Toyota COMPUTER-CONTROLLED SYSTEM Training Manual page 142

DIAGNOSIS
- "CHECK
ENGINE" Lamp and VF or VF1 Terminal Outpu t
1 . "CHECK ENGINE" LAMP FUNCTION S
LAMP CHECK FUNCTION (T or TE1 terminal off )
The "CHECK ENGINE" lamp goes on when the
ignition switch is turned on to inform the driver
that it has not burnt out . It goes out again when
the engine speed reaches 500 rpm . ( The engine
speed may differ in some engine models . )
Bulb burnout
~*
c 500 rpm
1
-
About
L
cK About 200 rpm
OHP 9 3
WARNING DISPLAY FUNCTION IT or TE1
terminal off)
When trouble occurs and the ECU has detected its
occurrence in one of the input/output signal cir-
cuits connected to the ECU (that is, one of those
marked "ON" in the "CHECK ENGINE" LAMP col-
umn of the table on page 138), the "CHECK
ENGINE" lamp goes on to aleart the driver . The
lamp goes off when conditions are restored to nor-
mal . (This occurs only at an engine speed of 500
rpm or higher) .
DIAGNOSTIC CODE DISPLAY FUNCTION (T or
TE1 terminal on )
If the T or TE1 terminal is connected to the El
terminal (after the ignition switch is turned on),
diagnostic codes are displayed in order from the
smallest to the largest code, with the number of
times the "CHECK ENGINE" lamp blinks
indicating the malfunction code number.
In some engines, a test mode has been provided
which makes the diagnostic system more
sensitive . This system is also provided with a
TE2 terminal in the TDCL or check connector .
See CHECKING AND CLEARING DIAGNOSTIC
CODES (page 159) for the normal mode and test
mode setting procedure and the code output
methods .
REFERENCE
Super Monitor Displa y
When the results of a diagnostic output from
the warning lamp terminal (terminal W) are
displayed on a super monitor, the diagnostic
code display will not appear on the monitor, if
the injection signal is input to the Super
Monitor ECU by the Engine ECU even once .
+ B Super Monito r
Engine ECU
~z
EC U
Switches
J
2-TRIP DETECTION LOGI C
Some diagnostic codes, such as codes 21 and 25
(See page 138), use "2-trip detection logic" .
With this logic, when a malfunction is first
detected, it is temporarily stored in ECU memory .
If the same malfuntion is detected again, this se-
cond detection causes the "CHECK ENGINE"
lamp to light up . (However, the ignition switch
must be turned off between the 1 st time and 2nd
time) .
1st malfunction
detection
(temporaril y
recorded )
IG SW
on
2nd malfunction
detection
(warning
light lights up )
Drivin g
pa
tt
er n
IG SW IG SW IG SW
off on
of f
OHP 9 3
In the test mode, the "CHECK ENGINE" lamp
lights up the 1st time a malfunction is detected .
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