Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Checking Monitor Status
The purpose of the monitor result (mode 06) is to allow access to the results for on-board diagnostic monitoring tests of specific components/systems that are not continuously monitored. Examples are catalyst, evaporative emission (EVAP) and thermostat.
The monitor result allows the OBD II scan tool to display the monitor status, test value and test limit. The monitor status is displayed after the vehicle has been driven to run the monitor. When the test value exceeds the test limit, the ECM (PCM) interprets this as a malfunction. When the component is not malfunctioning, if the difference of the test value and test limit is very small, the component will malfunction in the near future.
Perform the following instruction to view the monitor status. Although this instruction references the Lexus/Toyota diagnostic tester, it can be checked using a generic OBD II scan toll. Refer to your scan tool operator's manual for specific procedures.
Test ID $01: Catalyst - A/F sensor type
| TLT | Component ID | Unit Conversion | Unit | Description |
|---|---|---|---|---|
| 0 | $01 | Multiply by 0.0078 | No dimension | Catalyst deterioration level (Bank 1): Determined by waveforms of A/F sensor and O2S |
| 0 | $02 | Multiply by 0.0078 | No dimension | Catalyst deterioration level (Bank 1): Determined by waveforms of A/F sensor and O2S |
Test ID $02: EVAP - Key-off type
| TLT | Component ID | Unit Conversion | Unit | Description |
|---|---|---|---|---|
| 1 | $01 | Multiply by 0.0156 subtract 2 | kPa | Test value for small leak (P0456) |
| 1 | $02 | Multiply by 0.0156 subtract 2 | kPa | Test value for gross leak (P0455) |
| 1 | $03 | Multiply by 0.0156 subtract 2 | kPa | Test value for vacuum pump stuck OFF (P2401) |
| 1 | $04 | Multiply by 0.0156 subtract 2 | kPa | Test value for vacuum pump stuck ON (P2402) |
| 1 | $05 | Multiply by 0.0156 subtract 2 | kPa | Test value for vent valve stuck OFF (P2420) |
| 1 | $06 | Multiply by 0.0156 subtract 2 | kPa | Test value for vent valve stuck ON (P2419) |
| 1 | $07 | Multiply by 0.0156 subtract 2 | kPa | Test value for reference orifice low flow (P043E) |
| 1 | $08 | Multiply by 0.0156 subtract 2 | kPa | Test value for reference orifice high flow (P043F) |
| 1 | $11 | Multiply by 0.0156 subtract 2 | kPa | Test value for purge VSV stuck close (P0441) |
| 1 | $12 | Multiply by 0.0156 subtract 2 | kPa | Test value for purge VSV stuck open (P0441) |
| 1 | $13 | Multiply by 0.0156 subtract 2 | kPa | Test value for insufficient purge flow (P0441) |
Test ID $04: Oxygen sensor heater
| TLT | Component ID | Unit Conversion | Unit | Description |
|---|---|---|---|---|
| 1 | $02 | Multiply by 0.000076 | Amperage | Maximum heater current (Bank 1 Sensor 2) |
Test ID $06: A/F sensor
| TLT | Component ID | Unit Conversion | Unit | Description |
|---|---|---|---|---|
| 0 | $01 | Multiply by 0.000244 | No dimension | Parameter to identify A/F sensor response rate (Bank 1) |
Test ID $07: A/F sensor heater
| TLT | Component ID | Unit Conversion | Unit | Description |
|---|---|---|---|---|
| 1 | $01 | Multiply by 0.00017 | Amperage | Maximum heater current (Bank 1) |
Test ID $08: Thermostat
| TLT | Component ID | Unit Conversion | Unit | Description |
|---|---|---|---|---|
| 1 | $01 | Multiply by 0.625 and subtract 40 | °C | ECT sensor output when estimated ECT reaches malfunction criteria |
- PERFORM MONITOR DRIVE PATTERN NOTE: The monitor results will be lost if the ignition switch is turned OFF.
- Connect the intelligent tester to the DLC3.
- Turn the ignition switch and intelligent tester ON.
- Clear the DTCs.
- Run the vehicle in accordance with the applicable drive pattern described in READINESS MONITOR DRIVE PATTERN .
- ACCESS MONITOR RESULT
- Select from the intelligent tester menus: DIAGNOSIS, ENHANCED OBD II, MONITOR INFO and MONITOR RESULT. The monitor result appears after the component name.
- Confirm that the component is either PASS or FAIL.
- Select the component and press ENTER. The accuracy test value appears when the monitor result is either PASS or FAIL.
- INCMP: The component has not been monitored yet.
- PASS: The component is functioning normally.
- FAIL: The component is malfunctioning.
- VAL: Test value.
- LMT: Test limit (malfunction criterion).
- TLT: 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.
- CHECK COMPONENT STATUS
- Compare VAL with LMT. The VAL is usually significantly higher or lower than LMT.
- If the test value is on the borderline of the test limit, the component will malfunction in the near future.
HINT:
The monitor result might on rare occasions be PASS even if the malfunction indicator lamp (MIL) is illuminated. This indicates that the system malfunctioned on a previous driving cycle. This might be caused by an intermittent problem.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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