Toyota Corolla Repair Manual: Description
- When troubleshooting obd ii vehicles, the only difference
from the usual troubleshooting procedure is that you
need to connect the vehicle to the obd ii scan tool complying
with sae j1978 or the hand–held tester, and read
various data output from the vehicle’s ecm.
- Obd ii regulations require that the vehicle’s on–board
computer illuminates the malfunction indicator light (mil)
on the instrument panel when the computer detects a
malfunction in the emission control system/components
or in the powertrain control components which affect vehicle
emissions, or a malfunction in the computer. In addition
to the mil illuminating when a malfunction is detected,
the applicable diagnostic trouble codes (dtcs)
prescribed by sae j2012 are recorded in the ecm
memory .
If the malfunction does not reoccur in 3 consecutive trips, the
mil goes off automatically but the dtcs remain recorded in the
ecm memory.

- To check the dtc, connect the hand–held tester or obd
ii scan tool to the data link connector 3 (dlc3) of the vehicle.
The hand–held tester or obd ii scan tool also enables
you to erase the dtc and check the freeze frame
data and various forms of engine data (for operating
instructions, see the obd ii scan tool’s instruction book).
The dtc includes sae controlled codes and manufacturer
controlled codes. Sae controlled codes must be set as
prescribed by the sae, while manufacturer controlled
codes can be set freely by a manufacturer within the prescribed
limits (see the dtc chart on page 05–35).
- The diagnosis system operates in the normal mode during
normal vehicle use. It also has a check mode for technicians
to simulate malfunction symptoms and troubleshoot
it. Most dtcs use the 2 trip detection logic* to
prevent erroneous detection, and to ensure a thorough
malfunction detection. By switching the ecm to the check
mode when troubleshooting, a technician can cause the
mil to illuminate for a malfunction that is only detected
once or momentarily (hand–held tester only) (1).
- *2 Trip detection logic:
when a malfunction is first detected, the malfunction is
temporarily stored in the ecm memory (1st trip). If the
same malfunction is detected again during the second drive test, this second
detection causes the mil to illuminate
(2nd trip) (however, the ignition switch must be
turned off between the 1st trip and 2nd trip).
- Freeze frame data:
the freeze frame data records the engine conditions (fuel
system, calculated load, engine coolant temperature, fuel
trim, engine speed, vehicle speed, etc.) When a malfunction
is detected. When troubleshooting, it is useful for determining
whether the vehicle was running or stopped,
the engine was warmed up or not, the air–fuel ratio was
lean or rich, etc. At the time of the malfunction.
Priorities for troubleshooting:
if troubleshooting priorities for multiple dtcs are given in the
applicable dtc chart, these priorities should be followed.
If no instructions are given, perform troubleshooting for those
dtcs according to the following priorities.
- dtcs other than fuel trim malfunction (dtcs p0171 and
p0172) and misfire (dtcs p0300 to p0304).
- fuel trim malfunction (dtcs p0171 and p0172).
- misfire (dtcs p0300 to p0304).

The vehicle’s ecm uses the iso 9141–2 for communication
protocol. The terminal arrangement of the dlc3 complies
with sae j1962 and matches the iso 9141–2 format.
Hint:
if the display shows una ...
Other materials:
Back up lamp assy lh
Replacement
1. Remove back up lamp assy lh
Remove the service hole cover.
remove the 2 nuts and disconnect the connector.
Using a mouldingremover, remove the 2 clips and back
up light assy lh.
2. Install back up lamp assy lh
Set the 2 clips on the back up ligh ...
Overhaul
1. Remove bench type rear seat cushion assy
Disengage the 2 clamps, and then remove the seat cushion.
2. Remove separate type rear seat back assy
lean the seat back forward.
remove the 2 clips.
remove the 2 bolts and seat back lh.
employ the same manner describ ...
Adjustment
1. Put vehicle these conditions
tire inflation pressure is the specified value .
start the engine.
2. Adjust fog light aim
The fog light aim can be adjusting by moving the aiming
screw in the vertical direction.
Hint:
the optical aim moves upward when turning a scr ...