Toyota Corolla Repair Manual: Pre–check
1. Diagnosis check

- Starting diagnosis mode (service check mode)
- turn off the audio system and turn the ig switch to
acc. While pressing the preset switches ”1” and ”6”
at the same time, press ”cd” 3 times.
- Reference:
- beep sound is given 3 times and the system
enters the service check mode.
- It may take about 40 sec. To complete the
check.
- In the service check mode, the system check
and the diagnosis memory check are performed,
and the check results are displayed
in ascending order of the device codes.
(Physical address)

Code no. (Physical address) list

- Finishing diagnosis mode
- press ”cd” for 2 sec. Or more, or turn the ig switch
off.
- Service check mode result display (for checking the current
and the past system conditions)
- press the ”tune” switch to see the check result of
each device.

- Check result display
Display |
Original language |
Meaning |
Action to be taken |
Good |
Good (normal) |
No dtc is detected in both ”system check mode” and
”diagnosis memory mode”. |
– |
Ncon |
No connection |
The system recognized the component when it was registered,
but the component gives no response to the ”diagnosis
mode on request”. |
Check the power source circuit
and the communication
circuit of the device indicated
by the device code
(physical address). |
Echn |
Exchange |
One or more dtc for ”exchange” is detected in either ”system
check mode” or ”diagnosis memory mode”. |
Go to the detail information
mode to check the trouble
area referring to the dtc
list. |
Chec |
Check |
When no dtc is detected for ”exchange”, one or more dtc
for ”check is detected in either ”system check mode” or
”diagnosis memory mode”. |
Go to the detail information
mode to check the trouble
area referring to the dtc
list. |
Old |
Old version |
Old dtc application is identified and dtc is detected in either
”system check mode” or ”diagnosis memory mode”. |
– |
Nres |
No response |
The device gives no response to any one of ”system check
mode on request”, ”system check result request” and
”diagnosis memory request”. |
Check the power source circuit
and the communication
circuit of the device indicated
by the device code
(physical code). |
- To perform the service check again, press the preset
switch ”1”.
- detail information mode (when displaying the troubled
device’s dtc)
- with ”chec” or ”echn” being display, press the
preset switch ”2” to go to the detail information
mode.
- Press the ”tune” switch to display ”system check
result (sys)” and ”diagnosis memory response
(code)”.

- Displayed items in detail information mode
Division code for
dtc display |
Meaning |
Order of detailed information displayed when the
”tune up”
switch is pressed. (The order is reversed when the ”tune
down” switch is pressed.) |
Sys |
System check result is displayed. |
Logical address
dtc |
Code |
Diagnosis memory check result is displayed. |
Logical address
dtc
sub code
connection confirmation number
the number of times of occurrence |
- Check the trouble area referring to the dtc list.
- to return to the service check mode, press the preset
switch ”3”.
- clearing individual dtc memory (when clearing the
memory of dtc detected in the pest individually)
- ) press the preset switch ”5” for 2 sec. Or more while
the ”echn” is displayed in the service check mode
or during the detail information mode.
Hint
:
- beep sound is given once when the dtc memory is completely
cleared.
- When dtc memory is cleared, only the component code
(physical address) is displayed for the target component.
- To check dtc, press the preset switch ”1” and perform the
service check again.
- clearance of all dtc memory (when clearing all the
memory of dtc detected in the past)
- start the diagnosis mode after repairing the trouble
area.
- Press the preset switch ”5” for 2 sec. Or more. (”Clr”
is displayed at this time.)
Hint
:
- beep sound is given once when the dtc memory is completely
cleared.
- When dtc memory for all the device is cleared, only the
component codes (physical address) are displayed.
- Press the preset switch ”1” to perform the service
check again, and check that no dtc is displayed for
all the component codes. (Physical address)
2. Identification of noise source
- Identify the condition under which the noise occurs, and
check the noise filter on the related part.

- Reference:
- make sure first that there is no noise from outside.
- Failing to do so makes the noise source detection
difficult and leads to misunderstanding.
- The noise should be removed in descending order
of loudness.
- Setting the radio untuned makes noise noticeable,
making the recognition of the phenomenon easier.
1 Vehicle brought to workshop
2 Customer problem analysis
3 Check and clear dtc
4 Problem symptom confirmation
Symptom does not occur (go to
step 5)
5 Symptom simulation
6 Dtc check ...
Terms
Terms
Physical address
Three–digit code (shown in hexadecimal) which is given to each
component comprising
the avc–lan.
Corresponding to the function, i ...
Other materials:
No sound is heard from speaker in all modes
Wiring diagram
Inspection procedure
1 Check lcd (liquid crystal display) for lighting
Lcd illumination check
turn the ignition switch acc.
Turn the radio receiver assembly on.
Standard: lcd illumination of the radio receiver assembly light.
2 Control fader and ...
Inspection procedure
Hint:
troubleshoot each trouble symptom in accordance with the chart below.
1 Clear dtc
Connect the hand–held tester or the obd ii scan tool to the dlc 3.
turn the ignition switch on and push the hand–held tester or the
obd ii scan tool main switch on.
read the dtc .
& ...
Circuit description
The fuel trim is related to the feedback compensation value, not to the basic
injection time. The fuel trim includes
the short–term fuel trim and the long–term fuel trim.
The short–term fuel trim is the short–term fuel compensation used to maintain
the air–fuel ratio at stoichiometric
air–f ...