DTC Advanced Diagnostics: P24C1 (1.5 L Engine)

DTC Advanced Diagnostics: P24C1

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, 40 seconds but not more than 18 minutes, 55 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 (569 mmHg, 22.5 inHg)	–
Battery voltage [BATTERY]	10.5 V	–

[ ]: HDS Parameter

Malfunction Threshold

When the change in the pressure 6 minutes, 40 seconds after starting the system pressure reduction is 0.3 kPa (2.3 mmHg, 0.09 inHg) or less.

Possible Cause

	Vacuum pump failure
	Vacuum pump (Motor) failure
	Control valve failure
	Reference orifice flow quantity is excessive

Confirmation Procedure

Operating Condition

1.	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.
2.	Turn the vehicle to the OFF (LOCK) mode, and wait for at least 5 hours.
3.	PCM wake up, and wait at least 18 minutes, 55 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.