Toyota ZZT230 series, Repair Manual

Page: 369 / 821

Dl-158
Tester
connaclion
7 (8us $ Une)
5 (Signal ground)
• (CI>assio Gmund)
-
Body
5
'""""' '"'"""'' -Body
..
""'"
•
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 9141-2 format.
Condition Specified condition
During communication Pulse generation
Always
Always
1
n or less
1
nor less
9 - 14
v
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.