Suzuki Swift Sport 2004 Service & Repair Manual page 54

1A-4 Engine General Information and Diagnosis:
Driving Cycle
A "Driving Cycle" consists of engine startup and engine
shutoff.
2 Driving Cycle Detection Logic
The malfunction detected in the first driving cycle is
stored in ECM memory (in the form of pending DTC) but
the malfunction indicator lamp does not light at this time.
It lights up at the second detection of same malfunction
also in the next driving cycle.
Pending DTC
Pending DTC means a DTC detected and stored
temporarily at 1 driving cycle of the DTC which is
detected in the 2 driving cycle detection logic.
Freeze Frame Data
ECM stores the engine and driving conditions (in the
form of data as shown in the figure) at the moment of the
detection of a malfunction in its memory. This data is
called "Freeze frame data".
Therefore, it is possible to know engine and driving
conditions (e.g., whether the engine was warm or not,
where the vehicle was running or stopped, where air/fuel
mixture was lean or rich) when a malfunction was
detected by checking the freeze frame data. Also, ECM
has a function to store each freeze frame data for three
different malfunctions in the order as each malfunction is
Priority of freeze frame data:
ECM has 4 frames where the freeze frame data can be stored. The first frame stores the freeze frame data of the
malfunction which was detected first. However, the freeze frame data stored in this frame is updated according to the
priority described. (If malfunction as described in the upper square "1" is detected while the freeze frame data in the
lower square "2" has been stored, the freeze frame data "2" will be updated by the freeze frame data "1".)
Priority
Freeze frame data at initial detection of malfunction among misfire detected (P0300 – P0304), fuel
1
system too lean (P0171) and fuel system too rich (P0172)
2 Freeze frame data when a malfunction other than those in "1" is detected
In the 2nd through the 4th frames, the freeze frame data of each malfunction is stored in the order as each malfunction
is detected. These data are not updated.
Shown in the table are examples of how freeze frame data are stored when two or more malfunctions are detected.
Malfunction detected order
No malfunction
P0401 (EGR)
1
detected
P0171 (Fuel system)
2
detected
P0300 (Misfire)
3
detected
P0301 (Misfire)
4
detected
Freeze frame data in frame 1
Frame 1
Freeze frame data to
be updated
No freeze frame data
Data at P0401 Data at P0401
detection detection
Data at P0171 Data at P0401
detection detection
Data at P0171 Data at P0401
detection detection
Data at P0171 Data at P0401
detection detection
detected. Utilizing this function, it is possible to know the
order of malfunctions that have been detected. Its use is
helpful when rechecking or diagnosing a trouble.
[A]
[A]: 1st or 2nd in parentheses here represents which position in the order
the malfunction is detected.
Frame
Frame 2
1st freeze frame 2nd freeze frame
data
Data at P0171
detection
Data at P0171
detection
Data at P0171
detection
I3RB0A110002-01
Frame 3 Frame 4
3rd freeze frame
data data
— —
—
Data at P0300
detection
Data at P0300
detection