Toyota Corolla (E120): Inspection procedure
Hint
: read freeze frame data using the hand-held tester or the obd ii scan tool. Freeze frame data records the engine conditions 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.
1 Check cooling system
- Check that there is a defect in the cooling system which causes overcool, such as abnormal radiator fan operation, modified cooling system and so on.
2 Inspect thermostat
3 Check other dtc output(in addition to dtc p0128)
- Connect the hand–held tester or the obd ii scan tool to the dlc3.
- turn the ignition switch on and push the hand–held tester or the obd ii scan tool main switch on.
- select the item ”diagnosis / enhanced obd ii / dtc info / current codes”.
- read the dtcs.
Result:
Hint
: if any other codes besides p0128 is output, perform the troubleshooting for those dtcs first.
Replace ecm
Other materials:
Replacement
Hint: components:
1. Precaution
2. Disconnect battery negative terminal
3. Remove air bag front rh sensor
Disconnect the connector from the airbag front rh sensor.
remove the 2 bolts and airbag front rh sensor.
4. Inspect air bag front rh sensor
5. Install air bag front rh ...
Inspection procedure
1 Inspect ecm(+b voltage)
Turn the ignition switch on.
measure the voltage between the terminals of the e4 and
e6 ecm connectors.
Standard:
2 Check harness and connector(ecm – body ground)
Disconnect the e4 ecm connector.
check the resistance between the wire ...
Circuit description
The throttle position sensor is mounted in the throttle body and
detects the throttle valve opening angle.
When the throttle valve is fully closed, a voltage of approximately
0.3 To 1.0 V is applied to terminal vta of the ecm. The voltage
applied to terminal vta of the ecm increases in pro ...