Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / How to proceed with troubleshooting
Toyota Corolla (E120): How to proceed with troubleshooting
The hand–held tester can be used at step 3, 4, 5, 7, 10.
1 Vehicle brought to workshop

2 Customer problem analysis

3 Connect hand–held tester to dlc3
Hint
: if the display indicates a communication fault in the tool, inspect dlc3.

4 Check dtc and freeze frame data
Hint
: record or print dtc and freeze frame data, if needed.

5 Clear dtc and freeze frame data

6 Visual inspection

7 Setting check (test) mode diagnosis

8 Problem symptom confirmation
Hint
: if the engine does not start, perform steps 10 and 12 first.
| A | Malfunction does not occur |
| B | Malfunction occurs |
B go to step 10

9 Symptom simulation

10 Dtc check
| A | Malfunction code |
| B | No code |
B go to step 12

11 Dtc chart

Go to step 14
12 Basic inspection
| A | Wrong parts not confirmed |
| B | Wrong parts confirmed |
B go to step 17

13 Problem symptoms table
| A | Wrong circuit confirmed |
| B | Wrong parts confirmed |
B go to step 17

14 Check ecm power source circuit

15 Circuit inspection
| A | Malfunction not confirmed |
| B | Malfunction confirmed |
B go to step 18

16 Check for intermittent problems

Go to step 18
17 Parts inspection

18 Identification of problem

19 Adjustment, repair

20 Confirmation test

End
Other materials:
Inspection
1. Inspect front seat inner belt assy lh
When fastening the seat belt (buckle switch on).
Inspect the continuity and resistance between the
terminals.
Standard:
If the result is not as specified, replace the inner belt.
When releasing the seat belt (buckle switch ...
Circuit description
Refer to dtc p0115
Dtc no.
Dtc detection condition
Trouble area
P0125
If the engine coolant temperature (ect) was less than –6.6 °C
(20 °F) when starting the engine, and 20 minutes after the engine
start, the ect sensor still indicates below 20 °C (68 ...
Engine immobilizer system
The vehicle's keys have
built-in transponder chips
that prevent the engine from
starting if a key has not
been previously registered
in the vehicle's on-board
computer.
Never leave the keys inside
the vehicle when you leave
the vehicle.
This system is designed to
help prevent vehicle theft
but doe ...


