DTC P24C1 (2018 2019)
DTC P24C1: Canister Change Over Valve Stuck Close
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 diagnosed, and if the fuel vapor containment valve is closed, only the EVAP canister side will be diagnosed.
A malfunction is detected and a DTC is stored when the max and min values of the pressure measurements within the prescribed time during reference pressure measurement is equal to or more than the prescribed value.
EVAP leak detection module operation flow
- Reference pressure measurement : Malfunction detection 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.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Once per driving cycle |
| Sequence | None |
| Duration | At least 6 minutes, 55 seconds but not more than 19 minutes, 22 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 | - |
| Barometric pressure [Baro Sensor] |
76 kPa (22.5 inHg, 569 mmHg) | - |
| Battery voltage [Battery] |
10.5 V | - |
[ ]: HDS Parameter
Malfunction Threshold
When the change in the pressure 6 minutes, 55 seconds after starting the system pressure reduction is 0.3 kPa (0.09 inHg, 2.3 mmHg) or less.
Possible Cause
- Vacuum pump failure
- Vacuum pump (Motor) failure
- Control valve failure
- Reference orifice flow quantity is excessive
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.
- PCM wake up, and wait at least 19 minutes, 22 seconds.
With the HDS
Select the EVAP TEST in the INSPECTION MENU, then select the FUNCTION TEST with the HDS.
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, 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, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.