DIAGNOSTIC METHOD Subaru Forester SH

DIAGNOSTIC METHOD

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Low Duty ratio > or = 62 % Variable valve lift diagnosis oil pressure switch OFF High Duty ratio < 33 % Variable valve lift diagnosis oil pressure switch ON Time Needed for Diagnosis: Low side: 784 ms High side: 3000 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Low Duty ratio > or = 62 % Variable valve lift diagnosis oil pressure switch ON High Duty ratio < 33 % Variable valve lift diagnosis oil pressure switch OFF Time Needed for Diagnosis: Low side: 208 ms High side: 3000 ms

Note. For the detection standard, refer to DTC P0026. Refer to DTC P0026 INTAKE VALVE CONTROL SOLENOID CIRCUIT RANGE/PERFORMANCE (BANK 1) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Detect functional errors of the front oxygen (A/F) sensor heater.

Judge as NG when it is determined that the front oxygen (A/F) sensor impedance is large when looking at engine status such as deceleration fuel cut.

Scheme 77

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Front oxygen (A/F) sensor impedance 50 ohms Time Needed for Diagnosis: 10000 ms Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Front oxygen (A/F) sensor impedance < or = 50 ohms Time Needed for Diagnosis: 10000 ms

Detect front oxygen (A/F) sensor heater open or short circuit.

The front oxygen (A/F) sensor heater performs duty control, and the output terminal voltage at ON is 0 V, and the output terminal voltage at OFF is the battery voltage.

Judge as NG when the terminal voltage remains Low.

Scheme 78

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage level Low Front oxygen (A/F) sensor heater control duty < 87.5 % Time Needed for Diagnosis: 4 ms x 250 time(s) Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage level High Time Needed for Diagnosis: Less than 1 second

Detect front oxygen (A/F) sensor heater open or short circuit.

The front oxygen (A/F) sensor heater performs duty control, and the output terminal voltage at ON is 0 V, and the output terminal voltage at OFF is the battery voltage.

Judge as NG when the terminal voltage remains High.

Scheme 79

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage level High Front oxygen (A/F) sensor heater control duty > or = 12.5 % Time Needed for Diagnosis: 4 ms x 500 time(s) Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage level Low Time Needed for Diagnosis: Less than 1 second

Detect the rear oxygen sensor heater open or short circuit.

The rear oxygen sensor heater performs duty control, and the output terminal voltage at ON is 0 V, and the output terminal voltage at OFF is the battery voltage.

Judge as NG when the terminal voltage remains Low.

Scheme 80

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage level Low Rear oxygen sensor heater control duty < 75 % Time Needed for Diagnosis: 8 ms x 320 time(s) Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage level High Time Needed for Diagnosis: Less than 1 second

Detect the rear oxygen sensor heater open or short circuit.

The rear oxygen sensor heater performs duty control, and the output terminal voltage at ON is 0 V, and the output terminal voltage at OFF is the battery voltage.

Judge as NG when the terminal voltage remains High.

Scheme 81

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage level High Rear oxygen sensor heater control duty > or = 20 % Time Needed for Diagnosis: 8 ms x 320 time(s) Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage level Low Time Needed for Diagnosis: Less than 1 second

Detect problems in the intake manifold pressure sensor output properties.

Judge as NG when the intake air pressure AD value is Low whereas it seemed to be High from the viewpoint of engine condition, or when it is High whereas it seemed to be Low from the engine condition.

