This DTC tests the evaporative emission (EVAP) system for a small leak. The control module monitors the fuel tank pressure (FTP) sensor signal to determine the vacuum decay rate. At an appropriate time, the control module turns the EVAP canister purge solenoid valve ON and the EVAP canister vent solenoid valve ON. This allows the engine to draw a vacuum on the EVAP system. At a calibrated time, or vacuum level, the control module turns the EVAP canister purge solenoid valve OFF, sealing the system, and monitors the FTP sensor input in order to determine the EVAP system vacuum decay. If the control module detects a leak larger than a calibrated amount, this DTC sets.
The following table illustrates the relationship between the ON and OFF states, and the Open or Closed states of the EVAP canister purge and vent solenoid valves.
Control Module Command | EVAP Canister Purge Solenoid Valve | EVAP Canister Vent Solenoid Valve |
---|---|---|
ON | Open | Closed |
OFF | Closed | Open |
• | DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0125, P0128, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P0502, P0503, P0721, P0722, P1106, P1107, P2119, P2135, P2610 are not set. |
• | The ignition voltage is between 10-18 volts. |
• | The barometric pressure (BARO) is more than 74 kPa. |
• | The fuel level is between 15-80 percent. |
• | The engine coolant temperature (ECT) is less than 4°C (39°F). |
• | The intake air temperature (IAT) is between 4-30°C (39-86°F). |
• | The start up ECT and IAT are within 9°C (16°F) of each other. |
• | The vehicle speed sensor (VSS) is less than 121 km/h (75 mph). |
• | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
• | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records. |
• | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
• | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
• | Clear the MIL and the DTC with a scan tool. |
• | To help locate intermittent leaks, use the J 41413-200 Evaporative Emissions System Tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT High Intensity White Light. |
• | To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT . |
• | For intermittent conditions, refer to Intermittent Conditions . |
The numbers below refer to the step numbers on the diagnostic table.
Introducing smoke in 15 second intervals may allow smaller leak areas to be more noticeable. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner.
This step verifies that repairs are complete.
Step | Action | Yes | No | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Evaporative Emissions Hose Routing Diagram Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | |||||||||||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | |||||||||||
2 |
Did you find and correct the condition? | Go to Step 5 | Go to Step 3 | ||||||||||
Important: Ensure that the vehicle underbody temperature is similar to the ambient temperature and allow the surrounding air to stabilize before starting the diagnostic procedure. System flow will be less with higher temperatures.
Did you locate and repair a leak source? | Go to Step 5 | Go to Step 4 | |||||||||||
4 |
Did you locate and repair a leak source? | Go to Step 5 | Go to Diagnostic Aids | ||||||||||
Important: Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize.
Is the floating indicator below the red flag? | Go to Step 6 | Go to Step 2 | |||||||||||
6 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK |