - #6) will still contain a value that represents the level of misfire detected on each cylinder. The scan tool displayed misfire counter values (Misfire History Cyl. #1 through #6) can be useful in determining whether the misfire affects a single cylinder, a cylinder pair (cylinders that share an ignition coil - 1/4, 2/5, 3/6), or is random. If the largest amount of activity is isolated to a cylinder pair, check for the following conditions:
• Secondary Ignition Wires.
• Check the secondary wires associated with the affected cylinder pair for disconnected ignition wires or for excessive resistance. The wires should measure less than 30,000 ohms (30K ohms).
• Damaged Or Malfunctioning Ignition Coil.
• Check for cracks, carbon tracking or other damage. Also check coil secondary resistance. Secondary resistance should be between 5000 ohms and 8000 ohms (5K ohms and 8K ohms).
• Substitute a Known Good Coil.
• Switch ignition coils and retest. If the misfire follows the coil, replace the ignition coil.
If the misfire is random, check for the following conditions
• Crankshaft Position System Variation.
• Refer to Powertrain Control Module Replacement/Programming .
• The crankshaft position system variation compensating values are stored in the PCM non-volatile memory after a learn procedure has been performed. If the actual crankshaft position variation is not within the crankshaft position system variation compensating values stored in the PCM, DTC P0300 may set. The crankshaft position system variation learn procedure is required when any of the following service procedures have been performed:
o PCM replacement or reprogramming.
o Engine replacement.
o Crankshaft replacement.
o Crankshaft balancer replacement.
o Crankshaft position sensor replacement.
o Any engine repair(s) which disturbs crankshaft/harmonic balancer to crankshaft position sensor relationship.
• System Grounds.
• Ensure all connections are clean and properly tightened.
• Mass Air Flow sensor.
• A Mass Air Flow (MAF) sensor output that causes the PCM to sense a lower than normal air flow will cause a lean condition. Try operating the vehicle within the fail records conditions with the MAF sensor disconnected. If the lean or misfiring condition is not present with the MAF sensor disconnected, replace the MAF sensor.
• Loss of EBCM/EBTCM Serial Data.
• If the PCM stops receiving data from the EBCM/EBTCM, DTC P0300 can set due to a loss of rough road data. Check for stored ABS/TCS DTCs, especially DTCs related to a serial data malfunction. Refer to Diagnosis in ABS/TCS.
• Air Induction System.
• Vacuum leaks that cause intake air to bypass the MAF sensor will cause a lean condition. Check for disconnected or damaged vacuum hoses, incorrectly installed or malfunctioning crankcase ventilation valve, or for vacuum leaks at the throttle body, EGR valve, and intake manifold mounting surfaces.
• Fuel Pressure.
• Perform a fuel system pressure test. A malfunctioning fuel pump, plugged filter, or malfunctioning fuel system pressure regulator will contribute to a lean condition. Refer to Fuel System Pressure Test .
• Fuel injector(s).
• Refer to Fuel Injector Solenoid Coil Test .
• Contaminated Fuel.
• Refer to Alcohol/Contaminants-in-Fuel Test .
• EGR System.
• Check for leaking valve, adapter, or feed pipes which will contribute to a lean condition or excessive EGR flow.
• Low fuel condition.
• Driving with a low fuel condition may create a lean condition which can cause a misfire and DTC P0300 to set. If DTC P0300 was set and the cause of the misfire cannot be determined using the DTC P0300 table, consult with the customer to determine if a low fuel condition was present when DTC P0300 set.
• Extended Idle.
