Dl-158
Tester
connaclion
7 (8us $ Une) 5
(Signal ground)
-
• (CI>assio Gmund)
'""""' '"'"""'' - Body
Body
5
•
The diagnosis system operates in normal mode
during normal vehicle use, and also has a check
mode for technicians to simulate malfunction symp
toms and perform troubleshooting. Most OTCs use
2-trip detection logic (*) to prevent erroneous
detection. By switching the ECM to check mode
when troubleshooting, the technician can cause the
MIL to light up and for a malfunction that is only de
•
tected once or momentarily.
(TOYOTA hand-held tester) (See page Dl-1 57)
*2-trip detection logic:
When a logic malfunction is first detected, the mal
function is temporarily stored in the ECM memory.
If the same malfunction is detected again during the 2nd test
drive, this 2nd detection causes the MIL to light up .
(b)
Inspect the DLC3.
The vehicle's ECM uses ISO 9141-2 for communication.
The terminal arrangement of OLC3 complies with SAE
J1962 and matches the ISO 91 4 1-2 format.
""'"
Condition
During communication
Always
Always
HINT:
If your display shows "UNABLE TO CONNECT TO VEHICLE"
when you have connected the cable of OBD II scan tool or
TOYOTA hand-held tester to DLC3, turned the ignition switch
•
ON and operated the scan tool, there is a problem on the ve
hicle side or tool side.
•
If communication is normal when the tool is connected to
another vehicle, inspect DLC3 on the original vehicle.
If communication is still not possible when the tool is con
nected connected to another vehicle, the problem is prob
ably in the tool itself, so consult the Service Department
listed in the tool's instruction manual.
Specified condition
Pulse generation
1
n or less
1
nor less
v
9 - 14