Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P043E: Evaporative Emission (EVAP) System Reference Orifice Flow InsufficientDTC P043F: Evaporative Emission (EVAP) System Reference Orifice Flow Excessive
Diagnostic Fault Information
Component | Cause | DTCs | ||||
|---|---|---|---|---|---|---|
EVAP Vent Solenoid Valve | Always ON | P043E, P043F, P2401, P2402, P2419 | ||||
EVAP Vacuum Leak Pump |
| P043E, P043F, P2401, P2402, P2419 | ||||
EVAP Canister Assembly | 0.02 Inch Reference Orifice Blocked or Restricted | P043E, P043F, P2401, P2402, P2419 | ||||
0.02 Inch Reference Orifice High Flow | P043E, P043F |
Circuit/System Description
The diagnostic strategy for the evaporative emission (EVAP) system uses a vacuum pump to test for system leaks, after the engine is OFF. A unique fuel tank, EVAP canister, and EVAP vacuum leak pump work together to provide enhanced system diagnosis. The vacuum leak pump, the fuel tank pressure (FTP) sensor and the EVAP canister vent valve are all integral parts of one assembly. The assembly is attached directly to the EVAP canister, located near the fuel tank.
After the vehicle has sat with the engine OFF for greater than 5 hours and the engine coolant temperature is less than 35°C (95°F), a comprehensive diagnostic is enabled. The complete diagnostic test can take up to 15 minutes to run, with leak detection comprising the largest portion of the test.
The following table illustrates the relationship between the ON and OFF states, and the OPEN or CLOSED states of the EVAP canister purge and vent valves.
Control Module Command | EVAP Canister Purge Valve | EVAP Canister Vent Valve |
|---|---|---|
ON | Open | Closed |
OFF | Closed | Open |
Conditions for Running the DTC
| • | DTC P0110, P0112, P0113, P0115, P0117, P0118, P0450, P0451, P0452, P0453, P2610 are not set. |
| • | Five, seven, or nine and one half hours have elapsed after the engine was turned OFF. |
| • | Atmospheric pressure is between 70-110 kPa. |
| • | Battery voltage is greater than 10.5 volts. |
| • | Engine coolant temperature is between 4-35°C (40-95°F). |
| • | Intake air temperature is between 4-35°C (40-95°F). |
| • | The ignition remains OFF for the duration of the test. |
| • | The DTCs run once per drive cycle when the above conditions are met. |
Conditions for Setting the DTC
P043E
The powertrain control module (PCM) has determined the reference orifice of the EVAP vacuum leak detection pump is blocked or restricted.
P043F
The PCM has determined there is too much flow through the reference orifice of the EVAP vacuum leak detection pump.
Action Taken When the DTC Sets
DTC P043E and P043F are Type B DTCs.
Conditions for Clearing the DTC
DTC P043E and P043F are Type B DTCs.
Diagnostic Aids
Low fuel levels in the fuel tank can affect the accuracy of the Service Bay Test. Fill the fuel tank to between one half and three quarters and retest.
Reference Information
Schematic Reference
Evaporative Emissions Hose Routing Diagram
Description and Operation
Evaporative Emission Control System Description
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
With Service Bay Test
- Verify the EVAP system using the EVAP Service Bay Test, refer to Service Bay Test. DTC P043E or P043F should not set.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Without Service Bay Test
- Verify the EVAP system components and hoses are correctly routed and securely connected.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
- Observe the DTC information with a scan tool. Verify that DTC P2401, P2402, or P2419 are not set.
- Test for a blockage or restriction in the EVAP air filter and vent inlet hoses.
| ⇒ | If the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle. |
| ⇒ | If the filter and passages test normal, replace the EVAP vacuum pump assembly. |
Repair Instructions
Repair Verification
With Service Bay Test
Verify the EVAP system repair using the EVAP Service Bay Test.
Without Service Bay Test
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
