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.
1991 Ford Probe GL, AutomaticFACTORY OEM SERVICE PROCEDURE
Engine Controls - Tests W/Codes - EEC
- Introduction
- Self-Diagnostic System
- Retrieving Codes
- Self-Test Procedures
- Code-To-Test Menu
- Clearing Codes
- Summary
- How To Use Circuit Tests
- Test Equipment
- Circuit Tests
- Circuit Test Information
- Test BP - Barometric Pressure Sensor
- Test CID1 - Cylinder Identification No. 1
- Test CID2 - Cylinder Identification No. 2
- Test Cps - Crankshaft Position Sensor
- Test ECT - Engine Coolant Temperature Sensor
- Test Ego - Exhaust Gas/Oxygen Sensor
- Test EVP - EGR Valve Position Sensor
- Test IDM - Ignition Diagnostic Monitor
- Test Kc - Knock Sensor (KS) & Knock Control Unit (KCU)
- Test SCG - Solenoid Controlled By Ground
- Switch Performance Check
- Simulated ECA Solenoid Activation
- Test STG - Switch To Ground
- Test STI - Self-Test Input
- Checking System Integrity
- System Voltage Check
- Test STO - Self-Test Output
- Test STP - Switch To Power
- Test TP - Throttle Position Sensor
- Test VAF - Vane Airflow Meter
- Test Vat - Vane Air Temperature
- Test VSS - Vehicle Speed Sensor
- Test VPWR - Vehicle Power
- Test VREF - Reference Voltage & Signal Return
Factory Service Tools
Use the Manual With the Right Hardware
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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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