Scheme 82

1. Abnormality Judgement Judge as NG when Low side or High side becomes NG. If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Low Engine speed < 2500 RPM Throttle position > or = 12° Output voltage < 1.63 V Engine load 0.6 g/rev (0.02 oz/rev) High Engine speed 600 RPM - 900 RPM Throttle position < 2.44° Output voltage > or = 3.4 V Engine load < 0.4 g/rev (0.01 oz/rev) Time Needed for Diagnosis: Low side: 3000 ms High side: 7000 ms Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK and clear the NG when both Low side and High side become OK. If the duration of time while the following conditions are met is longer than the time indicated, judge as OK. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Low Engine speed < 2500 RPM Throttle position > or = 12° Output voltage > or = 1.63 V Engine load 0.6 g/rev (0.02 oz/rev) High Engine speed 600 RPM - 900 RPM Throttle position < 2.44° Output voltage < 3.4 V Engine load < 0.4 g/rev (0.01 oz/rev) Time Needed for Diagnosis: Low side: Less than 1 second High side: Less than 1 second

Detect the open circuit of the oil switching solenoid valve.

Judge as NG when the current is small even though the output duty is large.

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Duty ratio > or = 30 % Control current < 0.026 A Time Needed for Diagnosis: 2000 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value |Oil switching solenoid valve target current value - Oil switching solenoid valve current value| < 0.08 A Target current > or = 0.11 A Time Needed for Diagnosis: 2000 ms

Detect short circuits of the oil switching solenoid valve.

Judge as a short NG when the current is large even though the output duty is small.

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Duty ratio < 7 % Control current > or = 0.465 A Time Needed for Diagnosis: 2000 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value |Oil switching solenoid valve target current value - Oil switching solenoid valve current value| < 0.08 A Time Needed for Diagnosis: 2000 ms

Note. For the detection standard, refer to DTC P0076. Refer to DTC P0076 INTAKE VALVE CONTROL SOLENOID CIRCUIT LOW (BANK 1) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Note. For the detection standard, refer to DTC P0077. Refer to DTC P0077 INTAKE VALVE CONTROL SOLENOID CIRCUIT HIGH (BANK 1) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Detect the malfunction of air flow sensor output properties.

Judge as a low side NG when the air flow voltage indicates a small value regardless of running in a state where the airflow voltage increases. Judge as a high side NG when the airflow voltage indicates a large value regardless of running in a state where the air flow voltage decreases. Judge air flow sensor property NG when the Low side or High side becomes NG.

Scheme 83

1. Abnormality Judgement Judge as NG when Low side or High side becomes NG. If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Low Output voltage < 1.49 V Engine speed > or = 2000 RPM Throttle opening angle > or = 12° Intake manifold pressure > or = 66.7 kPa (500 mmHg, 19.7 inHg) High (1) Output voltage > or = 2.66 V Engine speed 600 RPM - 900 RPM Throttle opening angle < 2.44 ° Intake manifold pressure < 40 kPa (300 mmHg, 11.8 inHg) High (2) Output voltage > or = 1.45 V Engine speed 600 RPM - 900 RPM Throttle opening angle < 2.44 ° Intake manifold pressure < 40 kPa (300 mmHg, 11.8 inHg) Fuel system diagnosis Rich side malfunction Time Needed for Diagnosis: Low: 5000 ms High: 10000 ms Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK and clear the NG when both Low side and High side become OK. Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Low Output voltage > or = 1.49 V Engine speed > or = 2000 RPM Throttle opening angle > or = 12° Intake manifold pressure > or = 66.7 kPa (500 mmHg, 19.7 inHg) High Output voltage < 2.66 V Engine speed 600 RPM - 900 RPM Throttle opening angle < 2.44 ° Intake manifold pressure < 40 kPa (300 mmHg, 11.8 inHg) Fuel system diagnosis Rich side normal Time Needed for Diagnosis: Low. Less than 1 second High: Less than 1 second

Detect open or short circuits of the air flow sensor.

Judge as NG if out of specification.

Scheme 84

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage < or = 0.22 V Time Needed for Diagnosis: 500 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage 0.22 V Time Needed for Diagnosis: Less than 1 second

Detect open or short circuits of the air flow sensor.

Judge as NG if out of specification.

Scheme 85

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage > or = 4.179943192 V Time Needed for Diagnosis: 500 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage < 4.179943192 V Time Needed for Diagnosis: Less than 1 second

Detect the open or short circuit of intake manifold pressure sensor.

