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 couplers disconnected from it.
Voltage and signal Check
Wiring Diagram:
1. Remove ECM cover from bracket.
2. Using voltmeter (1) or oscilloscope (2), check voltage at each terminal of couplers connected.
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(*) can not be measured by voltmeter because it is pulse signal. Check it with oscilloscope if necessary.
ECM Connector (Viewed From Harness Side):
Ter. E61-1 - E61-12:
Ter. E61-13 - E61-24:
Ter. E61-25 - E61-35:
ECM Connector "E61"
Ter. C51-3-1 - C51-3-11:
Ter. C51-3-14 - C51-3-26:
ECM Connector "C51-3"
Ter. C51-1-1 - C51-1-13:
Ter. C51-1-14 - C51-1-28:
ECM Connector "C51-1"
Ter. C51-2-1 - C51-2-10:
Ter. C51-2-11 - C51-2-20:
Ter. C51-2-21 - C51-2-30:
ECM Connector "C51-2"
1. Reference waveform No. 1
Throttle position signal for cruise control module at throttle fully closed
2. Reference waveform No. 2
Throttle position signal for cruise control module at throttle fully opened
3. Reference waveform No. 3
Engine revolution (ignition pulse) signal (1) at engine idling
4. Reference waveform No. 4
Engine revolution (ignition pulse) signal (1) at engine idling
5. Reference waveform No. 5
Engine coolant temperature signal for combination meter at engine idling
6. Reference waveform No. 6
CAN communication line signal at engine idling
7. Reference waveform No. 7
Knock sensor signal at engine speed 4000 r/min.
8. Reference waveform No. 8
Knock sensor signal at engine speed 4000 r/min.
9. Reference waveform No. 9
Manifold absolute pressure sensor signal (1) at engine racing
10. Reference waveform No. 10
Mass air flow sensor signal (1) at engine racing