• Excessive open loop operation caused by extended idling or short trip driving may leave deposits on the heated oxygen sensors. The deposits cause oxygen sensors to respond slowly to exhaust oxygen content, affecting fuel control and causing a misfire to be indicated at idle. This condition is not permanent. To determine if this condition is causing the DTC P0300 to be set, review the freeze frame and fail records data for DTC P0300. If the DTC P0300 occurs at high engine speeds, the condition described above did not cause the DTC P0300 to set. If the DTC P0300 occurs at idle or very low engine speeds and at engine coolant temperatures less than 80°C (176°F), the condition described above is very likely the cause of the DTC P0300 being set. The deposits on the heated oxygen sensors can be eliminated by operating the vehicle fully warm at mass air flows above 15 gm/s.
|WARNING |
|Important:: If the level of misfire was sufficient to cause possible catalyst damage (if the MIL was flashing), ensure that the DTC|
|P0420 test is completed and passed after verifying the misfire repair. |
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
2. A malfunctioning injector circuit, crankshaft position system variation not learned condition, or incorrect rough road data from the EBCM may cause a misfire DTC to be set. If any of the indicated DTCs are set with DTC P0300, diagnose and repair the other DTC before using the DTC P0300 table.
3. The Misfire Current Cyl # display may normally display a small amount of activity (0 - 10 counts) but should not steadily increment during an entire 200 revolution test sample period.
4. Depending on the cause of the misfire, the Misfire History Cyl # counter will display a very large number for the misfiring cylinder(s); values for the non-misfiring cylinders will be less than 1/2 as great as the misfiring cylinder(s). When investigating a misfire, always start with items associated with the cylinder(s) that has the largest number of counts stored in the Misfire History Cyl # counter.
5. Steps 5 through 12 check for conditions that can cause a random cylinder misfire.
13. Steps 13 through 22 check for conditions that can cause a non-random or single cylinder misfire.
DTC P0300 - Engine Misfire Detected
|Step |Action |Value(s) |Yes |No |
|1 |Was the Powertrain On-Board Diagnostic (OBD) System Check performed? |-- |Go to Step 2 |Go to the |
| | | | |Powertrain On |
| | | | |Board Diagnostic |
| | | | |(OBD) System Check|
|2 |Are any of the following DTCs also set? |-- |Go to the other |Go to Step 3 |
| |DTC P1200 Injector Control Circuit | |DTC(s) first | |
| |DTC P1336 Crankshaft Position (CKP) System Variation Not Learned | | | |
| |DTC P1380 Misfire Detected - Rough Road Data Not Available | | | |
| |DTC P0300 Engine Misfire Detected | | | |
|3 |Start and idle the engine. |-- |Go to Step 4 |Refer to |
| |Review and record scan tool Freeze Frame data. | | |Diagnostic Aids |
| |Operate the vehicle to duplicate the conditions present when the DTC | | | |
| |was set (as defined by the Freeze Frame data). | | | |
| |Monitor the scan tool Misfire Current Cyl # display for each cylinder.| | | |
| |Is Misfire Current # display incrementing for any cylinder (indicating| | | |
| |a misfire currently occurring)? | | | |
|4 |View the Misfire History Cyl # display on the scan tool. |-- |Go to Step 5 |Go to Step 13 |
| |Does Misfire History Cyl # display a very large value for more than | | | |
| |one cylinder? | | | |
|5 |Visually and physically inspect the vacuum hoses for splits, kinks, |-- |Go to Step 25 |Go to Step 6 |
| |and improper connections. Refer to Emission Hose Routing Diagram . | | | |
| |If a problem is found, repair as necessary. | | | |
| |Was problem found? | | | |
|6 |Visually and physically inspect the PCV valve for improper |-- |Go to Step 25 |Go to Step 7 |
| |installation and for damaged O-rings. | | | |
| |Refer to Positive Crankcase Ventilation Valve . | | | |
| |If a problem is found, repair as necessary. | | | |
| |Was problem found? | | | |
|7 |Inspect the throttle body inlet screen for damage or for the presence |-- |Go to Step 25 |Go to Step 8 |
