P0440
P0440-GENERAL EVAP SYSTEM FAILURE
Special Tools:
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Evaporative Purge Monitor tests the integrity of the hoses/tube between the throttle body/intake and the fuel tank. At key off, the Powertrain Control Module (PCM) monitors the Evaporative System Integrity Monitor (ESIM) Switch. As the fuel and air in the Fuel Tank cools, a vacuum will occur naturally inside the tank. One inch of vacuum will cause the switch to close. If the PCM sees the switch close before the counter reaches a calibrated amount, the monitor passes.
The monitor is a two stage test and runs only after the Evaporative system passes the small leak test. Stage one is non-intrusive. With the engine running, the monitor will first evaluate the delta pressure change of the Fuel Tank Pressure (FTP) Sensor while normal purge control is active. If the monitor does not pass within a calibrated amount of time, then an intrusive monitor will be enabled. The intrusive test runs only if stage one does not pass. This intrusive monitor will ramp in the purge flow to a target amount while evaluating the delta pressure in the entire system. If the delta pressure between purge off and purge on exceeds a calibrated amount, then the monitor will ramp out the purge flow and evaluate the delta pressure between the high flow and the new low flow target. If the delta pressure is less than a calibrated threshold then the monitor will pass.
- When Monitored:
Engine running after a cold start with the difference between ECT and AAT is less than 10°C (19°F). Fuel Level between 12% and 88% full. Manifold vacuum greater than a calculated minimum value. Ambient Temperature between 4°C and 35°C (40°F and 95°F).
- Set Condition:
When the monitor conditions are met, the Powertrain Control Module (PCM) will ramp in purge flow. If the PCM does not sense an ESIM Switch closure after a calculated amount of purge flow accumulation, an error is detected. Two Trip Fault. Three good trips to turn off the MIL.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
Diagnostic Test
1. VEHICLE HISTORY AND SERVICE BULLETIN INVESTIGATION
1. Ignition on, engine not running.
2. With the scan tool, select View DTCs. Record the related Freeze Frame data if any DTCs are present.
3. Whether or not any DTCs are active you will want to check the following items which may assist in repairing the customer's complaint successfully.
- Check the vehicle's repair history.
- If the vehicle has a repair history that pertains to the customer's current complaint, review the repair.
- Inspect the vehicle for any aftermarket accessories that may have been installed incorrectly.
- Check for any service bulletin(s) related to the customer's complaint or DTCs.
- If a service bulletin applies, follow the instructions per the service bulletin.
Choose the following scenario that applies:
The service bulletin repaired the customer's complaint.
- Testing complete.
A DTC is present, no service bulletins apply or the service bulletin didn't repair the customer's complaint.
- Go To 2
2. ACTIVE DTC
NOTE: Allow the vehicle to reach ambient temperature before continuing with this procedure.
NOTE: A loose gas cap could have caused this DTC to set. Make sure the gas cap is tight and in good condition.
NOTE: If the customer is experiencing an early fuel shut off during the fuel filling process along with P0440, P0441 and P0452 setting, check for restrictions in the Evaporative Purge tubes/hoses as well as the Fresh Air Filter before continuing.
1. Start the engine.
2. Allow the engine to reach normal operating temperature.
3. With the scan tool, select View DTCs.
NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.
Is the DTC Active or Pending at this time?
Yes
- Go To 3
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.
3. EVAPORATIVE SYSTEM INSPECTION
1. Turn the ignition off.
2. Perform a visual and physical inspection of the entire Evaporative Emission system.
3. Check for the following conditions:
- Improper installation of the Fuel Fill Cap
- Holes or cracks
- Loose seal points
- Evidence of damaged components
- Incorrect routing of hoses and tubes
- Loose or missing Fuel Filler Cap
- Damaged Locking tabs on Fuel Cap and/or fill tube
- Damaged seal points on Fuel Cap and/or fill tube
- Fuel cap gasket seal
Were any of the above conditions found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 4
4. EVAPORATIVE VACUUM SUPPLY HOSE INSPECTION
1. Carefully inspect the Evap Purge Solenoid vacuum supply hose for proper routing.
2. Check for a pinched or plugged hose from the throttle body or intake manifold to the Purge Solenoid.
3. Inspect the vacuum port at the throttle body or intake manifold for any damage or obstructions.
Were any problems found?
