PINPOINT TEST B: Powertrain Control Module (PCM) Power Relay: Introduction
Do not disconnect, disable, or touch the high voltage cables, components, or wiring during the module reprogramming procedure because high voltage is present. The high voltage warning labels containing the high voltage symbol are located on each high voltage component. High voltage cables and wiring are orange in color. Failure to follow these instructions may result in personal injury or death.
Appropriate repair methods and procedures are essential for the safe, reliable operation of all motor vehicles, as well as the personal safety of the individual doing the work. This article provides general directions for repairing vehicles with tested, effective techniques. Following them helps to establish reliability. There are numerous variations in procedures, techniques, tools, and parts for repairing vehicles, as well as in the skill of the individual doing the work. This article cannot possibly anticipate all such variations and provide advice or cautions as to each. Accordingly, anyone who departs from the instructions provided in this article must first establish that they compromise neither their personal safety nor the vehicle integrity by their choice of methods, tools, or parts.
This pinpoint test is intended to diagnose the following:
- harness circuits: VPWR, IGN START/RUN, GND and B+
- PCM power relay (12A646)
| Pin | Circuit |
|---|---|
| 2 | GND (Ground) |
| 1 | IGN START/RUN |
| 3 | B+ (Battery Positive Voltage) |
| 5 | VPWR (Vehicle Power) |
| Pin | Circuit |
|---|---|
| B35, B36 | VPWR (Vehicle Power) |