Checking Monitor Status

1. INTRODUCTION 

   The Monitor Status (mode 6) allows the OBD scan tool to display the monitor result, test value and test limit (malfunction criterion). A problem in the emission-related components such as the catalyst, EVAP and thermostat can be found by comparing the test value and test limit. The monitor status information is included under the "MONITOR STATUS" in the emission-related DTC sections.

   The ECM (PCM) monitors the emission-related components. After the monitor, the ECM stores the monitor result and test value. The monitor result indicates whether the component is functioning normally or not (PASS or FAIL). The test value is the value that was used to determine the monitor result. When the test value is inside the test limit, the ECM determines the component is functioning normally (PASS). If the test value is outside the test limit, the ECM determines the component is malfunctioning (FAIL).

2. PROCEDURE 
   NOTE: The monitor result and test value are cleared when the ignition switch is turned OFF.
   1. Connect the hand-held tester to the DLC3.
   2. Turn the ignition switch ON.
   3. Clear the DTCs.
   4. Run the vehicle in accordance with the applicable drive pattern described in READINESS MONITOR DRIVE PATTERN .
   5. Select from the tester menus: DIAGNOSIS, ENHANCED OBD II, MONITOR INFO and MONITOR RESULT. The monitor result appears after the component name.

      INCMP: The component has not been monitored yet.

      PASS: The component is functioning normally.

      FAIL: The component is malfunctioning.

      Fig 1: Identifying Monitor Result Display

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   6. Confirm that the component is set to either PASS or FAIL.
   7. Select the component (Label) and press ENTER. The accuracy test value appears when the monitor result is either PASS or FAIL.

      VAL The test value

      LMT: The test limit

      TLT: The test limit type. Either 0 or 1 is displayed.

      Fig 2: Identifying Thermostat Malfunction Display

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   8. If TLT is 0, the component is malfunctioning when the test value is higher than the test limit. If TLT is 1, the component is malfunctioning when the test value is lower than the test limit.
   9. Compare the test value with the test limit. The test value is usually significantly higher or lower than the test limit. If the test value is on the borderline of the test limit, there is a potential malfunction in the component.

HINT:

The monitor result might on rare occasions be PASS even if the MIL is illuminated. This indicates the system malfunctioned on a previous driving cycle. This might be caused by an intermittent problem.