Yes
- Repair the vacuum supply, hose/tube as necessary. .
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 5
5. EVAP PURGE SOLENOID
NOTE: To continue testing you will need the Evaporative Emission Leak Detector (EELD) (8404B).
WARNING:
Keep lit cigarettes, sparks, flames, and other ignition sources away from the test area to prevent the ignition of explosive gases, Keep the test area well ventilated.
1. Connect the red power lead of the EELD to the battery positive terminal and the black ground lead to battery negative terminal.
2. Disconnect the vacuum hoses at the Evap Purge Solenoid.
3. Connect the SMOKE supply tip (black hose) to the "CAN" port on the Evap Purge Solenoid.
4. Set the smoke/air control switch to SMOKE.
5. While still holding the remote smoke/air start button, check to see if smoke is exiting the purge valve. This indicates that there is a leak internal to the purge valve.
NOTE: This is an optional method of checking the purge valve for leaks if the EELD is unavailable.
6. Disconnect the Smoke supply tip from the vacuum supply hoses at the Evap Purge Solenoid.
7. Using a hand vacuum pump, apply 10 in Hg to the "CAN" side of the Evap Purge Solenoid.
8. Observe the vacuum gauge for at least 15 seconds.
NOTE: The solenoid should hold vacuum for a minimum of 15 seconds.
Is smoke visible from the Evaporative Purge Solenoid or NOT hold a vacuum?
Yes
- Replace the Evap Purge Solenoid.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 6
6. ESIM SWITCH STATE
1. Turn the ignition off.
2. Connect the previously disconnected vacuum hose.
3. Disconnect the ESIM Switch harness connector.
4. Ignition on, engine not running.
5. Monitor the ESIM Switch state on the scan tool.
6. Carefully connect a jumper wire between the ESIM Signal circuit and the Ground circuit in the ESIM Switch harness connector.
7. Monitor the ESIM Switch state on the scan tool.
Did the Switch change from OPEN to CLOSED when the jumper wire was installed?
Yes
- Go To 9
No
- Go To 7
NOTE: Remove the jumper wire before continuing.
7. EXCESSIVE RESISTANCE IN THE (K108) ESIM SIGNAL CIRCUIT
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Measure the resistance of the (K108) ESIM Signal circuit from the ESIM harness connector to the PCM C1 harness connector.
Is the resistance below 5.0 Ohms?
Yes
- Go To 8
No
- Repair the ESIM Signal circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
8. EXCESSIVE RESISTANCE IN THE (Z939) GROUND CIRCUIT
1. Using a 12-volt test light connected to B+, probe the (Z939) Ground circuit at the ESIM harness connector.
NOTE: The test light should illuminate brightly. Compare the brightness to that of a direct connection to B- (ground).
Does the test light illuminate brightly?
Yes
- Go To 14
No
- Repair the (Z939) Ground circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
9. VERIFY EVAPORATIVE EMISSION LEAK
WARNING:
Keep lit cigarettes, sparks, flames, and other ignition sources away from the test area to prevent the ignition of explosive gases. Keep the test area well ventilated. Failure to do so may result in possible serious or fatal injury.
1. Turn the ignition off.
2. To continue testing you will need Evaporative Emission Leak Detector (EELD). (8404B)
NOTE: The fuel tank should have between 20% and 80% of fuel tank capacity to properly test the Evaporative system.
3. Connect the red power lead of EELD to the battery positive terminal and the black ground lead to battery negative terminal.
4. Block the vent hose of the Evaporative Canister.
5. Connect shop air to the EELD.
6. Set the smoke/air control switch to AIR.
7. Insert the tester's AIR supply tip (clear hose) into the.040 orifice on the tester's control panel.
8. Press the remote smoke/air start button.
9. Position the red flag on the air flow meter so it is aligned with the indicator ball.
10. When the calibration is complete, release the remote button. The EELD flow meter is now calibrated in liters per minute.
11. Install the service port adapter (8404-14) on the vehicle's service port (if equipped) or install the adapter (8404-ADP) into the filter line.
