POWERTRAIN CONTROL MODULE (PCM)
Note. All vehicles are equipped with either an Engine Control Module (ECM), Powertrain Control Module (PCM) or Vehicle Control Module (VCM) for engine control. Unless specifically stated, references to PCM also apply to ECM and VCM equipped vehicles. Some vehicles equipped with an electronically-controlled transmission also use a Transmission Control Module (TCM) for transmission control.
CONTROL MODULE
| CAUTION | When certain materials rub together, a transfer of electrons from one material to another may occur under special conditions. This causes electrostatic charge (static electricity) build-up in one of the materials. When any conducting material comes in contact with the charged material, electrostatic discharge occurs, transferring electrons to the third material. Electronic components used in control systems are designed to carry very low voltages; a 30-volt charge created by static electricity can cause a total or degrading failure in PCM or other electronic components containing integrated circuits. Before servicing PCM, ground yourself, and ground the work area to discharge stored electricity. |
| Movement | Relative Humidity 10-20% | Relative Humidity 65-90% |
|---|---|---|
| Walking Across Carpet | 35,000 | 1500 |
| Handling Clear Plastic Bag | 20,000 | 1200 |
| Sliding Across Velour Seat | 15,000 | 400 |
| Walking Across Tile/Vinyl | 12,000 | 50 |
| Handling Vinyl Tote Bag | 7000 | 600 |
STATIC CHARGE
| CAUTION | DO NOT remove PCM from packaging until ready to install. Ground static-proof package BEFORE opening. DO NOT touch electrical terminals of components unless properly grounded. DO NOT lay electrical components on car seat, carpeting or dashboard. Use electrostatic protection mat and ground strap whenever possible. (Scheme 24) |
Servicing PCM While Using 3M Anti-Static Mat. Scheme 24
Note. Before replacing PCM, carefully inspect all wiring and control components. Ensure ignition switch is in OFF position when connecting or disconnecting PCM connector.
FUEL SYSTEM PRESSURE RELIEF (TBI)
Disconnect negative battery cable. Loosen fuel filler cap to relieve fuel tank pressure. Fuel pressure is relieved and drops to zero when ignition is turned off. However, to minimize risk of fire and personal injury, cover area to be disconnected with a shop rag.
FUEL PUMP
Note. When installing sending unit, DO NOT fold or twist strainer. This will restrict fuel flow.
THROTTLE BODY (TBI)
Note. Identification number is stamped on throttle body near TP sensor. Identification number must be used for ordering replacement components.
OXYGEN SENSOR
| CAUTION | Oxygen sensor is equipped with a permanent pigtail, which must be protected to prevent damage when removing sensor. |