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.
1990 Ford Probe GT, AutomaticFACTORY OEM SERVICE PROCEDURE
Engine Controls - Tests W/Codes - 2.2L
- Introduction
- Self-Diagnostic System
- Service Code Description
- Retrieving & Clearing Codes
- Reading Diagnostic Codes
- Test Equipment
- Diagnostic Formats
- Quick Test
- Visual Check & Vehicle Preparation
- Equipment Hook-Up
- Key On Engine Off (KOEO) Self-Test
- Key On Engine Running (KOER) Self-Test
- How To Use Circuit Tests
- Service Code-To-Test Menu
- Circuit Test Information
- Test A1 - Ignition Diagnostic Monitor (IDM)
- Test A2 - Crankshaft Position Sensor (Cps)
- Test A3 - Cylinder Identification No. 1
- Test A4 - Cylinder Identification No. 2
- Test A5 - Knock Sensor (KS) & Knock Control Unit (KCU)
- Test A6 - Vehicle Battery
- Test A7 - Reference Voltage & Signal Return
- Test B1 - Vehicle Speed Sensor (VSS)
- Test B2 - Vane Airflow (VAF) Meter
- Test B3 - Engine Coolant Temperature (ECT) Sensor
- Test B4 - Vane Air Temperature (Vat) Sensor
- Test B5 - Throttle Position Sensor (TPS)
- Test B6 - Barometric Pressure Sensor
- Test C1 - Exhaust Gas/Oxygen (Ego) Sensor
- Test C2 - EGR Valve Position Sensor (EVP)
- Test C3 - Fuel Pressure Regulator Control (PRC)
- Test C4 - Canister Purge (CANP)
- Test C5 - EGR Control & EGR Vent
- Test C6 - EGR Vacuum Release (EVR) Solenoid
- Test D1 - Idle Speed Control (ISC)
- Test D2 - Turbocharger Boost Control Solenoid (Boost)
- Test D3 - Self Test Input (STI)/Self Test Output (STO)
- Wiring Diagrams
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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