| |of foreign objects that may partially block the air flow sample | | | |
| |through the MAF sensor. | | | |
| |If a problem is found, repair as necessary. Refer to Throttle Body | | | |
| |Assembly Replacement . | | | |
| |Was problem found? | | | |
|8 |Check fuel pressure. Refer to Fuel System Pressure Test . |-- |Go to Step 25 |Go to Step 9 |
| |If a problem is found, repair as necessary. | | | |
| |Was problem found? | | | |
|9 |Check the fuel for excessive water, alcohol, or other contaminants. |-- |Go to Step 25 |Go to Step 10 |
| |Refer to Alcohol/Contaminants-in-Fuel Test . | | | |
| |If a problem was found, repair as necessary. | | | |
| |Was a problem found? | | | |
|10 |Visually and physically inspect the PCM injector grounds, power |-- |Go to Step 25 |Go to Step 11 |
| |grounds and sensor grounds to ensure that they are clean, tight, and | | | |
| |in their proper locations. Refer to Ground Distribution in Electrical | | | |
| |Diagnosis. | | | |
| |If a problem is found, repair as necessary. Refer to Repair Procedures| | | |
| |in Electrical Diagnosis. | | | |
| |Was a problem found? | | | |
|11 |Visually and physically inspect the following areas for vacuum leaks: |-- |Go to Step 25 |Go to Step 12 |
| |Intake manifold. | | | |
| |EGR adapter. | | | |
| |EGR valve. | | | |
| |EGR feed pipes. | | | |
| |Injector O-rings. | | | |
| |If a problem is found, repair as necessary. | | | |
| |Was a problem found? | | | |
|12 |Remove the EGR valve. Refer to Exhaust Gas Recirculation Valve |-- |Go to Step 25 |Go to Step 13 |
| |Replacement . | | | |
| |Visually/physically inspect the valve to ensure that the pintle is not| | | |
| |sticking partially open. Also, inspect the EGR valve pintle and seat | | | |
| |for carbon deposits or burrs that may interfere with the pintle | | | |
| |sealing completely. | | | |
| |If a problem is found, repair as necessary. | | | |
| |Was a problem found? | | | |
|13 |Check for proper fuel injector operation. Refer to the Fuel Injector |-- |Go to Step 25 |Go to Step 14 |
| |Solenoid Coil Test . | | | |
| |If a problem is found, repair as necessary. | | | |
| |Was a problem found? | | | |
|14 |Visually and physically inspect the ignition wires associated with the|-- |Go to Step 25 |Go to Step 15 |
| |cylinder(s) which were misfiring to ensure that they are not damaged | | | |
| |and are connected to the proper cylinders at the coils and at the | | | |
| |spark plugs. | | | |
| |If a problem is found, repair as necessary. Refer to Secondary Wiring | | | |
| |in Ignition System. | | | |
| |Was a problem found? | | | |
|15 |Install a J 26792 spark tester at the spark plug end of the ignition |-- |Go to Step 20 |Go to Step 16 |
| |wire for the cylinder that is indicated by the Misfire Current Cyl # | | | |
| |counters or Misfire History Cyl # counters as having the most severe | | | |
| |misfire (largest number of counts). | | | |
| |Jumper the spark plug end of the companion cylinder ignition wire to | | | |
| |engine ground. | | | |
| |The companion cylinder is the cylinder that shares the same ignition | | | |
| |coil (i.e., 1/4; 2/5; 3/6). | | | |
| |Crank the engine while observing the spark tester. A crisp, blue spark| | | |
| |should be observed. | | | |
| |Is adequate spark present? | | | |
|16 |Remove and visually/physically inspect the ignition wires associated |-- |Go to Step 25 |Go to Step 17 |
| |with the cylinders that were indicated as misfiring. Ensure that the | | | |
| |wires and boots are free of carbon tracking and the insulation is not | | | |
| |damaged. | | | |
| |If a problem is found, replace malfunctioning ignition wire(s) as | | | |
| |necessary. Refer to Secondary Wiring in Ignition System. | | | |
| |WARNING | | | |
| | | | | |
| |Important: If carbon tracking or terminal discoloration is apparent at| | | |
| |the ignition coil end of any of the ignition wires, replace the | | | |
| |affected ignition wire and the associated ignition coil. Refer to | | | |
| |Ignition Control Module Replacement . | | | |
| | | | | |
| |Was a problem found? | | | |
