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.
Powertrain Control Module: Notes
Powertrain Control Module (PCM) monitors engine operating conditions by input received from engine sensors. PCM receives input from sensors and other electronic components, such as switches or relays. Based on information received and programmed into its memory, PCM generates output signals to control various components, such as relays, solenoids and actuators.
There are 4 types of PCM used. A 150-pin PCM which has 3 separate electrical harness connectors (Aviator, Explorer, LS, Mountaineer and Thunderbird), a 150-pin PCM which has 3 separate electrical harness connectors (Focus 2.3L), a 122-pin PCM which has 3 separate electrical harness connectors (Expedition and Navigator) and a 104-pin PCM which has one electrical harness connector (all others). See Fig 1-Fig 4 . For PCM location, see POWERTRAIN CONTROL MODULE LOCATION table.
PCM uses a memory integrated circuit chip which stores information for Keep Alive Random Access Memory (KAM). For additional KAM information, see KEEP ALIVE RANDOM ACCESS MEMORY under POWERTRAIN CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS. Flash Electrically Erasable Programmable Read Only Memory (EEPROM) is an Integrated Circuit (IC) within PCM. This IC contains software code required by PCM to control powertrain. For additional EEPROM information, see FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY under POWERTRAIN CONTROL SOFTWARE.
In the event that one or more input sensors fail, PCM initiates an alternative operating procedure called Failure Mode Effects Management (FMEM) to allow the vehicle to maintain driveability. For additional information on FMEM, see FAILURE MODE EFFECTS MANAGEMENT under POWERTRAIN CONTROL SOFTWARE. If PCM detects an engine overheating condition, it activates a fail-safe cooling strategy. For additional information, see FAIL-SAFE COOLING STRATEGY under POWERTRAIN CONTROL SOFTWARE. In the event of PCM failure, Hardware Limited Operation Strategy (HLOS) will be activated. For additional information on HLOS, see HARDWARE LIMITED OPERATION STRATEGY under POWERTRAIN CONTROL MODULE under COMPUTERIZED ENGINE CONTROLS.
| Application | Location |
|---|---|
| Aviator, Blackwood, Expedition, Explorer, Explorer Sport, Explorer Sport Trac, F150 Pickup, Mountaineer & Navigator | Right Rear Of Engine Compartment, Mounted On Cowl |
| Escape, Ranger & Town Car | Center Of Engine Compartment, Mounted On Cowl |
| LS, Sable, Taurus & Windstar | Right Rear Of Engine Compartment, Mounted On Cowl |
| Crown Victoria, Grand Marquis & Marauder | Behind Left Kick Panel, Near Instrument Panel |
| Econoline | Left Rear Of Engine Compartment, Near Brake Master Cylinder |
| Excursion & F250-550 Super-Duty Pickups | Behind Left Side Of Instrument Panel, Near Brake Pedal |
| Focus & Mustang | Behind Right Kick Panel |
| Thunderbird | In Right Side Fenderwell, Behind Right Shock Tower |
| ZX2 | Center Of Instrument Panel, Below Center Console |
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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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