PINPOINT TEST B: Powertrain Control Module (PCM) Power Relay: Introduction

2007 Ford Focus SES, 4D Sedan, StandardSECTION Introduction
WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
WARNING: This vehicle is equipped with high voltage cables, components, and wiring. 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. Certified rubber insulating gloves and a face shield must be worn when working with the high voltage cables, components, or wiring. The ignition key must be cycled to the OFF position for a minimum of 5 minutes, and the high voltage traction battery service disconnect plug placed in the servicing/shipping position before disconnecting the high voltage cables. Failure to follow these instructions may result in personal injury or death.

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)
Fig 1: Powertrain Control Module Power (PCM Power) Relay Connector - A
GF0001546
Pin Circuit
2 GND (Ground)
1 IGN START/RUN
3 B+ (Battery Positive Voltage)
5 VPWR (Vehicle Power)
Fig 2: Identifying 150 Pin PCM Harness Connectors/Terminals
GF0001539
Pin Circuit
B35, B36 VPWR (Vehicle Power)
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.