Advanced Diagnostics

DTC P0457: Evaporative Emission (EVAP) System Leak Detected/Fuel Cap Loose or Missing




General Description
There are two conditions when the evaporative emission (EVAP) system will not hold vacuum sufficiently, and the pressure in the fuel tank doesn't become negative.

1. EVAP system low purge flow.
2. EVAP system leakage or the fuel fill cap is loose/off.

Here is a description of condition 2:

The engine control module (ECM)/powertrain control module (PCM) monitors the fuel tank pressure (FTP) sensor output. If the FTP sensor output does not indicate the specified vacuum when applying vacuum when the fuel vapor density is high, the ECM/PCM detects a large leak (fuel fill cap loose/off) and a DTC is stored. [The malfunction detection is performed during EVAP system leak detection (P0455, P0456).]




Monitor Execution, Sequence, Duration, DTC Type, OBD Status




Enable Conditions

Malfunction Threshold
- The output from the fuel tank pressure sensor is -0.2 kPa (-0.07 in.Hg, -2 mmHg) or more for at least 45 seconds.
- Fuel vapor density during compression is at least 0.1 g (0.004 oz) for up to 45 seconds.

Confirmation Procedure with the HDS
Do the EVAP FUNCTION TEST in the INSPECTION MENU with the HDS.

Driving Pattern
1. After the vehicle has been left for an appropriate amount of time as specified, with the engine coolant temperature and intake air temperature within the specified range, start the engine.
2. Warm up the engine at idle until the radiator fan comes on.
3. Drive the vehicle immediately at a speed between 45 - 75 mph (72 - 120 km/h) for at least 20 minutes.
4. After stopping the engine, turn the ignition switch off, and leave the vehicle for 32 minutes or more (EONV executes).

- Drive the vehicle in this manner only if the traffic regulations and ambient conditions allow.

Diagnosis Details

Conditions for illuminating the fuel fill cap caution
When a malfunction is detected during the first drive cycle with the ECT at engine start-up within the specified temperature range, a Temporary DTC is stored in the ECM/PCM memory. If the malfunction recurs during the next (second) drive cycle with the ECT at engine start-up within the specified temperature, the caution is indicated. If the malfunction recurs during the next (third) drive cycle with the ECT at engine start-up within the specified temperature range, the MIL comes on and the DTC and the freeze frame data are stored. The caution is cleared when the MIL comes on.

Conditions for clearing the fuel fill cap caution
The caution will be cleared if the malfunction does not recur during the EVAP system leakage diagnostic. The caution can be cleared by using the scan tool Clear command or by disconnecting the battery.