Pin Voltage Charts

Pin voltage charts are supplied to reduce diagnostic time. Checking pin voltages at the ECU determines whether it is receiving and transmitting proper voltage signals. Charts may also help determine if ECU harness is shorted or opened.

NOTE: All voltage tests should be performed with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in testing procedures. Voltage readings may vary slightly due to battery condition or charging rate.

ECU circuits are checked at the ECU connector under one or more the following conditions: ignition off, ignition on and engine off, or ignition on and engine running. See Fig 1 -Fig 3 . Test between indicated terminal No. and body ground. When testing pin voltage, carefully backprobe terminal at harness side of ECU connector.
If voltage is not as specified, test and repair, or replace, circuit or affected component. Retest circuit to verify repair has been made. Unless stated otherwise, perform all tests with ECU harness connected.

Fig 1: Identifying ECU Connector Terminals

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Fig 2: Identifying ECU Circuits & Pin Voltage Chart(1 of 2)

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Fig 3: Identifying ECU Circuits & Pin Voltage Chart(2 of 2)

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