DTC P043E (2020 2021)
DTC P043E: Evaporative Emission (EVAP) Leak Check Module Standard Pressure Low
General Description
The powertrain control module (PCM) starts the evaporative emission (EVAP) system diagnosis after the vehicle has been turned to the OFF (LOCK) mode, and has met all other enable conditions (initial engine coolant temperature [ECT Sensor 1] and off for at least 5 hours). The EVAP system diagnosis is performed by reducing pressure between the EVAP canister and the atmosphere. If pressure is reduced with the fuel vapor containment valve open, the entire EVAP system will be monitored, and if the fuel vapor containment valve is closed, only the EVAP canister side will be monitored.
A malfunction is detected and a DTC is stored when changes in the pressure are equal to or less than the prescribed value after the prescribed time of starting the system pressure reduction.
EVAP leak check module operation flow
- Reference pressure measurement : Malfunction check in the EVAP leak check module and determination of early completion of pressure reduction when normal.
- System pressure reduction : Pressure in the EVAP system is reduced to measure the ultimate pressure.
- Reference pressure re-measurement : Leak is detected by comparing with the ultimate pressure of the system pressure reduction.
- Reference value is to be measured twice considering change in the characteristics of the vacuum pump during detection.
Reference pressure is the pressure reduction by the reference orifice (#40 equivalent) in the EVAP leak check module used to check for leak by comparison with the system pressure reduction.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Once per driving cycle |
| Sequence | None |
| Duration | At least 6 minutes, 45 seconds but not more than 22 minutes, 37 seconds |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Elapsed time after turn the vehicle to the ON mode | 10 minutes | - |
| Elapsed time after turn the vehicle to the OFF (LOCK) mode | 5 hours | - |
| PCM wake up engine coolant temperature [ECT Sensor 1] | 40 deg.F (5 deg.C) | 95 deg.F (35 deg.C) |
| Barometric pressure [Baro Sensor] | 76 kPa (569 mmHg, 22.5 inHg) | - |
| 12 volt battery voltage | 10.5 V | - |
| Other | No refueling is required | |
[ ]: HDS Parameter
Malfunction Threshold
The reference pressure is -5 kPa (-1.5 inHg, -38.1 mmHg) or less.
Possible Cause
- Vacuum pump failure
- Vacuum pump (Motor) failure
- Control valve failure
- Reference orifice flow quantity is excessive
- Reference orifice flow quantity is too low
Confirmation Procedure
Operating Condition
- With the engine coolant temperature [ECT Sensor 1] within the specified range, turn the vehicle to the ON mode, and wait for at least 10 minutes.
- Turn the vehicle to the OFF (LOCK) mode, and wait for at least 5 hours.
- After the PCM wakes up and wait at least 22 minutes, 37 seconds.
With the HDS
Do the EVAP TEST in the INSPECTION MENU with the HDS.
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 are 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 are within the specified temperature range, the MIL comes on and a Confirmed DTC and the freeze data 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 or by disconnecting the 12 volt battery.