Initial Inspection and Diagnostic Overview

CAUTION: Short-circuiting the positive (+) probe of a testing device between a connector terminal and ground could damage the vehicle wiring, the sensor, the Electronic Control Unit (ECU) or all three. Additionally, if resistance and continuity checks are performed on the wrong terminals, damage to the vehicle wiring, sensors, ECU, and/or ohmmeter may occur.

Voltage Measurements
If voltage readings differ from Normal Condition values, check related sensors, actuators, and wiring, then replace or repair.
After repair or replacement, recheck with the voltmeter to confirm that the repair has corrected the problem.

Checking At ECU Terminals
Terminal numbers for the ECU connectors, inspection items and standard values have been provided in the charts as reference information.

Performing ECU Terminal Voltage Checks
1. Connect a needle-nosed wire probe or paper clip to a voltmeter probe.
2. Insert the needle-nosed wire probe into each of the ECU connector terminals from the wire side, and measure the voltage while referring to the testing information charts. Measure voltage with the connectors connected.

NOTE: You may find it convenient to pull out the ECU to make it easier to reach the connector terminals.

Terminal Resistance and Continuity Checks
1. Turn the ignition switch to off.
2. Disconnect the ECU connector.
3. Measure the resistance and check for continuity between the terminals of the ECU harness-side connector while referring to the check chart.
4. If the ohmmeter shows any deviation from the Normal Condition value, check the corresponding sensor, actuator and related electrical wiring, then repair or replace.
5. After repair or replacement, recheck with the ohmmeter to confirm that the repair has corrected the problem.