12. Connect the Air supply hose from the EELD to the service port (if equipped) or to the adapter. (8404-ADP)
13. Press the remote button to activate AIR flow.
14. Compare the flow meter indicator ball reading to the red flag.
15. ABOVE the red flag indicates a leak present.
16. BELOW the red flag indicates a sealed system.
Is the indicator ball above the red flag?
Yes
- Go To 10
No
- Go To 12
10. EVAPORATIVE EMISSION LEAK DETECTION
NOTE: A thorough visual inspection of the Evaporative system hoses, tubes and connections may save time in your diagnosis. Look for any physical damage or signs of wetness at connections. The strong smell of fuel vapors may aid diagnosis also.
1. Remove the Air supply hose from the service port or the adapter. (8404-ADP)
2. Connect the SMOKE supply tip (black hose) to the service port (if equipped) or to the adapter. (8404-ADP)
3. Set the smoke/air control switch to SMOKE.
NOTE: The flow meter indicator ball will not move at this point.
4. Press the remote smoke/air start button.
NOTE: Make sure that smoke has filled the Evaporative system by continuing to press the remote smoke/air start button, remove the vehicle fuel cap and wait for the smoke to exit. Once smoke is indicated reinstall the fuel cap.
NOTE: For optimal performance, introduce smoke into the system for an additional 60 seconds; continue introducing smoke at 15 second intervals, as necessary.
5. While still holding the remote smoke/air start button, use the white light (8404-CLL) to follow the Evaporative system path and look for the source of the leak indicated by exiting smoke.
6. If a leak is concealed from view (i.e., top of fuel tank), release the remote smoke/air start button and use the ultraviolet (UV) black light (8404-UVL) and the yellow goggles (8404-20) to look for residual traces of dye that are left behind by the smoke.
7. The exiting smoke deposits a residual fluid that is either bright green or bright yellow in color when viewed with a UV light.
NOTE: The Evaporative System is divided into three zones. A leak from any of these zones can cause this DTC to set. The lists below specify the possible leak points in that specific zone. For further assistance see the Zone Identification Charts below.
8.
9.
10.
NOTE: Carefully inspect the vent side of the Evaporative Canister. Due to the filtering system in the canister the smoke or dye may or may not be visible. Introducing smoke into the filtered side of the canister may assist in locating the leak.
Select the appropriate response from the list below:
A leak was found at the gas cap or fuel filler tube.
- Go To 11
A leak was found in one or more of the Evaporative System zones.
- If the leak is at a hose connection, remove the hose then reconnect the hose and check for a leak again. All other leaks, repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No leaks were detected.
- Go To 12
11. LEAK AT GAS CAP
1. Remove the SMOKE supply tip (black hose) from the service port (if equipped) or to the adapter. (8404-ADP)
2. Install Leak Check Adapter (8382) (1/4 turn cap) or Fuel Tank Adapter (6922) (screw on cap) and Leak Check Adapter (8399) (secondary seal depressor) and repeat step 10.
NOTE: The gas cap adapter is being used as a known good cap.
Was a leak found at the gas cap adapter?
Yes
- Replace the Fuel Filler tube assembly.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Replace the gas cap.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
12. EVAPORATIVE PURGE HOSE/TUBE AND FRESH AIR FILTER OBSTRUCTION
1. Inspect the Evaporative Purge hose/tube for proper routing and installation between the Evap Purge Solenoid and the Fuel Tank between the Fuel Tank and the Evap Purge Canister
2. Make sure the hose/tube and fresh air filter are not damaged, kinked and free from any obstructions.
Were any problems found?
Yes
- Repair or replace as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 13
13. EVAPORATIVE SYSTEM INTEGRITY MONITOR SWITCH
1. Use the wiring diagram/schematic as a guide, inspect the wiring and connections between the ESIM Switch and the PCM.
- Look for any chafed, pierced, pinched or partially broken wires.
- Look for any broken, bent, pushed out or corroded terminals.
- Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the ESIM Switch and the Powertrain Control Module connectors.
- Perform any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair and Replace as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Replace the ESIM Switch.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
14. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Evap Purge Solenoid Assembly, Evaporative System Integrity Monitor (ESIM) Switch and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals.
4. Monitor the scan tool data relative to these circuits and wiggle test the wiring and connectors.
5. Look for the data to change or for the DTC to reset during the wiggle test.
6. Perform any Technical Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Replace and program the Powertrain Control Module. .
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.