Engine Controls - Pin Voltage Charts: Introduction

Pin voltage charts are supplied to reduce diagnostic time. Checking pin voltages at the Powertrain Control Module (PCM) determines whether it receives and transmits proper signals. Charts may also help determine if PCM harness is shorted or open.

Diagnostic values are based on engine at normal operating temperature. Key On Engine Off (KOEO) and hot idle tests were recorded with transmission lever in Park (A/T) or Neutral (M/T) position. M/T vehicles use 3rd gear for 30 MPH values and 4th gear for 55 MPH values.

Reference values may differ because of component tolerances, driving conditions, or weather. Intake Air Temperature (IAT) and Engine Coolant Temperature (ECT) values may vary greatly with temperature. The values given were recorded at approximately 600 feet above sea level, at 50-70°F (10-20°C).

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 may differ slightly because of battery condition or charging rate.