Toyota ZZT230 series, Repair Manual

Page: 432 / 821

Tester
conneclion
7
(Bus $ Une)-5 (Signal ground)
4
{Chassis Ground)
-
Body
5
{stgnal
Ground)
- Body
Dl-221
DIAGNOSTICS
-
AUTOMATIC TRANSAXLE
0
.....
•
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 DTCs 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 01-220)
•
*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 DLC3 complies with SAE
J1962 and matches the ISO 9141-2 format.
Condition Specified condition
Durii'IO communication
Pulse generation
t nor less
t nor less
1 4 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 manu a!.