EVAP Basic Inspection

HINT:

• Read freeze frame data using hand-held or OBD II scan tool. Freeze frame data records engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
• Check for pending DTCs. On the hand-held tester, enter the following menus:

  DIAGNOSIS/ENHANCED OBD/DTC INFO/PENDING DTCS.

  A pending DTC indicates that a monitor has failed during the first drive cycle (trip 1).

  During the second drive cycle, there are 2 possibilities: 1) if the same failure occurs again (trip 2), the pending DTC will remain and a current DTC will be set; or 2) if the same failure does not occur again, the pending DTC will be cleared.

• Check for current DTCs. On the hand-held tester, enter the following menus:

  DIAGNOSIS/ENHANCED OBD/DTC INFO/CURRENT DTCS.

  A current DTC indicates that a monitor has failed for 2 consecutive drive cycles. If 40 consecutive drive cycles pass the monitor, the current DTC will be erased.

• A loose fuel cap may cause an intermittent malfunction. However, even if the fuel cap is loose, do not tighten the cap. Finish the hand-held tester EVAP system check and then repeat the entire inspection.
• Find the output DTC in the chart below to determine which part of the EVAP system may be malfunctioning.

1. CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0441, P0442, P0446 AND/OR P0456)"iquest" 
   1. Read the DTC using the hand-held tester or the OBD II scan tool.

      Result: 

      DTC OUTPUT DISPLAY SPECIFICATION
      
      

      Display (DTC output)	Proceed to
      Only P0441, P0442, P0446 and/or P0456 are output	A
      P0451, P0452 and P0453 are output	B

   HINT:

   If any other DTCs besides P0441, P0442, P0446 and/or P0456 are output, perform the troubleshooting for those DTCs first (reference: P0451, P0452, P0453 are vapor pressure sensor malfunctions).

   1. B : Go to RELEVANT DTC CHART (See  DIAGNOSTIC TROUBLE CODE CHART  ) 
   2. A : Go To Next Step. 
2. CHECK CURRENT DTC AND PENDING DTC (CHECK OUTPUT OF DTC P0441, P0442, P0446, P0456) 
   1. Using the hand-held tester, check for pending DTCs. On the hand-held tester, enter the following menus: DIAGNOSIS/ENHANCED OBD/DTC INFO/PENDING DTCS.
   2. Using the hand-held tester, check for current DTCs. On the hand-held tester, enter the following menus: DIAGNOSIS/ENHANCED OBD/DTC INFO/CURRENT DTCS
   3. Make a note of the pending DTC and current DTC outputs.

      HINT:

      • If a failure is detected, a pending DTC is set and the drive cycle is referred to as trip 1.
      • If the same failure is not detected in the next drive cycle, the pending DTC will be erased.
      • If 2 consecutive drive cycles fail, the pending DTC will remain, the MIL will illuminate and a current DTC will be set.
      • If 3 consecutive drive cycles pass the monitor, the MIL will turn OFF.
      • If 40 consecutive drive cycles pass the monitor, the current DTC will be erased.
   Fig 1: Possible Malfunction Specification Table

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. GO : Go To Next Step. 
3. PERFORM EVAP SYSTEM CHECK 
   1. Perform the LEV II SYS CHECK and follow the procedures on the hand-held tester's display.
   2. Using the LEV II SYS CHECK, read the FTP sensor's value and determine the malfunctioning part.
   3. Based on the LEV II SYS CHECK results, perform appropriate LEV II SYS CHECK sub-diagnostics.
   1. GO : Go To Next Step. 
4. REPEAT EVAP SYSTEM CHECK 
   1. To make sure that the repair has been performed properly, repeat the LEV II SYS CHECK.
   2. Read the FTP sensor's value and check that the system operates normally.
   1. NG : FROM RESULT OF LEV II SYSTEM CHECK, SO APPLICABLE SUB-DIAGNOSTIC 
   2. OK : SYSTEM IS OK, AND CLEAR DTC