2020 Subaru Forester P code Page 57

- 180锟斤拷 Interval Difference Method (MT: 1,800 rpm or less; AT: None)

- 360锟斤拷 Interval Difference Method (whole range)

- 720锟斤拷 Interval Difference Method (3,000 rpm or more)

2. Misfire every time: FTP 1.5 times misfire, Catalyst damage misfire

- 360锟斤拷 Interval Difference Method

2. ENABLE CONDITIONS

3. GENERAL DRIVING CYCLE

- If conditions are met, it is possible to detect the misfires from idling to high engine speed. However, in case any engine load or breakage

occurs, perform with the engine at idle.

- Perform the diagnosis continuously.

4. DIAGNOSTIC METHOD

When a misfire occurs, the engine speed will decrease and the crankshaft position speed will change. Calculate the interval difference value

(diagnostic value) from crankshaft position speed by the following formula, and judge whether a misfire is occurring or not comparing the

calculated result with judgment value. Count the number of misfires, if the misfire ratio is higher during 1000 revs. or 200 revs., judge

corresponding cylinders as NG.

As shown in the following figure, pick a cylinder as the standard and name it omg 0. And the former crankshaft position speed is named omg

1, the second former crankshaft position speed is named omg 2, the third is named omg 3, etc.