P0457
DTC P0457 EVAPORATIVE EMISSION CONTROL SYSTEM LEAK DETECTED (FUEL CAP LOOSE/OFF)1. OUTLINE OF DIAGNOSIS
Check if there is a leakage in fuel system or not, and perform the function diagnosis of valve.
In this system diagnosis, check for leakage and valve function is conducted by changing the fuel tank pressure and monitoring the pressure change using the fuel tank pressure sensor. When in 0.04 inch diagnosis, perform in the order of mode Z -> mode A -> mode B -> mode C and mode D; When in 0.02 inch diagnosis, perform in the order of mode A -> mode B -> mode C -> mode D and mode E.
0.04-inch Diagnosis
Mode Table for Evaporative Emission Control System Diagnosis
0.02-inch Diagnosis
2. COMPONENT DESCRIPTION
Drain valve controls the ambient air to be introduced to the canister.
3. ENABLE CONDITION
0.04-inch Diagnosis
0.02-inch Diagnosis
4. GENERAL DRIVING CYCLE
0.04-inch Diagnosis
- Perform the diagnosis only once, 335 seconds or more after starting the engine, at a constant speed of 72 km/h (45 MPH) or more.
- Pay attention to the fuel temperature and fuel level.
0.02-inch Diagnosis
- Perform the diagnosis after 125 seconds or more have elapsed at a constant engine speed of 50 km/h (31 MPH) or higher to judge as NG or OK.
- If judgment cannot be made, repeat the diagnosis.
- Pay attention to the fuel level.
5. DIAGNOSTIC METHOD
Purge control solenoid valve stuck open fault diagnosis
DTC
P0457 Evaporative Emission Control System Leak Detected (Fuel Cap Loose/Off)
Purpose of Mode Z
When performing the leakage diagnosis of EVAP system, the purge control solenoid valve must operate normally. Therefore, mode Z is used to diagnose the purge control solenoid valve stuck open condition. Note that if a purge control solenoid valve stuck open fault is detected, the EVAP system leakage diagnosis is cancelled.
Diagnostic method
Purge control solenoid valve functional diagnosis is performed by monitoring the tank pressure in mode Z.
Abnormality Judgment
If OK judgment cannot be made, extend Mode Z, and Judge as NG when the following conditions are established after predetermined amount of time.
Time Needed for Diagnosis: 5000 ms + 3000 ms + 13000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.
When judgment for purge control solenoid valve stuck open NG is made, end the evaporative diagnosis. Cancel the evaporative diagnosis when the OK/NG judgment for purge control solenoid valve stuck open cannot be made in Mode Z.
Normality Judgment
Judge as OK and change to Mode A when the following conditions are established after 3000 ms has passed since Mode Z started.
Normal
evptez - evptezha ≤ 0.4 kPa (3 mmHg, 0.1 inHg) Normal when above is established
Time Needed for Diagnosis: 5000 ms + 3000 ms
Purge control solenoid valve Open Fixation
- evptezini ≤ 0.4 kPa (2.9 mmHg, 0.1 inHg)
- evptez - evptezha > 0.9 kPa (6.5 mmHg, 0.3 inHg)
- No fuel sloshing equal to or over the value of Map 6 for 40000 ms or more Judge as abnormal when all are established.
Leak Diagnosis
DTC
P0442 Evaporative Emission Control System Leak Detected (Small Leak)
P0457 Evaporative Emission Control System Leak Detected (Fuel Cap Loose/Off)
- The diagnostic consists of creating a sealed vacuum in the fuel tank and then determining the presence of leakage from the speed at which the tank internal pressure returns to barometric pressure.
- The diagnosis is divided into the following five phases.
Mode A: (Estimated evaporation gas amount)
Calculate the tank pressure change amount (P1) when using mode A. After calculating P1, switch to mode B.
Mode B: (Negative pressure sealed)
Introduce negative pressure in the intake manifold to the tank.
Approx. 0 -> -1.4 kPa (0 -> -10.5 mmHg, 0 -> -0.4 inHg)
When the pressure above (desired negative pressure) is reached, enters Mode C.