|17 |Measure the resistance of the ignition wires associated with the |VIN 1 - 7K |Go to Step 25 |Go to Step 18 |
| |cylinders that were indicated as misfiring. |ohms (7,000 | | |
| |Replace any ignition wire(s) that measure greater than the specified |ohms) | | |
| |value. Refer to Secondary Wiring in Ignition System. |VIN K - 10K | | |
| |Was a problem found? |ohms (10,000 | | |
| | |ohms) | | |
|18 |Remove and visually/physically inspect the ignition coil(s) associated|-- |Go to Step 25 |Go to Step 19 |
| |with the cylinders that were indicated as misfiring. Ensure that the | | | |
| |coil(s) and coil towers are free of cracks and carbon tracking. | | | |
| |If a problem is found, replace damaged ignition coil(s) as necessary. | | | |
| |Refer to Ignition Control Module Replacement . | | | |
| |Was a problem found? | | | |
|19 |Measure the ignition coil secondary resistance. |5K-8K ohms |Go to Step 25 |Go to Step 24 |
| |If resistance is outside the specified values, replace the |(5000-8000 | | |
| |malfunctioning ignition coil(s) as necessary. Refer to Ignition |ohms) | | |
| |Control Module Replacement . | | | |
| |Was a problem found? | | | |
|20 |Remove the spark plugs from the cylinders that were indicated as |-- |Go to Engine |Go to Step 21 |
| |misfiring. Go to Spark Plugs in Ignition System. | |Misfire | |
| |Visually inspect the spark plug electrodes for excessive fouling. | |Mechanical | |
| |Refer to Spark Plugs in Ignition System. | |Diagnosis in | |
| |Was a problem found? | |Engine General | |
| | | |Information | |
|21 |Visually inspect spark plug insulators for cracks, carbon tracking, or|-- |Go to Step 25 |Go to Step 22 |
| |other damage. | | | |
| |Check the spark plug electrodes for incorrect gap. | | | |
| |If a problem is found, replace affected spark plug(s) as necessary. | | | |
| |Refer to Spark Plugs in Ignition System. | | | |
| |Was problem found? | | | |
|22 |Check for an engine mechanical problem. |-- |Go to Step 25 |Go to Step 23 |
| |Damaged accessory drive belt or pulley. | | | |
| |Damaged driven accessory (generator, water pump, drive belt tensioner,| | | |
| |ect). | | | |
| |Base engine mechanical problem. Refer to Engine Misfire Mechanical | | | |
| |Diagnosis in Engine General Information. | | | |
| |Loose or broken motor mount. | | | |
| |If a problem is found, repair as necessary. | | | |
| |Was a problem found? | | | |
|24 |Check for a transaxle TCC problem. Refer to Automatic Transaxle |-- |Go to Step 25 |Refer to |
| |Diagnosis . | | |Diagnostic Aids |
| |If a problem is found, repair the transaxle as necessary. Refer to | | | |
| |Automatic Transaxle Unit Repair . | | | |
| |Was a problem found? | | | |
|26 |Replace the ignition control module. Refer to Ignition Control Module |-- |Go to Step 25 |-- |
| |Replacement . | | | |
| |Is action complete? | | | |
|27 |Review and record Freeze Frame data |-- |Go to Step 2 |System OK |
| |Clear DTCs. | | | |
| |Start and idle the engine. | | | |
| |Operate the vehicle to duplicate the conditions present when the DTC | | | |
| |was set (as defined by the Freeze Frame data). | | | |
| |Monitor the scan tool Misfire Current Cyl # display for each cylinder.| | | |
| |Is Misfire Current Cyl # display incrementing for any cylinder | | | |
| |(indicating a misfire currently occurring)? | | | |
|Trouble Code: P0440 (3.8L V6 VIN K Auto) |Print this code data[pic] |
|EVAP System No Flow During Purge | |
Number of Trips to Set Code: 2
OBD II Monitor Type: CCM Details
Indicators: MIL Details
• EVAP Details
• MIL Details
Trouble Code Conditions:
DTC P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0125, P0443, P0449, P0452, P0453, P1106, P1107, P1112, P1114, P1115, P1121 and P1122 not set, engine started, system voltage over 10.0v, ECT and IAT sensors from 39-86ºF and within 16ºF at startup, vehicle driven at a steady speed of less than 75 mph, BARO more than 75 kPa, fuel level from 15-85%, and the PCM detected the EVAP system was unable to Achieva or maintain enough vacuum during the EVAP test.Note: An Ultrasonic Leak Detector can be used to help detect leaks in the EVAP system.
