DTC P043F
DTC P043F : Evaporative Emission (EVAP) Leak Check Module Standard Pressure High
General Description
The powertrain control module (PCM) starts the evaporative emission (EVAP) system diagnosis after the vehicle has been driven with certain condition and turned to the OFF (LOCK) mode with all other enable conditions (engine coolant temperature, vehicle soak duration, etc.) are met. The EVAP system diagnosis is performed by reducing pressure with the EVAP leak check module vacuum pump that is equipped between the EVAP canister and atmosphere.
EVAP leak check module operation flow
- Reference pressure measurement : Checks the status of the EVAP leak check module or determines the diagnosis termination if the system is OK.
- System pressure reduction : Reduces pressure in the EVAP system and measures the ultimate pressure.
- Reference pressure re-measurement : Determines the leak of the system by comparing the ultimate pressure of the system pressure reduction with the reference pressure re-measurement.
- Reference value is to be measured twice considering change in the characteristics of the vacuum pump during detection. The re-measrement is done twice considering the change in the characteristics of the EVAP leak check module vacuum pump during detection.
Reference pressure is a pressure reduced by the reference orifice (#40 equivalent) in the EVAP leak check module, and used to check for leak by comparing with the system reduction pressure.
If the measured reference pressure is a specified value, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Once per driving cycle |
| Sequence | None |
| Duration | At least 6 minutes 30 seconds, but not more than 18 minutes 45 seconds |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
Common Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Barometric pressure [ Baro Sensor ] | 76 kPa (569 mmHg, 22.5 inHg) | - |
| 12 volt battery voltage [ Battery ] | 10.5 V | - |
| Other | No refueling during the driving cycle | |
| [ ] : HDS Parameter | ||
Conditions before soak
| Condition | |
|---|---|
| Other | Driven for certain minutes |
Conditions during soak
| Condition | Minimum | Maximum |
|---|---|---|
| Soak duration | 5 hours | - |
Malfunction Threshold
The reference pressure is -0.1 kPa (-7.5 mmHg, -0.3 inHg) or more.
Possible Cause
The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
- EVAP leak check module vacuum pump failure
- Canister change over valve failure
- Reference orifice flow quantity excessive
- Reference orifice flow quantity low
Confirmation Procedure
Operating Condition
- Drive the vehicle for a while.
- Turn the vehicle to the OFF (LOCK) mode and wait for at least 5 hours 19 minutes.
- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle with the engine coolant temperature and intake air temperature at engine start-up within the specified temperature range, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle with the engine coolant temperature and intake air temperature at engine start-up within the specified temperature range, the MIL comes on and a Confirmed DTC, the freeze data, and the on-board snapshot are stored.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.