Engine Controls - Pin Voltage Charts: Introduction

Pin voltage charts are supplied to reduce diagnostic time. By checking pin voltages at the Engine Control Module (ECM), it is possible to determine if the ECM is receiving and transmitting proper voltage signals. Charts may also help determine if ECM harness has shorts or opens. Before performing pin voltage tests, ensure engine mechanical condition has been thoroughly inspected and self-diagnostics has been attempted. Technical Service Bulletins (TSBs) may also be helpful in correcting a hard to diagnose problem. For ECM connector terminal identification, see Figure-Figure .