Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Combination meter / Malfunction in tachometer
Toyota Corolla (E120): Malfunction in tachometer
Wiring diagram

Inspection procedure

- Check output value of ecm.
- Connect the hand–held tester to dlc3.
- Turn the ignition switch to on and push the hand–held tester main switch on.
- Select the data list mode on the hand–held tester.


2 Inspect combination meter assy

(Reference) inspection using oscilloscope
- check the input signal waveform.
- Remove the combination meter assy with connectors still connected.
- Connect the oscilloscope to the terminals c9–19 of combination meter assy and body ground.
- Start engine.
- Check the signal waveform.




3 Check harness and connector(between ecm and combination meter assy)
- Remove the combination meter.
- check the continuity between terminals 5 (tach) of ecm and c9–19 of combination meter connector.
Standard: there is continuity.


Check and replace ecm
Other materials:
Inspection procedure
1 Check courtesy lamp switch
Check the courtesy switch, as shown in the illustration
and table.
Standard:
2 Check wire harness (integration relay door courtesy sw)
Disconnect the integration relay and door courtesy connectors.
check the continuity between th ...
Supplemental restraint system
Preparation
Sst
Recomended tools
Equipment
...
Circuit description
The intake air temperature (iat) sensor, mounted on the mass
air flow (maf) sensor, monitors the intake air temperature. The
iat sensor has a thermistor that varies its resistance depending
on the temperature of the intake air. When the air temperature
is low, the resistance in the thermisto ...


