Inspection of ECM and Its Circuits 1
Inspection of ECM and Its CircuitsECM and its circuits can be checked at ECM wiring couplers by measuring voltage, pulse signal and resistance.
CAUTION: ECM cannot be checked by itself. It is strictly prohibited to connect voltmeter or ohmmeter to ECM with coupler disconnected from it.
Voltage Check
1. Remove ECM (1) from vehicle body.
2. Check voltage and/or pulse signal at each terminal of couplers (2) connected using voltmeter (3) and oscilloscope (4).
NOTE:
- As each terminal voltage is affected by the battery voltage, confirm that it is 11 V or more when ignition switch is turned ON.
- Voltage with asterisk (*) cannot be measured by voltmeter because it is pulse signal.
Check it with oscilloscope if necessary.
Ter. G04-1 - G04-14:
Ter. G04-15 - G04-26:
Ter. G04-27 - G04-35:
Connector "G04"
Ter. C45-1 - C45-17:
Ter. C45-18 - C45-35:
Connector "C45"
Ter. C46-1 - C46-9:
Ter. C46-10 - C46-21:
Ter. C46-22 - C46-31:
Connector "C46"
1.Reference waveform No. 1
Throttle opening signal at throttle fully closed
2.Reference waveform No. 2
Throttle opening signal at throttle fully opened
3. Reference waveform No. 3
Ignition pulse (Engine revolution) signal (2) at engine idling
4.Reference waveform No. 4
Ignition pulse (Engine revolution) signal (2) at engine idling
5.Reference waveform No. 5
Engine coolant temp signal at engine idling
6.Reference waveform No. 6
Engine coolant temp signal at engine idling
7.Reference waveform No. 7
Engine torque reduction signal (1) from TCM
8.Reference waveform No. 8
Engine torque reduction signal from TCM
9.Reference waveform No. 9
VSS signal (1) at 64 km/h (40 mil/h) for A/T vehicle
10.Reference waveform No. 10
VSS signal (1) at 64 km/h (40 mil/h) for A/T vehicle