In this case, if the tank pressure does not reach the target negative pressure, judge that there is a large leakage in the system and terminate the evaporative emission control system diagnosis.
Abnormality Judgment
Judge as NG (large leakage) when the following conditions are established.
Time Needed for Diagnosis: 5000 ms + 3000 ms + 10000 ms + 10000 ms + 25000 ms
Mode C: (Check pressure rise)
Stop the introduction of negative pressure. (Wait until the tank pressure returns to the start level of P2 calculation.)
Change to Mode D when the tank pressure returns to the start level of P2 calculation.
Judge immediate OK and change to Mode E when it does not return in spite of spending the specified time.
Time Needed for Diagnosis: 5000 ms + 3000 ms + 10000 ms + 10000 ms + 25000 ms + 14013 ms
Mode D: (Measure amount of negative pressure change)
Monitor the tank pressure change amount when using mode D. In this case, the tank pressure increases, (nears barometric pressure) because evaporation occurs. However, if any leakage exists, the pressure increases additionally in proportion to this leakage. The pressure variation of this tank is P2.
After calculating P2, perform a small leak diagnosis according to the items below.
When Mode D is ended
Assign tank variations measured in Mode A and Mode D, P1 and P2, to the formula below, judge small leaks in the system. If the measured judgment value exceeds the threshold value, it is judged to be a malfunction.
Abnormality Judgment
Judge as NG when the following conditions are established within the predetermined time. Judge as OK and clear the NG if the following conditions are not established within the predetermined time.
Time Needed for Diagnosis: 5000 ms + 3000 ms + 10000 ms + 10000 ms + 25000 ms + 14013 ms + 10000 ms
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.
Leak Diagnosis
DTC
P0456 Evaporative Emission Control System Leak Detected (very small leak)
- The diagnostic consists of creating a sealed vacuum in the fuel tank and then determining the presence of leakage from the speed at which the tank internal pressure returns to barometric pressure.
- The diagnosis is divided into the following five phases.
Mode A: (0 point compensation)
When the pressure in the tank is not near 0 mmHg, wait until it returns to 0 point (near 0 mmHg). Shift to mode B when returned to the 0 point. Cancel the diagnosis when 0 point does not return in the specified time.
Mode B: (Negative pressure introduced)
Introduce negative pressure in the intake manifold to the tank.
Approx. 0 -> -2 kPa (0 -> -15 mmHg, 0 -> -0.6 inHg)
When the pressure above (desired negative pressure) is reached, enters Mode C.
When the tank internal pressure does not reach the target negative pressure, the diagnosis is cancelled.
Mode C: (Negative pressure maintained)
Stop the introduction of negative pressure. (Wait until the tank pressure returns to the start level of P2 calculation.)
Change to Mode D either when the tank pressure returns to the start level of P2 calculation, or when the predetermined amount of time has passed.
Mode D: (Calculate the amount of negative pressure change)
Monitor the tank pressure in mode D, calculate the pressure change in the tank (P2), and measure the time (evpdset) for the tank pressure to change to the Mode E shifting pressure. When the Mode E shifting pressure is reached, Mode E is entered. If it does not change to the Mode E shifting pressure after the predetermined amount of time has passed, make advanced OK judgment or cancel the diagnosis according to the value of P2.
Normality Judgment
Judge as OK when the following conditions are established.
Mode E: (Evaporation occurrence amount calculation)
Calculate the change of tank pressure with the time evpdset (P1) to judge as NG/OK according to the value of P1. (ambiguous determination acceptable).
Abnormality Judgment
Judge as NG when the following conditions are established.
Time Needed for Diagnosis: Value of Map 1 + Value of Map 2 + Value of Map 3 + 0 ms + Value of Map 4 + 0 ms + Value of Map 4 + Value of Map 5
Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.
Normality Judgment
Judge as OK when the following conditions are established.
Time Needed for Diagnosis: Value of Map 1 + Value of Map 2 + Value of Map 3 + 0 ms + Value of Map 4 + 0 ms + Value of Map 4 + Value of Map 5