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.
Control Unit
An 88-pin control unit is used. See CONTROL UNIT LOCATION table. The control unit uses the following input signals to determine optimum fuel injection and ignition timing: intake airflow, intake air temperature, throttle position, coolant temperature, engine speed, vehicle speed, crankshaft position, knock sensors and exhaust gas oxygen content.
Control unit can operate engine in a "limp mode," allowing vehicle operation despite component failure. Control unit also has adaptive capabilities to compensate for component wear and other factors, such as minor air (vacuum) leaks. Once a fault is recognized, it is stored in control unit memory as a fault code. The system automatically substitutes a fixed replacement value for the incorrect value caused by a defective component or circuit.
An air/fuel ratio of 14.7:1 is maintained under most driving conditions. Maximum engine RPM is limited by the control unit by eliminating power to fuel injectors. The control unit assumes control of the following functions.
A/C Compressor Control, Acceleration Enrichment, Cold Start Control, Deceleration Fuel Cut, Fuel Injection Control, Fuel Tank Vent (Evaporation) Control, Idle Speed Control, Ignition Timing Control and Anti-Knock Function, Ignition Timing/Fuel Injection Intervention Via DWA and On-Board Computer, Oxygen (Sensor) Control, Relay Controls and Self-Diagnostics.
| Application | Location |
|---|---|
| All Models | Inside Box On Right Rear Corner Of Engine Compartment |
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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.