The following electrical wiring diagram applies for engine control module of Chevrolet Lumina 1992 model year. Here you will find brief illustration of the electrical system and wiring diagram. The chart herein may be used in conjunction with the T-100 Yellow Breakout Box (48921) to obtain voltage present for each circuit listed. Install the BOB between the ECM harness connectors and the ECM, then probe the pin listed under “BOB PIN#”. Voltage may vary due to low battery charge or other reasons, but should be very close.