Possible Causes:
• Charcoal canister is loaded with fuel or moisture
• Fuel filler cap is loose, cross-threaded, damaged or wrong part
• Fuel tank, fuel filler neck or fuel sending unit 'O' ring is leaking
• Fuel tank pressure sensor is damaged, disconnected or it failed
• Fuel tank vapor line(s) is clogged, damaged or disconnected
• Purge valve vapor line is clogged, damaged, or disconnected
• Purge or vent solenoid power circuit is open (check the fuse)
• PCM has failed
|PATH: Diagnostics > Diagnostic Routines > Powertrain > Engine Controls - 3.8L > DTC P0440 Evaporative Emission |Print[pic] |
|(EVAP) System | |
DTC P0440 Evaporative Emission (EVAP) System
|NOTE |
|Applicable vehicles: |
|Bonneville, Eighty Eight, LeSabre (VIN C/H) |
DTC P0440 Evaporative Emission (EVAP) System
|[pic] |
| |
|Click to Enlarge |
Circuit Description
The evaporative system includes the following components:
• The fuel tank.
• The EVAP canister vent valve.
• The fuel tank pressure sensor.
• The fuel pipes and hoses.
• The fuel cap.
• The EVAP vapor lines.
• Ther EVAP purge lines.
• The evaporative emission canister.
• The EVAP purge valve.
The evaporative leak detection diagnostic strategy is based on applying vacuum to the EVAP system and monitoring vacuum decay. The PCM monitors vacuum level via the Fuel Tank Pressure sensor input. At an appropriate time, the EVAP purge valve and the EVAP canister vent valve are turned ON, allowing engine vacuum to draw a small vacuum on the entire evaporative emission system. If a sufficient vacuum level cannot be achieved, a large leak or a malfunctioning EVAP purge valve is indicated. This can be caused by the following conditions:
• Disconnected or malfunctioning fuel tank pressure sensor.
• Missing, loose or malfunctioning fuel cap.
• Disconnected, damaged, pinched, or blocked EVAP purge line.
• Disconnected or damaged EVAP canister vent hose.
• Disconnected, damaged, pinched, or blocked fuel tank vapor line.
• Disconnected or malfunctioning EVAP purge valve.
• Disconnected or malfunctioning EVAP canister vent valve.
• Open ignition feed circuit to the EVAP canister vent or purge valve.
• Damaged evaporative emissions canister.
• Leaking fuel sender assembly O-ring.
• Leaking fuel tank or fuel filler neck
Any of the above conditions can set DTC P0440.
Conditions For Setting the DTC
• No TP sensor, IAT sensor, or MAP sensor DTC(s) set.
• Start up engine coolant temperature is between 4° C and 30° C (40° F and 86° F).
• Start up engine coolant temperature is not more than 8° C (14° F) greater than start up intake air temperature.
• Start up intake air temperature is between 4° C and 30° C (40° F and 86° F).
• Start up intake air temperature is not more than 2° C (4° F) greater than start up engine coolant temperature.
