Troubleshooting W/ Volt, Ohmmeter

HINT: The following troubleshooting procedures are designed for inspection of each separate system, therefore the procedure may vary somewhat. However. troubleshooting should be performed referring to the inspection methods described in this manual.






Before beginning inspection, it is best to first make a simple check of the fuses. fusible links and condition of the connectors.

The following troubleshooting procedures are based on the supposition that the trouble lies in either a short or open circuit in a component outside the computer or a short circuit within the computer.

If engine trouble occurs even though proper operating voltage is detected in the computer connector, then it can be assumed that the Electronic Control Module (ECM) is faulty and should be replaced.


PREPARATION

a. Disconnect the connectors from the ECM.






b. Remove the locks as shown in the illustration so that the tester probe(s) can easily come in.

NOTICE: Pay attention to sections A and B in the illustration which can be easily broken.

c. Reconnect the connectors to the ECM.

HINT:

^ Perform all voltage measurements with the connectors connected.

^ Verify that the battery voltage is 11 V or above when the ignition switch is ON.


ECM INSPECTION

Note: Use a voltmeter with high impedance (10 kohms/V minimum) when measuring voltage at ECM terminals.


1. Inspect Voltage Of ECM, ECM Terminal Voltage Values






Check the voltage between each terminal of the wiring connectors.

^ Turn the ignition switch ON.

^ Measure the voltage at each terminal.

NOTE:

^ Perform all voltage measurements with the connectors connected.

^ Verify that the battery voltage is 11 V or more when the ignition switch is ON.


2. Inspect Resistance Of ECM, ECM Terminal Resistance Values

NOTE:

^ Do no touch the ECM terminals.

^ The tester probe should be inserted in the wiring connector from the wiring side.






Check the resistance between each of the terminals of the wiring connector.

^ Disconnect the connectors from the ECM.

^ Measure the resistance at each terminal.