Subaru 2009 IMPREZA Service Manual page 1765

Diagnostic Trouble Code (DTC) Detecting Criteria
CQ:DTC P1410 SECONDARY AIR INJECTION SYSTEM SWITCHING VALVE
STUCK OPEN
1. OUTLINE OF DIAGNOSIS
Always detect abnormality that both combination valve electromagnetic valve and the reed valve are open failure.
Calculate the integrated value of Max./Min. value and output voltage deviation of the secondary air delivery
pipe pressure sensor output voltage in a given time after engine start. Judge as NG if the integrated value
and the difference between Max. and Min. values are large.
2. ENABLE CONDITIONS
Secondary Parameters
Engine speed
Elapsed time after starting the engine
After secondary air system stops
Amount of intake air
Battery voltage
Engine load
After fuel cut
3. GENERAL DRIVING CYCLE
Perform continuous diagnosis when air flow amount is large during the secondary air pump stop after engine start.
4. DIAGNOSTIC METHOD
When both combination valve electromagnetic valve and the reed valve are open failure, the failure appears
as pulses in the secondary air delivery pipe pressure sensor output. Detect abnormality by capturing these
pulses using the following method.
• Abnormality Judgement
Calculate Max./Min. value of the secondary air delivery pipe pressure sensor output voltage and the sum of
the output voltage deviation for the given time. Compare the difference between Max. and Min. values with
threshold value and also compare the sum value with the threshold value. If both values exceed the threshold
value, count up NG counter and then judge as NG if the counter reaches the given times.
Judgement Value
Malfunction Criteria
Pipe inner pressure difference between Max. and Min. > 0.05 V
Sum of the pipe inner pressure variation value every
4 milliseconds
Barometric pressure variation value
Time Needed for Diagnosis: 2000 ms × 20 time(s)
Malfunction Indicator Light Illumination: Illuminates as soon as a malfunction occurs.
• Normality Judgement
Judge as OK and clear NG if neither exceeds the threshold value, or if either of the two exceeds the threshold
value.
Judgement Value
Malfunction Criteria
Pipe inner pressure difference between Max. and Min.
Sum of the pipe inner pressure variation value every
4 milliseconds
Time Needed for Diagnosis: 2000 ms
Enable Condition
500 rpm
and
< 10000 rpm
9000 ms
9000 ms
2 g/s (0.07 oz/s)
and
< 400 g/s (14.11 oz/s)
10.9 V
> 0 g/rev
1000 ms
Threshold Value
> 5 V
< 26.7 kPa (200 mmHg,
7.9 inHg)
Threshold Value
0.05 V
5 V
GD(H4DOTC)-177
GENERAL DESCRIPTION