Suzuki WagonR+ RB310 Service Manual page 579

6-2-8 ENGINE GENERAL INFORMATION AND DIAGNOSIS (M13 ENGINE)
[A]
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 mal-
function 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 the 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.
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 below. (If
malfunction as described in the upper square "1" below 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".)
[A]: 1st or 2nd in parentheses here represents which position in the order the malfunction
is detected.
PRIORITY FREEZE FRAME DATA IN FRAME 1
1 Freeze frame data at initial detection of malfunc-
tion among misfire detected (P0300-P0304), fuel
system too lean (P0171) and fuel system too rich
(P0172)
2 Freeze frame data when a malfunction other than
those in "1" above is detected