Engine Controls - Tests W/Codes - EFI

• Introduction
• Ecu Location
• Operation
  • Hard Failures
  • Intermittent Failures
  • Check Engine Light
• Retrieving Trouble Codes
  • Notes
  • Notes On Trouble Codes
  • Clearing Trouble Codes
  • Repair Procedure
• Trouble Code Charts
• Diagnostic Circuit Check
  • Notes
  • 1989 Ecu Terminal Identification
  • 1990 Ecu Terminal Identification
• Diagnostic Circuit Tests
  • Test 1 - Ecu Power Source
  • Test 2 Or Code 11 - Ecu (B+) Circuit
  • Code 12, 13 - Rpm Signal
  • Code 14/Test No. 3 - Ignition Signal
  • Test 4 Or Code 21, 27 - Oxygen Sensor Signal
  • Test 5 Or Code 22 - Coolant Temperature Sensor Signal
  • Test 6 Or Code 24 - Intake Air Temp Sensor Signal
  • Code 25 - Lean Air/Fuel Mixture
    • Probable Causes:
  • Code 26 - Rich Air/Fuel Mixture
    • Probable Causes:
  • Test 7 Or Code 31, 32 - Airflow Meter Signal
  • Throttle Position Sensor (TPS) Signal, 4-CYL Without Electronic Controlled Transaxle (ECT)
  • 4-CYL With Electronic Controlled Transaxle (ECT)
  • V6 With Electronic Controlled Transaxle (ECT)
  • Code 42 - Vehicle Speed Sensor (VSS) Signal
    • Notes
    • Probable Causes:
  • Test 9 Or Code 43 - Starter Signal
  • Code 51 - Switch Signal
    • Probable Causes:
  • Code 52 & 53 - Knock Sensor Signal
    • Probable Causes:
  • Test 10 Or Code 71 - EGR System Malfunction
  • Test 11 - Injector Circuit
  • Test 12 - Idle Speed Control Circuit
  • Test 13 - "Check Engine" Light Circuit
  • Test 14 - A/C Switch Circuit
• Summary
  • No Codes Present, DRIVEABILITY Complaint Still Present