Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Pinpoint Test B: Powertrain Control Module (PCM) Power Relay: Introduction: Notes
This pinpoint test is intended to diagnose the following:
- harness circuits: B+, INJPWRM, ISP-R, PCMRC, and VPWR
- PCM power relay (12A646)
- PCM (12A650)
| Vehicle | Connector | Pin | Circuit |
|---|---|---|---|
| Fiesta | A | 1 | VPWR |
| All other vehicles | A | 2 | VPWR |
| Vehicle | Connector | Pin | Circuit |
|---|---|---|---|
| Escape/Kuga | A | 5 2 1, 3 |
VPWR PCMRC B+ |
| Expedition, Focus, MKC, Navigator, Transit, Transit Connect |
B | 5 2 1, 3 |
VPWR PCMRC B+ |
| Explorer, Fusion, MKZ, Taurus 3.5L, Taurus 3.7L |
C | 5 1 2, 3 |
VPWR PCMRC B+ |
| F-650/F-750 | A | 87 85 30, 86 |
VPWR PCMRC B+ |
| F-Series Super Duty, Motorhome/Stripped Chassis/Step Van |
A | 5 1 2, 3 |
VPWR PCMRC B+ |
| Mustang | D | 3 2 1, 5 |
VPWR PCMRC B+ |
| All other vehicles | C | 5 2 1, 3 |
VPWR PCMRC B+ |
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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.
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