Test B: Powertrain Control Module (PCM) Power Relay

2006 Mercury Grand Marquis V8-4.6L VIN WSECTION Test B: Powertrain Control Module (PCM) Power Relay


PINPOINT TEST B: POWERTRAIN CONTROL MODULE (PCM) POWER RELAY

This pinpoint test is intended to diagnose the following:

^ harness circuits: PCMRC ISP-R
^ vehicle power
^ ignition start/run
^ PCM power relay ground
^ battery positive voltage
^ PCM power relay (12A646)
^ PCM (12A650)

Note: The IGN START/RUN and ground circuits or the B+ and VPWR circuits may be reversed in the harness connector. Refer to the W~nng Diagrams Manual Electronic Engine Control Cell for schematic and connector information.









B1 - B3:





B4 - B5:





B6:





B7 - B8:





B9 - B10:





B11 - B12:





B13 - B14:





B15 - B16:





B17:





RENDER: 1.0x

NO RELATED

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When to See a Mechanic

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

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