• Fuel tank fuel level is between 15% and 85%.
• BARO is greater than 75 kPa.
• The EVAP system is not able to achieve or maintain vacuum during the diagnostic test.
Action Taken When the DTC Sets
• The PCM will illuminate the malfunction indicator lamp (MIL) during the first trip in which the diagnostic test has been run and failed.
• The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.
|WARNING |
|Important: Although these diagnostics are considered type A, they act like type B diagnostics under certain conditions. Whenever |
|the EVAP diagnostics report that the system has passed, or if the battery has been disconnected, the diagnostic must fail during |
|two consecutive cold start trips before setting a DTC. The initial failure is not reported to the diagnostic executive or displayed|
|on a scan tool. A passing system always reports to the diagnostic executive immediately. |
Conditions for Clearing the MIL/DTC
• The PCM will turn the MIL OFF when the diagnostic has been run and the malfunction condition is no longer present.
• A history DTC P0440 will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
• DTC P0440 can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed.
Diagnostic Aids
Check for the following conditions:
• Loose, missing, or leaking fuel cap.
• Cracked or punctured EVAP canister.
• Damaged or disconnected source vacuum line, EVAP purge line, vent hose or fuel tank vapor line.
• Poor connection at the PCM.
• Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
• Damaged harness. Inspect the wiring harness to the EVAP canister vent valve, the EVAP purge valve, and the fuel tank pressure sensor for an intermittent open or short circuit.
• Kinked, pinched or plugged vacuum source, EVAP purge, or fuel tank vapor line. Verify that the lines are not restricted.
• Malfunctioning or damaged canister.
• A malfunctioning canister may intermittenly allow charcoal into the EVAP purge solenoid and associated lines causing a DTC to be set. Use the following procedure to check for a carbon release condition:
• 1.
Turn OFF the ignition switch.
• 2.
Remove the EVAP purge valve. Refer to Evaporative Emission Canister Purge Solenoid .
• 3.
Lightly tap the EVAP purge valve and (if applicable) the vacuum switch on a clean work area looking for carbon particles exiting either of the vacuum ports.
• 4.
If no carbon release is evident, reinstall the components and continue with the DTC P0440 diagnostic table. If carbon is being released from either component, continue with this service procedure.
• 5.
Remove the charcoal canister from the vehicle.
• 6.
Ensure that the main cylinder valve is turned off on the J 41413 EVAP purge/pressure diagnostic station.
• 7.
Disconnect the black hose that connects the nitrogen cylinder to the EVAP purge/pressure diagnostic station at the pressure regulator by unscrewing the knurled nut on the regulator. No tools are required to remove the black hose from the regulator.
• 8.
Using a section of vacuum line, connect one end over the open threaded fitting of the EVAP purge/pressure diagnostic station pressure regulator.
• 9.
Connect the remaining end to the EVAP purge valve end of the EVAP purge line at the vehicle and turn on the main nitrogen cylinder valve. Continue to blow any debris from the purge line for 15 seconds.
• 10.
Return the EVAP Pressure/Purge Diagnostic Station to its original condition by re-installing the black hose that was disconnected in step 7.
• 11.
Replace the following components:
o The EVAP purge valve. Refer to Evaporative Emission Canister Purge Solenoid .
o The EVAP canister. Refer to Evaporative Emission Canister Replacement .
• 12.
Proceed with the DTC P0440 diagnostic table.
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
2. If a vent valve or EVAP purge valve electrical malfunction is present, the purge system will not operate correctly. Repairing the electrical malfunction will very likely correct the condition that set DTC P0440.
3. Checks the fuel tank pressure sensor at ambient pressure.
4. Determines whether or not the EVAP system can be sealed sufficiently to be pressurized. If not, the large leak must be located and corrected before continuing with diagnosis.
