Checking Monitor Status

CHECKING MONITOR STATUS

NOTE: The monitor status (mode 6) is not applicable to the heated oxygen sensor (HO2S). However, HO2S test values can be checked by O2S TEST RESULT (mode 5).

Outline
The monitor result and the test values can be checked with the OBD II scan tool.

The engine control module (ECM) monitors the emissions-related components as the thermostat, catalyst converter and evaporative emissions (EVAP), and determines whether they are functioning normally or not. When finished monitoring, the ECM stores the monitor results and the test values.

The monitor result indicates whether the component is functioning normally or not. The test value is the value that was used to determine the monitor result. If the test value is outside the test limit (malfunction criterion), the ECM determines the component is malfunctioning. Some emissions-related components have multiple test values to determine monitor result. If one of these test values is outside test limit, the ECM determines the component is malfunctioning.

Description




The test value and test limit information are described as shown in the table. This information is included under "MONITOR RESULT" in the emissions-related DTC sections:
- TID (Test Identification Data) is assigned to each emissions-related component.
- TID (Test Limit Type):
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.

- CID (Component Identification Data) is assigned to each test value.
- Unit Conversion is used to calculate the test value indicated on generic OBD II scan tools.

Procedure (using hand-held tester)
a. Connect the hand-held tester to the DLC3.
b. Turn the ignition switch and hand-held tester ON.
c. Clear DTCs.
d. Allow the vehicle to drive, in accordance with the applicable drive pattern described in the READINESS MONITOR DRIVE PATTERN section.




e. Select the hand-held tester menus: DIAGNOSIS, ENHANCED OBD II, MONITOR INFO and MONITOR RESULT. The monitor result appears after the component name.
- INCMP indicates the component has not been monitored yet.
- PASS indicates the component is functioning normally.
- FAIL indicates the component is malfunctioning.




f. Select the component and press ENTER. If the monitor result has been PASS or FAIL, the accuracy test value appears.
- VAL indicates the test value.
- LMT indicates the test limit (malfunction criterion).
- TLT indicates the test limit type.

g. Compare the test value with the test limit.
- 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 higher than the test limit.
- If the test value is on the borderline of the test limit, a malfunction is concealed in the component.

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