Millenia L V6-2.5L DOHC (1997)
Powertrain Control Module (PCM): Testing and Inspection
With SST-Engine Signal Monitor (Terminal Voltages)
Inspection Using Engine Signal Monitor
CAUTION: The PCM terminal voltages vary with change in measuring conditions and vehicle conditions. Always carry out a total inspection of the
input systems, output systems, and PCM to determine the cause of trouble. Otherwise, a wrong diagnosis will be made.
1. Disconnect the negative battery cable.
2. Disconnect the PCM connector.
3. Connect the Special Service Tool (Adapter harness) to the PCM connector.
4. Connect the Special Service Tools (Monitor, Engine Signal and Harness adapter, power) to the Special Service Tool (Adapter harness). Use
connector A of the adapter harness for PCM terminals 1A through 1AJ, 2A through 2T, and 3A through 3R. Use connector B for PCM terminals
3B through 3AB and 4A through 4AN.
5. Place the Special Service Tool (Sheet) on the Engine Signal Monitor.
6. Measure the voltage at each PCM terminal by switching the selector switch and the monitor switch.
7. If any incorrect voltage is detected, check related systems, wiring harnesses and connectors referring to the possible malfunction in the terminal
voltage list.
CAUTION:
-
Disconnecting the connectors of the PCM and the Special Service Tool (Adapter harness) while the battery is connected can damage the PCM
and the Special Service Tool. Disconnect the negative battery cable and the Special Service Tool (Harness adapter, power) before
disconnecting the connectors.
-
Applying voltage to terminals A and B of the Engine Signal Monitor can damage the tool.
NOTE:
-
The indicator lights of the Special Service Tool (Monitor, Engine Signal), provided for confirmation of the voltmeter range, is also used for
detection of the pulse such as the fuel injector control signal, which is difficult to detect by using the voltmeter.
-
Terminals A and B of the Special Service Tool (Monitor, Engine Signal) are for connection of an external instrument. By connecting an
external instrument such as a circuit tester or an oscilloscope, various inspections in addition to the measurement of the PCM terminal voltages
are made possible.
