Engine Controls - Tests W/Codes - CARBURETED

• Introduction
• Ecu Location
• Hard Failures
• Intermittent Failures
• Check Engine Light
• Retrieving Trouble Codes
• Notes On Trouble Codes
• Clearing Trouble Codes
• Repair Procedure
• Summary
  • No Codes Present, DRIVEABILITY Complaint Still Present
• Trouble Code Charts
• Trouble Code Diagnostic Hints - CARBURETED Models
• Circuit Tests
  • Diagnostic Circuit Check
  • Ecu Terminal Identification
  • Test 1 - Ecu (B+) Circuit
  • Test 2 - Ecu Power Source
  • Test 3 Or Code 12 - Ignition & Rpm Signal
  • Code 21 - Oxygen Sensor Signal
    • Probable Causes
  • Test 4 Or Code 22 - Coolant Temperature Switch Signal
  • Test 5 Or Code 25, 26 - Air Fuel Mixture Malfunction
  • Test 6 Or Code 31 - Vacuum Switch Signal
  • Test 7/Code 41 - Throttle Position Switch Signal
  • Test 8 Or Code 71 - EGR System Malfunction
  • Test 9 Or Code 72 - Fuel Cut Solenoid Signal
  • Test 10 - "Check Engine" Light Circuit
  • Test 11 - Charging System Circuit
  • Test 12 - Throttle Positioner Circuit
  • Test 13 - Cold Enrichment Breaker Circuit
  • Test 14 - A/C Switch Circuit