Judge as NG if out of specification.

Scheme 86

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage < or = 0.573 V Time Needed for Diagnosis: 500 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage 0.573 V Time Needed for Diagnosis: Less than 1 second

Detect the open or short circuit of intake manifold pressure sensor.

Judge as NG if out of specification.

Scheme 87

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage > or = 4.38757221 V Time Needed for Diagnosis: 500 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage < 4.38757221 V Time Needed for Diagnosis: Less than 1 second

Detect the malfunction of intake air temperature sensor output property.

Judge as NG when the intake air temperature is not varied whereas it seemed to be varied from the viewpoint of engine condition.

Scheme 88

1. Abnormality Judgement Judge as NG when the following conditions are established. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage difference between Max. and Min. < 0.02 V (Equivalent to approximately 0.5°C (0.9°F) near 25°C) Time Needed for Diagnosis: Less than 1 second Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK and clear the NG if the following conditions are established. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage difference between Max. and Min. > or = 0.02 V Time Needed for Diagnosis: Less than 1 second

Detect open or short circuit of the intake air temperature sensor.

Judge as NG if out of specification.

Scheme 89

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage < 0.230975449 V Time Needed for Diagnosis: 500 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage > or = 0.230975449 V Time Needed for Diagnosis: Less than 1 second

Detect open or short circuit of the intake air temperature sensor.

Judge as NG if out of specification.

Scheme 90

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage > or = 4.716 V Time Needed for Diagnosis: 500 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage < 4.716 V Time Needed for Diagnosis: Less than 1 second

Detect the open or short circuit of the engine coolant temperature sensor.

Judge as NG if out of specification.

Scheme 91

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage < 0.264738528 V Time Needed for Diagnosis: 500 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage > or = 0.264738528 V Time Needed for Diagnosis: Less than 1 second

Detect the open or short circuit of the engine coolant temperature sensor.

Judge as NG if out of specification.

Scheme 92

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage > or = 4.716 V Time Needed for Diagnosis: 500 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Output voltage < 4.716 V Time Needed for Diagnosis: Less than 1 second

Detect the open or short circuit of throttle position sensor 1.

Judge as NG if out of specification.

Scheme 93

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Sensor 1 input voltage < or = 0.217 V Time Needed for Diagnosis: 24 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Sensor 1 input voltage 0.217 V Time Needed for Diagnosis: 24 ms

Detect the open or short circuit of throttle position sensor 1.

Judge as NG if out of specification.

Scheme 94

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Sensor 1 input voltage > or = 4.858 V Time Needed for Diagnosis: 24 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Sensor 1 input voltage < 4.858 V Time Needed for Diagnosis: 24 ms

Detect the malfunction of engine coolant temperature output property.

Judge as NG when the engine coolant temperature does not rise in driving conditions where it should.

Scheme 95

1. Abnormality Judgement Judge as NG if the criteria below are met. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Engine coolant temperature < 20 °C (68 °F) Timer for diagnosis after engine start > or = Judgement 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 counts up as follows. 64 milliseconds + TWCNT milliseconds (at the time of 64 milliseconds) TWCNT is defined as follows, TWCNT = 0 at idle switch ON, TWCNT show on the following table at idle switch OFF. VEHICLE SPEED REFERENCE Vehicle speed km/h (MPH) 0 (0) 8 (5) 16 (9.9) 24 (14.9) 32 (19.9) 40 (24.9) 48 (29.8) 56 (34.8) Temperature °C (°F) -20 (-4) 0 ms 32.076 ms 39.977 ms 47.879 ms 82.544 ms 117.209 ms 154.214 ms 185.26 ms -10 (14) 0 ms 25.704 ms 33.606 ms 41.508 ms 68.52 ms 95.532 ms 125.667 ms 155.802 ms 0 (32) 0 ms 17.646 ms 25.548 ms 33.45 ms 53.652 ms 73.855 ms 97.12 ms 120.386 ms 10 (50) 0 ms 7.901 ms 15.802 ms 23.704 ms 37.941 ms 52.177 ms 68.573 ms 82.538 ms 20 (68) 0 ms 7.901 ms 15.802 ms 23.704 ms 37.941 ms 52.177 ms 68.573 ms 82.538 ms Judgement value of timer after engine starting t = 573669 ms - 33924 ms x Ti Ti: The lowest coolant temperature after engine start Time Needed for Diagnosis: Less than 1 second Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK and clear the NG when the malfunction criteria below are met. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Engine coolant temperature > or = 20 °C (68 °F) Time Needed for Diagnosis: Less than 1 second

