Notes on Troubleshooting

Fig. 153 Emission Control Unit Test Harness Connections:

1. If the inspection for a particular system requires the ECU test harness, proceed as follows:
a. Remove the drivers seat.
b. Remove the three screws on the control unit cover and remove the cover to expose the control unit connectors.
c. Connect the test harness to the control unit as shown in Fig. 153.

Fig. 154 Proper Wiring Harness Testing Procedure:

2. When testing individual wires to locate a problem, observe the following:
a. Avoid puncturing the insulation of any wire. This can cause corrosion of the wiring which could lead to poor contacts and intermittent electrical problems.
b. When testing connectors (other than those of the ECU test harness), bring the test probe into contact with the terminal from the connector side of the wire harness connector, Fig. 154.
c. When testing female connectors, just touch the test probe lightly to the connector. Do not insert the test probe into the connector as this will deform the terminal and cause a poor connection, and a possible failure of the circuit.