DTC P0497
DTC P0497: Evaporative Emission (EVAP) System Low Purge Flow Detected
General Description
Negative pressure is created in the evaporative emission (EVAP) system by reducing the pressure in the EVAP leak detection module. When the EVAP canister purge valve is opened under that state, the air is sucked in through the intake manifold to cause the EVAP system pressure to be recovered to barometric pressure. The powertrain control module (PCM) detects a malfunction in the IAT sensor 1 and stores a DTC when the prescribed change in the pressure toward positive pressure has not occurred after a given period of time of opening the EVAP canister purge valve.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Once per driving cycle |
| Sequence | None |
| Duration | 22 minutes, 17 seconds or more |
| DTC Type | Two drive cycles, MIL on |
Enable Conditions
| Condition | Minimum | Maximum |
|---|---|---|
| Elapsed time after turn the vehicle to the ON mode | 10 seconds | - |
| 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 (22.5 inHg, 569 mmHg) | - |
| 12 volt battery voltage | 10.5 V | - |
| Other | No refueling is required | |
[ ]: HDS parameter
Malfunction Threshold
When the change in the pressure is 0.4 kPa (0.11 inHg, 3 mmHg) or less toward positive pressure continuously for 22 minutes, 17 seconds or more after opening the EVAP canister purge valve.
Possible Cause
- EVAP canister purge valve passage clogged
- EVAP canister purge valve passage stuck
- EVAP leak check module passage clogged
- EVAP canister internal clogged
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 22 minutes, 17 seconds.
With the HDS
Do the EVAP FUNCTION 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, 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.