5. Verifies that the fuel tank pressure sensor accurately reacts to EVAP system pressure changes.
8. Checks for a blocked EVAP purge valve. The PCM commands the EVAP purge valve OFF (open) and the vent valve ON (closed) with the scan tool System Perf EVAP output control function activated. Any pressure in the system should be released through the EVAP purge valve within a few seconds when System Perf. is activated.
9. Ensures that sufficient source vacuum is present at the EVAP purge valve.
DTC P0440 - EVAP System
|Step |Action |Value(s) |Yes |No |
|1 |Was the Powertrain On-Board Diagnostic System Check performed? |-- |Go to Step 2 |Go to the Powertrain |
| | | | |On Board Diagnostic |
| | | | |(OBD) System Check |
|2 |WARNING |-- |Go to the other |Go to Step 3 |
| | | |DTC first | |
| |Important: Visually/physically inspect for the following | | | |
| |conditions: | | | |
| |Vacuum or purge lines disconnected. Refer to Emission Hose Routing| | | |
| |Diagram . | | | |
| |Loose or missing fuel cap. | | | |
| | | | | |
| |Is DTC P1655 Evaporative Emission (EVAP) Purge Solenoid Control | | | |
| |Circuit or DTC P1675 Evaporative Emission (EVAP) Vent Solenoid | | | |
| |Control Circuit also set? | | | |
|3 |Turn OFF the ignition switch. |0 in. H2O |Go to Step 4 |Go to Evaporative |
| |Remove the fuel cap. | | |Emission Control |
| |Turn ON the ignition switch. | | |System Diagnosis |
| |Observe Fuel Tank Pressure on the scan tool. | | | |
| |Is Fuel Tank Pressure at the specified value? | | | |
|4 |WARNING |5 in. H2O |Go to Step 5 |Go to Step 6 |
| | | | | |
| |Important:: Before continuing with diagnosis, zero the EVAP | | | |
| |Pressure and Vacuum (inches of H2O) gauges on the J 41413 EVAP | | | |
| |pressure/purge diagnostic station. | | | |
| | | | | |
| |Replace the fuel cap. | | | |
| |Capture Fail Record data for DTC P0440 and clear DTCs. | | | |
| |Using the scan tool, command the EVAP canister vent valve ON | | | |
| |(Closed). | | | |
| |Connect the J 41413 EVAP pressure/purge diagnostic station to the | | | |
| |EVAP service port. | | | |
| |Attempt to pressurize the EVAP system using the EVAP | | | |
| |pressure/purge diagnostic station (monitor pressure using the EVAP| | | |
| |pressure gauge on the EVAP pressure/purge diagnostic station). | | | |
| |Can specified value be achieved? | | | |
|5 |Maintain EVAP system pressure at 5 inches of H2O. |5 in. H2O |Go to Step 8 |Go to Step 7 |
| |Observe Fuel Tank Pressure on the scan tool. | | | |
| |Is Fuel Tank Pressure at the specified value? | | | |
|6 |Disconnect the fuel tank vapor line and the EVAP purge line from |5 in. Hg |Go to Step 11 |Go to Step 10 |
| |the EVAP canister. | | | |
| |Block the canister fitting for the fuel tank vapor line. | | | |
| |Connect a hand vacuum pump to the canister fitting for the EVAP | | | |
| |purge line. | | | |
| |Ensure that the EVAP canister vent valve is still commanded ON | | | |
| |(Closed). | | | |
| |Attempt to apply vacuum to the EVAP canister. | | | |
| |Can vacuum be maintained at the specified value? | | | |
|7 |Visually/physically check for the following conditions: |-- |Go to Step 16 |Go to Evaporative |
| |Restricted fuel tank vapor line. | | |Emission Control |
| |Restricted EVAP purge line. | | |System Diagnosis |
| |If a problem is found, repair as necessary. | | | |
| |Was a problem found? | | | |
|8 |Disconnect the vacuum source line at the EVAP purge valve and plug|5 in. H2O |Go to Step 9 |Go to Step 13 |
| |the vacuum source fitting on the solenoid. |0 in. H2O | | |
