Engine Controls - Pin Voltage Charts: Introduction

Pin voltage charts are supplied (where available) to reduce diagnostic time. Checking pin voltages at the Engine Control Module (ECM) or Powertrain Control Module (PCM) determines whether the ECM/PCM is receiving and transmitting proper voltage signals. Charts may also help determine if ECM/PCM harness has shorts or opens.

NOTE: Unless stated otherwise in testing procedures, all voltage tests should be performed with a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance.

NOTE: This ECM/PCM voltage chart can be used with a digital voltmeter to save time in diagnosis. Voltages on vehicle being tested may vary slightly from these due to battery voltage or alternator charging level.