Detect the malfunction of the engine coolant temperature sensor characteristics.

Memorize the engine coolant temperature and fuel temperature at the last engine stop, and use them to judge as NG when the engine coolant temperature does not decrease when it should.

Scheme 96

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Engine coolant temperature at the last engine stop - Minimum engine coolant temperature after the engine start < 2.5 °C (36.5 °F) Fuel temperature at the last engine stop - Fuel temperature > or = 5 °C (41 °F) Intake air temperature - Fuel temperature < 2.5 °C (36.5 °F) Fuel temperature < 35 °C (95 °F) Time Needed for Diagnosis: 2500 ms Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Engine coolant temperature at the last engine stop - Minimum engine coolant temperature after the engine start > or = 2.5 °C (36.5 °F) Time Needed for Diagnosis: Less than 1 second

Detect malfunctions of the thermostat function.

Judge as NG when the engine coolant temperature is lower than the estimated engine coolant temperature and the difference between them is large. Judge as OK when the engine coolant temperature becomes to 75°C (167°F), and the difference is small, before judging NG.

Scheme 97

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Battery voltage > or = 10.9 V Estimate ambient temperature > or = -7°C (19.4°F) Thermostat malfunction diagnosis Incomplete Engine coolant temperature at engine starting < 55°C (131 °F) Estimated coolant temperature > or = 75°C (167°F) Engine coolant temperature < or = 75°C (167°F) (Estimated - measured) Engine coolant temperature 30 °C (86 °F) Vehicle speed > or = 30 km/h (18.6 MPH) Time Needed for Diagnosis: 64 ms x 3 time(s) x 152 time(s) Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Battery voltage > or = 10.9 V Estimate ambient temperature > or = -7°C (19.4°F) Thermostat malfunction diagnosis Incomplete Engine coolant temperature at engine starting < 55°C (131 °F) Engine coolant temperature > or = 75°C (167°F) (Estimated - measured) Engine coolant temperature < or = 30 °C (86 °F) Time Needed for Diagnosis: Less than 1 second

Detect the open or short circuit of sensor.

Judge as NG, when the element voltage is out of the specified range.

Scheme 98

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Input voltage (+) < 1.128 V or Input voltage (-) < 0.23 V or |Input voltage (+) - Input voltage (-)| < 0.644 V Time Needed for Diagnosis: Input voltage (+): 1000 ms Input voltage (-): 1000 ms |Input voltage (+) - Input voltage (-)|: 1000 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Input voltage (+) > or = 1.128 V Input voltage (-) > or = 0.23 V |Input voltage (+) - Input voltage (-)| > or = 0.644 V Time Needed for Diagnosis: Less than 1 second

Detect the open or short circuit of sensor.

Judge as NG, when the element voltage is out of the specified range.

Scheme 99

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Input voltage (+) 3.589 V or Input voltage (-) 3.541 V Time Needed for Diagnosis: Input voltage (+): 1000 ms Input voltage (-): 1000 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Input voltage (+) < or = 3.589 V Input voltage (-) < or = 3.541 V Time Needed for Diagnosis: Less than 1 second

Detect the slow response of front oxygen (A/F) sensor.