| |Using the scan tool output tests function, select System Perf. and| | | |
| |activate. | | | |
| |Pressurize the EVAP system to the first specified value (monitor | | | |
| |pressure using the EVAP pressure gauge on EVAP pressure/purge | | | |
| |diagnostic station). | | | |
| |Observe the EVAP pressure gauge on the EVAP pressure/purge | | | |
| |diagnostic station while removing the plug from the EVAP purge | | | |
| |valve vacuum source fitting. | | | |
| |Does the EVAP pressure decrease to the second specified value | | | |
| |within 15 seconds while System Perf. is activated? | | | |
|9 |Connect the in. Hg vacuum gauge on the EVAP pressure/purge |-15 in. Hg |Refer to |Go to Step 14 |
| |diagnostic station to the vacuum source line. | |Diagnostic Aids | |
| |Start the engine. | | | |
| |Run the engine above 2000 RPM and observe the source vacuum level.| | | |
| |Is the source vacuum level greater than the specified value? | | | |
|10 |Visually/physically check for the following conditions: |-- |Go to Step 16 |Go to Step 15 |
| |Vent hose disconnected or damaged. | | | |
| |EVAP canister damaged. | | | |
| |If a problem is found, repair as necessary. | | | |
| |Was a problem found? | | | |
|11 |Visually/physically check for the following conditions: |-- |Go to Step 16 |Go to Step 12 |
| |Missing or malfunctioning fuel cap. | | | |
| |Disconnected or leaking fuel tank vapor line. | | | |
| |Disconnected or damaged EVAP purge line. | | | |
| |If a problem is found, repair as necessary. | | | |
| |Was a problem found? | | | |
|12 |Using the scan tool, command the EVAP canister vent valve ON. |-- |Go to Step 16 |-- |
| |With the EVAP pressure/purge diagnostic station connected to the | | | |
| |EVAP service port, continuously attempt to pressurize the EVAP | | | |
| |system by leaving the EVAP pressure/purge diagnostic station | | | |
| |control knob in the pressurize position | | | |
| |Using the ultrasonic leak detector J 41416, locate and repair leak| | | |
| |in EVAP system. It may be necessary to partially lower the fuel | | | |
| |tank to examine the top tank connections. | | | |
| |Is action complete? | | | |
|13 |Replace the EVAP purge valve. Refer to Evaporative Emission |-- |Go to Step 16 |-- |
| |Canister Purge Solenoid . | | | |
| |WARNING | | | |
| | | | | |
| |Important: Check for carbon release into the EVAP system. Refer to| | | |
| |Diagnostic Aids. | | | |
| | | | | |
| |Is action complete? | | | |
|14 |Locate and repair cause of no source vacuum to the EVAP purge |-- |Go to Step 16 |-- |
| |valve. | | | |
| |WARNING | | | |
| | | | | |
| |Important: Check for carbon release into the EVAP system. Refer to| | | |
| |Diagnostic Aids. | | | |
| | | | | |
| |Is action complete? | | | |
|15 |Replace the EVAP canister vent valve. Refer to Evaporative |-- |Go to Step 16 |-- |
| |Emission Vent Valve Replacement . | | | |
| |Is action complete? | | | |
|16 |Turn ON the ignition switch. |15 in. H2O |Go to Step 3 |System OK |
| |Using the scan tool, command the EVAP canister vent valve ON |10 in. H2O | | |
| |(Closed). | | | |
| |Pressurize the EVAP system to the first specified value using the | | | |
| |EVAP pressure/purge diagnostic station (monitor pressure using the| | | |
| |gauge on the EVAP pressure/purge diagnostic station). | | | |
| |Switch the rotary switch on the EVAP pressure/purge diagnostic | | | |
| |station to HOLD and observe the EVAP pressure gauge. | | | |
| |Does the EVAP pressure decrease to less than the second specified | | | |
| |value within 2 minutes? | | | |
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