Toyota Corolla (E120) 2002–2008 Repair Manual / Introduction / How to troubleshoot ecu controlled
systems / Circuit inspection
Toyota Corolla (E120): Circuit inspection
How to read and use each page is shown below.

Other materials:
Inspection procedure
1 Inspect dlc3 terminal voltage
Turn the ignition switch to on.
measure voltage between terminals 13 (tc) and 4 (cg) of
dlc3.
Ok:
voltage: 10 – 16 v
2 Check harness and connector(between cruise control ecu assy
and dlc3)
Check for open and short circuit in harness ...
Speedometer sensor (atm)
Replacement
1. Remove air cleaner case
2. Remove air cleaner hose no.1
3. Remove speedometer sensor
disconnect the connector.
remove the bolt and speedometer sensor assembly.
remove the clip and driven gear from the speedometer
sensor.
4. Install speedometer sensor
...
Sound quality is bad only when cd is played(volume is
too low)
Inspection procedure
1 Replace cd with another and recheck
Replace the cd with another and recheck.
Check the installation condition of the radio receiver assembly.
Standard: malfunction disappear.
Check and replace radio receiver assy ...


