Suzuki SX4 Service Manual page 56

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1A-6 Engine General Information and Diagnosis:
• As a condition for detecting a malfunction in some
areas in the system being monitored by ECM and
turning ON the malfunction indicator lamp (1) due to
that malfunction, 2 driving cycle detection logic is
adopted to prevent erroneous detection.
• When a malfunction is detected, engine and driving
conditions then are stored in ECM memory as freeze
frame data. (For the details, refer to description on
"Freeze Frame Data: ".)
• It is possible to communicate via DLC (3) by using not
only SUZUKI scan tool (2) but also CAN
communication OBD generic scan tool. (Diagnostic
information can be accessed by using a scan tool.)
Warm-Up Cycle
A warm-up cycle means sufficient vehicle operation such
that the coolant temperature has risen by at least 22 °C
(40 °F) from engine starting and reaches a minimum
temperature of 70 °C (160 °F).
Driving Cycle
A "Driving Cycle" consists of engine startup and engine
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".)
Freeze frame data at initial detection of malfunction among misfire detected (P0300 – P0304), fuel
system too lean (P0171) and fuel system too rich (P0172)
Freeze frame data when a malfunction other than those in "1" is detected
Freeze frame data in frame 1
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
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.
For example


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