Data Link Connector 3 Inspection - Toyota 1 MZ–FE Manual

Terminal No. Connection
Bus (+) Line
Chassis Ground
Signal Ground
Battery Positive
1MZ–FE ENGINE – DIAGNOSIS SYSTEM
Freeze frame data:
Freeze frame data records the engine condition when a
misfire (DTC P0300 – P0306) or fuel trim malfunction
(DTC P0171, P0172), or other malfunction (first malfunc–
tion only), is detected.
Because freeze frame data records the engine conditions
(fuel system, calculator load, engine coolant temperature,
fuel trim, engine speed, vehicle speed, etc.) when the mal–
function is detected, when troubleshooting it is useful for
determining whether the vehicle was running or stopped,
the engine warmed up or not, the air–fuel ratio lean or rich,
etc. at the time of the malfunction.
Priorities for Troubleshooting:
If troubleshooting priorities for multiple diagnostic codes
are given in the applicable diagnostic chart, these should be
followed.
If no instructions are given, troubleshoot diagnostic trouble
codes according to the following priorities.
(1) Diagnostic trouble codes other than fuel trim malfunc–
tion (DTC P0171, P0172) and EGR (DTC P0401, P0402) and
misfire (DTC P0300 – P0306).
(2) Fuel trim malfunction (DTC P0171, P0172) and EGR (DTC
P0401, P0402)
(3) Misfire (DTC P0300 – P0306).

DATA LINK CONNECTOR 3 INSPECTION

The vehicle's ECM uses V.P.W. (Variable Pulse Width) for
communication to comply with SAE J1850. The terminal ar–
rangement of DLC 3 complies with SAE J1962 and matches
the V. P.W. format.
Voltage or Resistance
Pulse generation
Body Ground 1 0 or less
Body Ground 1 0 or less
Body Ground 9 – 14 V
HINT: If your display shows "UNABLE TO CONNECT TO
VEHICLE" when you have connected the cable of the OBDII
scan tool or TOYOTA hand–held tester to DLC 3, turned the
ignition switch ON and operated the scan tool, there is a
problem on the vehicle side or tool side.
1) If communication is normal when the tool is connected
to another vehicle, inspect DLC 3 on the original vehicle.
2) If communication is still not possible when the tool is
connected to another vehicle, the problem is probably in
the tool itself, so consult the Service Department listed in
the tool's instruction manual.
EG2–401
Condition
During transmission
Always
Always
Always