Diagnostic Method
Abnormality Judgment
Judge as NG when the malfunction criteria below are met.
Judgment Value
| Malfunction Criteria | Threshold Value |
|---|---|
| Engine coolant temperature | < 20°C (68°F) |
| Timer for diagnosis after engine start | ≥ Judgment value of timer after engine start |
Timer for diagnosis after engine start
- Timer stop at fuel cut.
- During the driving conditions except a) above, timer count up by 64 milliseconds + TWCNT milliseconds at every 64 milliseconds.
TWCNT is defined as follows,
TWCNT = 0 at idle switch ON, TWCNT show on the following table at idle switch OFF.
| Temperature °C (°F) | Vehicle speed km/h (MPH) | |||||||
|---|---|---|---|---|---|---|---|---|
| 0(0) | 8 (4.97) | 16(9.94) | 24(14.9) | 32(19.9) | 40 (24.9) | 48 (29.8) | 56 (34.8) | |
| -20 (-4) | 0 ms | 37.2 ms | 74.3 ms | 111.4 ms | 126.7 ms | 141.9 ms | 163.6 ms | 185.3 ms |
| -10(14) | 0 ms | 27.4 ms | 54.8 ms | 82.2 ms | 99.7 ms | 117.1 ms | 136.0 ms | 154.8 ms |
| 0(32) | 0 ms | 17.6 ms | 35.3 ms | 52.9 ms | 72.6 ms | 92.3 ms | 108.3 ms | 124.3 ms |
| 10(50) | 0 ms | 7.9 ms | 15.8 ms | 23.7 ms | 45.6 ms | 67.6 ms | 80.7 ms | 93.9 ms |
| 20 (68) | 0 ms | 7.9 ms | 15.8 ms | 23.7 ms | 45.6 ms | 67.6 ms | 80.7 ms | 93.9 ms |
Judgment value of timer after engine starting
t = 429.5 - 28.605 x Ti
Ti is the lowest coolant temperature after starting the engine.
Time Needed for Diagnosis: To be determined. (It is varied by the Min. engine coolant temperature and engine conditions such as vehicle speed and engine coolant temperature.)
Malfunction Indicator Light Illumination: Illuminates when malfunctions occur in 2 continuous driving cycles.
Normality Judgment
Judge as OK and clear the NG when the malfunction criteria below are met.
Judgment Value
| Malfunction Criteria | Threshold Value |
|---|---|
| Engine coolant temperature | ≥ 20°C (68°F) |