Front oxygen (A/F) sensor cover has some ventilation holes for exhaust gas. Clogged ventilation holes are diagnosed.

When the holes are clogged, the A/F output variation becomes slow comparing with the actual A/F variation because oxygen which reaches the zirconia layer is insufficient. Therefore, if the sensor cover holes are clogged, the rich to lean judgement in the ECM is delayed when the actual change from rich to lean occurs.

Judge as NG when the actual movement in comparison to the ECM control amount is slow.

Scheme 100

Scheme 101

Calculate faf difference every 32ms x 4, and the lambda value difference. Calculate the diagnosis value after calculating 1640 time(s).

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value parafca = td2faf/td2lmd 0.4 (U5 model) 0.45 (Other than U5 model) where, td2faf (N) = td2faf (n-1) + |d2faf (n)| td2lmd (N) = td2lmd (n-1) + |d2lmd (n)| add up to 32 ms x 4 x 1640 time(s). d2faf (n) = (faf (n) - faf (n-1)) - (faf (n-1) - faf (n-2)) d2lmd (n) = (lmd (n) - lmd (n-1)) - (lmd (n-1) - lmd (n-2)) faf = main feedback compensation coefficient every 128 milliseconds lmd = output lambda every 128 milliseconds Time Needed for Diagnosis: 32 ms x 4 x 1640 time(s) Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value parafca = td2faf/td2lmd < or = 0.4 (U5 model) < or = 0.45 (Other than U5 model) where, td2faf (N) = td2faf (n-1) + |d2faf (n)| td2lmd (N) = td2lmd (n-1) + |d2lmd (n)| add up to 32 ms x 4 x 1640 time(s). d2faf (n) = (faf (n) - faf (n-1)) - (faf (n-1) - faf (n-2)) d2lmd (n) = (lmd (n) - lmd (n-1)) - (lmd (n-1) - lmd (n-2)) faf = main feedback compensation coefficient every 128 milliseconds lmd = output lambda every 128 milliseconds Time Needed for Diagnosis: 32 ms x 4 x 1640 time(s)

Detect open circuits of the sensor.

Judge as NG when the impedance of the element is large.

Scheme 102

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Battery voltage > or = 10.9 V Time of heater control duty at 70 % or more > or = 36000 ms Front oxygen (A/F) sensor impedance. 500 ohms Time Needed for Diagnosis: 5000 ms Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Battery voltage > or = 10.9 V Front oxygen (A/F) sensor impedance. < or = 500 ohms Time Needed for Diagnosis: Less than 1 second

Detect continuity NG of the oxygen sensor. If the oxygen sensor voltage reading is not within the probable range considering the operating conditions, judge as NG.

Scheme 103

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value DTC High Sensor output voltage 1.2 V P0138 Low Sensor output voltage < 0.03 V P0137 Time Needed for Diagnosis: High: 2500 ms Low (1): 20000 ms Low (2): 40000 ms Low (3): Value from Map Map FUEL CUT TIME Fuel Cut Time (second) 0 2000 10000 Time Needed for Diagnosis (second) 40000 40000 60000 Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value DTC High Sensor output voltage < or = 1.2 V P0138 Low Sensor output voltage > or = 0.03 V P0137 Time Needed for Diagnosis: High: Less than 1 second Low (1): Less than 1 second Low (2): Less than 1 second Low (3): Less than 1 second

Note. For the detection standard, refer to DTC P0137. Refer to DTC P0137 O2 SENSOR CIRCUIT LOW VOLTAGE (BANK 1 SENSOR 2) , Diagnostic Trouble Code (DTC) Detecting Criteria.

Detect the slow response of the oxygen sensor.

Judge as NG if either of the rich to lean response diagnosis or lean to rich response diagnosis is NG, and Judge as OK if both are OK.

