Engine Controls - Pin Voltage Charts: Introduction

Pin voltage charts are supplied to reduce diagnostic time. Checking Engine Control Unit (ECU) or Powertrain Control Module (PCM) input and output signals determine if ECU or PCM is receiving and transmitting proper voltage signals. Charts may also help determine if ECU or PCM harness is shorted or opened.

Input and output signals should be checked using appropriate breakout box or signal monitor along with appropriate adapter cable(s). However, if signals are checked at ECM or PCM connector, care should be taken to prevent damage to connector or wiring harness.

NOTE: Unless stated otherwise in testing procedures, perform all voltage tests using a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance. Voltages or values may vary 20% due to battery condition, charging rate or tire sizes, etc.