[Rich --> lean diagnosis response]

1. Measure the response time for oxygen sensor output changes when the A/F ratio changes to rich to lean. If the measured response time is larger than the threshold value, it is NG. If it is smaller, it is OK.
2. Judge as NG when the oxygen sensor voltage is large (rich) when recovering from a deceleration fuel cut. [Lean --> rich diagnosis response]

1. Measure the response time for oxygen sensor output changes when the A/F ratio changes to lean to rich. If the measured response time is larger than the threshold value, it is NG.
2. Judge as NG when the oxygen sensor voltage remains small when recovering from a deceleration fuel cut.

Measure the response time of the output change of the oxygen sensor when the A/F ratio changes to rich to lean. And Judge as NG when the measured response time is larger than the threshold value.

Scheme 104

When the oxygen sensor output voltage changes from 0.55 V (rich) to 0.15 V (lean), calculate the minimum response time for output change between 0.5 V and 0.2 V for the judgement criteria.

Scheme 105

1. Abnormality Judgement Judge as NG when the judgement value is larger than the threshold value after deceleration fuel cut. Response time (diagnosis value) Threshold value --> abnormal NOTE: Variation time of rear oxygen sensor output voltage is short during fuel cut in deceleration. NG judgement should be performed after deceleration fuel cut. Even without deceleration fuel cut, judge as OK if the value is below the threshold. When the deceleration fuel cut time is 6000 ms or more, judge as NG if the following criteria are met 2000 ms after recovering from the deceleration fuel cut. Judge as NG when the oxygen sensor voltage at recovery from a deceleration fuel cut is large. If the fuel cut time in a deceleration fuel cut is long (6000 ms or more), and even after recovering from a deceleration fuel cut, the oxygen sensor voltage is high (0.55 V or more), judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Shortest time change from rich (0.5 V O 2 output) to lean (0.2 V) when voltage reduces from 0.55 V to 0.15 V 491 ms or Longest time over 0.55 V > or = 2000 ms Time Needed for Diagnosis: 1 time(s) Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.
2. Normality Judgement Regardless of a deceleration fuel cut, if the response time (diagnosis value) when the oxygen sensor voltage has changed from rich to lean is shorter than the threshold value (judgement value), judge as a normal condition. Response time (diagnosis value) < or = Threshold value --> normal Do not judge as a normal condition. Judge as OK and clear the NG if the following conditions are established. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Shortest time change from rich (0.5 V O 2 output) to lean (0.2 V) when voltage reduces from 0.55 V to 0.15 V < or = 491 ms Time Needed for Diagnosis: 1 time(s)

When the oxygen sensor output voltage changes from 0.25 V (lean) to 0.55 V (rich), calculate the minimum response time for output change between 0.3 V and 0.5 V for the judgement criteria.

Scheme 106

1. Abnormality Judgement Judge as NG when the judgement value is larger than the threshold value after deceleration fuel cut. Response time (diagnosis value) Threshold value --> abnormal If the oxygen sensor voltage is small after recovering from a deceleration fuel cut, and remains small, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Shortest time change from lean (0.3 V O 2 output) to rich (0.5 V) when voltage changes from 0.25 V to 0.55 V 2000 ms or Longest time under 0.25 V > or = 120000 ms Time Needed for Diagnosis: 1 time(s) Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Regardless of a deceleration fuel cut, if the response time (diagnosis value) when the oxygen sensor voltage has changed from rich to lean is shorter than the threshold value (judgement value), judge as a normal condition. Response time (diagnosis value) < or = threshold value --> normal Do not judge as a normal condition. Judge as OK and clear the NG if the following conditions are established. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Shortest time change from lean (0.3 V O 2 output) to rich (0.5 V) when voltage changes from 0.25 V to 0.55 V < or = 2000 ms Time Needed for Diagnosis: 1 time(s)

Detect the rear oxygen sensor open or short circuit. Judge as NG when the rear oxygen sensor voltage can be determined to be abnormal considering conditions such as intake air amount, engine coolant temperature, main feedback control and deceleration fuel cut.

Scheme 107

1. Abnormality Judgement If the duration of time while the following conditions are met is longer than the time indicated, judge as NG. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Minimum output voltage 0.15 V or Maximum output voltage < 0.55 V Time Needed for Diagnosis: 200000 ms Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK and clear the NG if the following conditions are established. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value Diagnosis of the rear oxygen sensor voltage low side Incomplete Minimum output voltage < or = 0.15 V Maximum output voltage > or = 0.55 V Time Needed for Diagnosis: Less than 1 second

Detect fuel system malfunction by the amount of main feedback control.

Fuel system is diagnosed by comparing the target air fuel ratio calculated by ECM with the actual air fuel ratio measured by sensor.

1. Abnormality Judgement Compare the diagnosed value (fsobd) with the threshold value, and if a condition meeting the malfunction criteria below continues for 10 s x 5 time(s) or more, judge that there is a fault in the fuel system. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value fsobd = (sglmd - tglmda) + faf + flat > or = Value of Map 2 In this case: sglmd = measured lambda tglmda = target lambda faf = main feedback compensation coefficient every 64 milliseconds flaf = main feedback learning compensation coefficient Map 2 (U5 model) DIAGNOSED VALUE - MAP 2 (U5 MODEL) Amount of air (g (oz)/s) 0 (0) 3.2 (0.11) 6.4 (0.23) 9.6 (0.34) 12.8 (0.45) 16 (0.56) 19.2 (0.68) fsobdL 1 (%) 1.4 1.4 1.332 1.25 1.25 1.25 1.25 Map 2 (Other than U5 model) DIAGNOSED VALUE - MAP 2 (U5 MODEL) Amount of air (g (oz)/s) 0 (0) 3.2 (0.11) 6.4 (0.23) 9.6 (0.34) 12.8 (0.45) 16 (0.56) 19.2 (0.68) fsobdL1 (%) 1.4 1.4 1.332 1.265 1.265 1.265 1.265 Time Needed for Diagnosis: 10 s x 5 time(s) Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK and clear the NG if the continuous time while the following conditions are established is more than the predetermined time. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value fsobd = (sglmd - tglmda) + faf + flaf < 1.2 Time Needed for Diagnosis: 10 s

Detect fuel system malfunction by the amount of main feedback control.

Fuel system is diagnosed by comparing the target air fuel ratio calculated by ECM with the actual air fuel ratio measured by sensor.

1. Abnormality Judgement Compare the diagnosed value (fsobd) with the threshold value, and if a condition meeting the malfunction criteria below continues for 10 s x 5 time(s) or more, judge that there is a fault in the fuel system. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value fsobd = (sglmd - tglmda) + faf + flaf < Value of Map 2 In this case: sglmd = measured lambda tglmda = target lambda faf = main feedback compensation coefficient every 64 milliseconds flaf = main feedback learning compensation coefficient Map 2 DIAGNOSED VALUE - MAP 2 Amount of air (g (oz)/s) 0 (0) 3.2 (0.11) 6.4 (0.23) 9.6 (0.34) 12.8 (0.45) 16 (0.56) 19.2 (0.68) fsobdL 1 (%) 0.6 0.6 0.668 0.735 0.735 0.735 0.735 Time Needed for Diagnosis: 10 s x 5 time(s) Malfunction Indicator Light Illumination: Illuminates when malfunction occurs in 2 continuous driving cycles.

1. Normality Judgement Judge as OK when the malfunction criteria below continues for 10 seconds. Judgement Value JUDGEMENT VALUE REFERENCE Malfunction Criteria Threshold Value fsobd = (sglmd - tglmda) + faf + flaf > or = 0.8 Time Needed for Diagnosis: 10 s

Detect faults in the fuel temperature sensor output properties.

Diagnosis is performed in two methods (drift diagnosis and stuck diagnosis). If either is NG, judge as NG. If both are OK, Judge as OK and clear the NG.